EP1656556A2 - Substrate in the form of a ligate carrier - Google Patents

Substrate in the form of a ligate carrier

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Publication number
EP1656556A2
EP1656556A2 EP04731631A EP04731631A EP1656556A2 EP 1656556 A2 EP1656556 A2 EP 1656556A2 EP 04731631 A EP04731631 A EP 04731631A EP 04731631 A EP04731631 A EP 04731631A EP 1656556 A2 EP1656556 A2 EP 1656556A2
Authority
EP
European Patent Office
Prior art keywords
substrate
ligates
ligands
test sites
substrate according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04731631A
Other languages
German (de)
French (fr)
Inventor
Gerhard Hartwich
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Friz Biochem Gesellschaft fuer Bioanalytik mbH
Original Assignee
Friz Biochem Gesellschaft fuer Bioanalytik mbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Friz Biochem Gesellschaft fuer Bioanalytik mbH filed Critical Friz Biochem Gesellschaft fuer Bioanalytik mbH
Publication of EP1656556A2 publication Critical patent/EP1656556A2/en
Withdrawn legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
    • G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/0046—Sequential or parallel reactions, e.g. for the synthesis of polypeptides or polynucleotides; Apparatus and devices for combinatorial chemistry or for making molecular arrays
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/28—Electrolytic cell components
    • G01N27/30—Electrodes, e.g. test electrodes; Half-cells
    • G01N27/327—Biochemical electrodes, e.g. electrical or mechanical details for in vitro measurements
    • G01N27/3275—Sensing specific biomolecules, e.g. nucleic acid strands, based on an electrode surface reaction
    • G01N27/3276—Sensing specific biomolecules, e.g. nucleic acid strands, based on an electrode surface reaction being a hybridisation with immobilised receptors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00583—Features relative to the processes being carried out
    • B01J2219/00603—Making arrays on substantially continuous surfaces
    • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00583—Features relative to the processes being carried out
    • B01J2219/00603—Making arrays on substantially continuous surfaces
    • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
    • B01J2219/0061—The surface being organic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00583—Features relative to the processes being carried out
    • B01J2219/00603—Making arrays on substantially continuous surfaces
    • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
    • B01J2219/00612—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports the surface being inorganic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00583—Features relative to the processes being carried out
    • B01J2219/00603—Making arrays on substantially continuous surfaces
    • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
    • B01J2219/00614—Delimitation of the attachment areas
    • B01J2219/00617—Delimitation of the attachment areas by chemical means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00583—Features relative to the processes being carried out
    • B01J2219/00603—Making arrays on substantially continuous surfaces
    • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
    • B01J2219/00623—Immobilisation or binding
    • B01J2219/00626—Covalent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00583—Features relative to the processes being carried out
    • B01J2219/00603—Making arrays on substantially continuous surfaces
    • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
    • B01J2219/00623—Immobilisation or binding
    • B01J2219/0063—Other, e.g. van der Waals forces, hydrogen bonding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00583—Features relative to the processes being carried out
    • B01J2219/00603—Making arrays on substantially continuous surfaces
    • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
    • B01J2219/00632—Introduction of reactive groups to the surface
    • B01J2219/00637—Introduction of reactive groups to the surface by coating it with another layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00583—Features relative to the processes being carried out
    • B01J2219/00603—Making arrays on substantially continuous surfaces
    • B01J2219/00653—Making arrays on substantially continuous surfaces the compounds being bound to electrodes embedded in or on the solid supports
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00583—Features relative to the processes being carried out
    • B01J2219/00603—Making arrays on substantially continuous surfaces
    • B01J2219/00659—Two-dimensional arrays
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00718—Type of compounds synthesised
    • B01J2219/0072—Organic compounds
    • B01J2219/00722—Nucleotides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00718—Type of compounds synthesised
    • B01J2219/0072—Organic compounds
    • B01J2219/00725—Peptides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
    • B01J2219/00718—Type of compounds synthesised
    • B01J2219/0072—Organic compounds
    • B01J2219/0074—Biological products
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
    • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
    • C12Q1/68—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving nucleic acids
    • C12Q1/6813—Hybridisation assays
    • C12Q1/6816—Hybridisation assays characterised by the detection means
    • C12Q1/6825—Nucleic acid detection involving sensors
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
    • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
    • C12Q1/68—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving nucleic acids
    • C12Q1/6813—Hybridisation assays
    • C12Q1/6834—Enzymatic or biochemical coupling of nucleic acids to a solid phase
    • C—CHEMISTRY; METALLURGY
    • C40—COMBINATORIAL TECHNOLOGY
    • C40B—COMBINATORIAL CHEMISTRY; LIBRARIES, e.g. CHEMICAL LIBRARIES
    • C40B40/00—Libraries per se, e.g. arrays, mixtures
    • C40B40/04—Libraries containing only organic compounds
    • C40B40/06—Libraries containing nucleotides or polynucleotides, or derivatives thereof
    • C—CHEMISTRY; METALLURGY
    • C40—COMBINATORIAL TECHNOLOGY
    • C40B—COMBINATORIAL CHEMISTRY; LIBRARIES, e.g. CHEMICAL LIBRARIES
    • C40B40/00—Libraries per se, e.g. arrays, mixtures
    • C40B40/04—Libraries containing only organic compounds
    • C40B40/10—Libraries containing peptides or polypeptides, or derivatives thereof

Definitions

  • Substrate as a carrier for ligates
  • the invention relates to a substrate for use as a carrier for ligates.
  • dynamic ranks of a sensor means the area in which the sensor reproducibly and specifically reacts to changes in the concentration of a particular analyte.
  • the “dynamic ranks” of a sensor is generally about a factor of 10 to 100 in Analyte concentration and is limited to small concentrations by the sensitivity of the detection method. For high concentrations, the sensor becomes saturated from a certain range, so that a further increase in the analyte concentration does not cause a signal change.
  • the object of the invention is to provide a sensor which makes it possible to detect the concentration fluctuations of constituents of an analyte liquid in parallel, which constituents can be present in the test substance in concentrations that differ by orders of magnitude.
  • characteristic parameters of the active areas of the sensor surface such as occupancy parameters e.g. the geometric area of the test sites or their coverage with ligates.
  • the characteristic occupancy parameter defines the number of the respective ligates on the sensor surface and thus also the number of association events for a given analyte concentration via the association constant.
  • Fluorophore chemical compound that is able to emit a longer-wave (red-shifted) fluorescent light when excited with light.
  • Fluorophores fluorescent dyes
  • UV ultraviolet
  • VIS visible
  • IR infrared
  • the absorption and emission maxima are typically shifted from each other by 15 to 40 nm (Stokes shift).
  • Ligand Term for molecules that are specifically bound by the ligate examples are substrates, cofactors or coenzymes of a protein (enzyme), antibodies (as ligand an antigen), antigens (as ligand of an antibody), receptors (as ligand of a hormone), hormones (as ligand of a receptor) or nucleic acid oligomers (as ligand of the complementary nucleic acid oligomers).
  • Ligate Term for (macro) molecule with specific recognition and binding sites for the formation of a complex with a ligand examples include substrates, cofactors or coenzymes of a protein (enzyme), antibodies (as ligate of an antigen), antigens (as ligate of an antibody), receptors (as ligate of a hormone), hormones (as ligate of a receptor) ) or nucleic acid oligomers (as a ligate of the complementary nucleic acid oligomers).
  • Probe Biomolecules applied to the sensor surface that can specifically bind one or more molecules from the test substance (targets).
  • the chains are alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl or heteroalkynyl.
  • Preferred spacers are those of chain length 1-20, in particular chain length 1-14, the chain length being the shortest continuous connection between the structures to be connected.
  • the test site each carry one or more types of probe molecules, each of which can specifically bind one or more molecules of a test substance.
  • the size of these areas and their surface coverage with probes can be optimized to the order of magnitude of the target concentration.
  • Target molecules in the test substance that can bind specifically to one or more biomolecules on the sensor surface (probes).
  • These spacers can in turn be bound to various reactive groups which are naturally present on the nucleic acid oligomer or are attached to it by modification.
  • "N" is any integer, in particular a number between 1 and 20.
  • the spacer for connecting the disulfide function to the nucleic acid oligomer can each have a different chain length (shortest continuous connection between disulfide function and nucleic acid oligomer), in particular any chain length between 1 and 14. These spacers can in turn be connected to different ones naturally existing on the nucleic acid oligomer or attached to it by modification attached reactive groups.
  • the placeholder "n” is any integer, in particular a number between 1 and 20.
  • oligo-spacer-SS- Two identical or different nucleic acid oligomers, spacer oligo, which are connected to one another via a disulfide bridge, the disulfide bridge being connected to the nucleic acid oligomers via any two spacers and the two spacers having a different chain length (shortest continuous connection between disulfide bridge and the respective nucleic acid oligomer), in particular any chain length between 1 and 14.
  • These spacers can in turn be bound to various reactive groups that are naturally present on the nucleic acid oligomer or are attached to them by modification.
  • PNA Peptide nucleic acid synthetic DNA or RNA in which the sugar-phosphate unit is replaced by an amino acid.
  • synthetic DNA or RNA synthetic DNA or RNA in which the sugar-phosphate unit is replaced by an amino acid.
  • the sugar-phosphate unit is replaced by the -NH- (CH 2 ) 2 -N (COCH 2 base) -CH 2 CO unit hybridizes PNA with DNA).
  • Nucleic acid At least two covalently linked nucleotides or at least two covalently linked pyrimidine (e.g. cytosine, thymine or uracil) or purine bases (e.g. adenine or guanine).
  • the term nucleic acid refers to any "backbone" of the covalently linked pyrimidine or purine bases, such as e.g. on the sugar-phosphate backbone of the DNA, cDNA or RNA, on a peptide backbone of the PNA or on analogous structures (e.g. phosphoramide, thio-phosphate or dithio-phosphate backbone).
  • An essential feature of a nucleic acid in the sense of the present invention is the sequence-specific binding of naturally occurring cDNA or RNA.
  • Nucleic acid - nucleic acid of unspecified base length e.g. oligomeric nucleic acid octamer: a nucleic acid with any backbone in which 8 pyrimidine or purine bases are covalently bound to one another.
  • Oligomer equivalent to nucleic acid oligomer Oligomer equivalent to nucleic acid oligomer.
  • Oligonucleotide equivalent to oligomer or nucleic acid oligomer e.g. a DNA, PNA or RNA fragment of unspecified base length.
  • Oligo Abbreviation for oligonucleotide Oligo Abbreviation for oligonucleotide.
  • the present invention relates to a substrate for use as a carrier for ligates in a method for the detection of ligate-ligand association events.
  • Test sites which have ligates bound to the surface are arranged on the substrate. At least two types of test sites are provided, the individual test sites being occupied with different types of ligates. These different types of ligates each detect complementary types of ligands which are present in an analyte solution in different concentration ranges.
  • the test sites have a characteristic occupancy parameter, so that the ligands can be detected in the concentration range in which the respective ligand is present in the analyte solution.
  • a sensor with a given number of specific coupling points reaches a saturation value from a certain analyte concentration in the test substance, so that a further increase in the concentration can no longer be detected.
  • This can theoretically be described with first-order binding kinetics for the binding of a probe S on the sensor surface and a target T in the test substance to form a surface complex ST with an association constant K:
  • the present invention provides a sensor with a "dynamic ranks" optimized with regard to the analysis of analyte liquids which contain analytes in very different concentrations.
  • the present invention is based on the idea that by optimizing the "dynamic range" of a sensor, changes in the concentrations of constituents of a liquid test substance can also be detected in parallel if the initial concentrations of these constituents vary by many orders of magnitude.
  • the substrate of the invention is preferably used as a carrier of biomolecules in a method for the electrochemical or fluorescence spectroscopic detection of components of an electrolyte solution.
  • the substrate according to the invention can also be used in an electrochemical or fluorescence spectroscopic method for the detection of biomolecules.
  • the present invention describes a sensor with spatially limited areas of different probe molecules (spots), each of which can specifically bind one or more target molecules from a test substance.
  • the size and / or surface coverage of the probes (characteristic coverage parameters of the substrate) of the spots of the invention are optimized for the concentration ranges of the corresponding targets to be detected in such a way that the proportion of binding events of all spots for, for example, the non-pathogenic state is independent of the actual concentration of the spots Targets is roughly the same. This leaves the specific "dynamic ranks" of a sensor normalize to this "initial state".
  • the advantage of this method lies in the adjusted sensitivity of all spots with regard to the changes in concentration of the corresponding targets to be detected, regardless of their initial concentration.
  • the sensor is thus optimized for the “tolerable” concentration range between the “permitted”, non-pathogenic value and the “critical”, pathogenic value of each analyte.
  • the composition of the analyte pool of a healthy organism is generally the rule sufficiently known that the present method can be used to provide evidence of a disease (exceeding the "critical" concentration value of an analyte) on the basis of changes in individual analytes.
  • ligands are preferably detected which are present in the analyte solution in concentration ranges whose mean values differ by at least a factor of 10.
  • the mean values of the concentration ranges in which they are present in the analyte solution differ by at least a factor of 100, particularly preferably by at least a factor of 1000, very particularly preferably by at least a factor of 10,000.
  • the present invention also includes the use of the substrates in methods for the detection of ligate-ligand association events.
  • the substrates can be used in particular in fluorescence spectroscopic and electrochemical detection methods.
  • Chronoamperometry (CA), chronocoulometry (CC), linear sweep voltammetry (LSV), cyclic voltammetry (CSV),retemating current voltammetry (ACV), voltammetry techniques with different pulse shapes, in particular square wave voltammetry (SWV), differential pulse voltammetry are used as electrochemical detection methods (DPV) or Normal Pulse Voltammetry (NPV), AC Impedance Spectroscopy, Chronopotentiometry and Cyclic Chronopotentiometry in question.
  • CA Chronoamperometry
  • CC chronocoulometry
  • LSV linear sweep voltammetry
  • CSV cyclic voltammetry
  • ACCV alternating current voltammetry
  • SWV square wave voltammetry
  • DUV electrochemical detection methods
  • NPV Normal Pulse Voltammetry
  • AC Impedance Spectroscopy
  • the characteristic occupancy parameter of the substrate is the size of the area of the individual test sites.
  • the area of the test sites preferably differs by at least a factor of 10, particularly preferably by at least a factor of 100, particularly preferably by at least a factor of 1000 and very particularly preferably by at least a factor of 10000.
  • substrates which have test site areas between 1 ⁇ m 2 and 1 mm 2 Preference is given to substrates which have test site areas between 1 ⁇ m 2 and 1 mm 2 . Substrates which have test site areas between 10 ⁇ m 2 and 100000 ⁇ m 2 are particularly preferred.
  • solid bodies with a freely accessible surface that can be functionalized with biomolecules and wetted with a liquid test substance are suitable as sensor substrates.
  • Solid substrates include plastics as well as metals, semiconductors, glasses, composites or porous materials.
  • the term surface is independent of the spatial dimensions of the surface. The surface of the sensor must be divisible into separate areas. This can be achieved by structuring the solid-state substrate into active and inactive areas or by partially functionalizing its homogeneous surface.
  • the structuring of the solid state substrates into active and inactive areas can be e.g. by lithography, vacuum deposition, electrochemical deposition, doping or laser treatment.
  • the structuring on homogeneous substrates can be achieved by applying and structuring passivation layers.
  • any material that forms a closed layer on a surface and thus separates the substrate surface from the environment is suitable as a passivation layer. At a later time the material can e.g. can be removed in its entire thickness without residue by laser ablation at the desired locations.
  • micro-contact printing ⁇ CP mico-contact printing
  • Whitesides 1994 A. Kumar, G.M. Whitesides, Science, 1994, 263, 60
  • a microstructured stamp is wetted with a liquid, then brought into direct contact with the substrate to be processed, and a lateral chemical structure is thus imprinted on the surface.
  • electrically conductive materials such as platinum, palladium, gold, cadmium, mercury, nickel, zinc, carbon, silver, copper, iron, lead, aluminum, manganese, any doped or undoped semiconductors and binary or ternary connections are used as surfaces of the sensor substrates.
  • electrically conductive materials such as platinum, palladium, gold, cadmium, mercury, nickel, zinc, carbon, silver, copper, iron, lead, aluminum, manganese, any doped or undoped semiconductors and binary or ternary connections are used as surfaces of the sensor substrates.
  • homogeneous electrically conductive surfaces can be structured or conductive materials can be applied to spatially separated areas of a non-conductive substrate, such as glass or plastic, in any thickness.
  • insulating carrier plates are used as sensor substrates, which are expediently rigid carrier plates on one side, rigid carrier plates on both sides or rigid multilayer carrier plates.
  • the insulating carrier plate can be a one-sided or double-sided flexible carrier plate, in particular made of a polyimide film, or a rigid-flexible carrier plate. It advantageously consists of a base material that is selected from the group BT (bismaleimide triazine resin with quartz glass), CE (cyanate ester with quartz glass), CEM1 (hard paper core with FR4 outer layers), CEM3 (glass fleece core with FR4 outer layers), FR2 ( Phenolic resin paper), FR3 (hard paper), FR4 (epoxy glass hard fabric), FR5 (epoxy glass hard fabric with cross-linked resin system), PD (polyimide resin with aramid reinforcement), PTFE (polytetrafluoroethylene with glass or ceramic), CHn (highly cross-linked hydrocarbons with ceramic) and glass ,
  • BT bismaleimide triazine resin with quartz glass
  • CE cyanate ester with quartz glass
  • CEM1 hard paper core with FR4 outer layers
  • CEM3
  • carrier plates have a certain number of conductor tracks with a gold surface, which are coated with a solder resist layer as a passivation.
  • laser gold ablation is used to burn free gold spots into the lacquer for later functionalization.
  • spots of any size and geometry can be written in the lacquer, whereby only the width of the conductor tracks represents a limit.
  • laser ablation not only removes the lacquer layer at desired points, but also ensures that the surface of the gold is temporarily melted and the pores are reduced by melting it briefly. By melting the substrates, a few gold layers are additionally ablated from the surface, thus removing impurities.
  • the conductor track substrates just described are suitable both for electrochemical measurement methods and for fluorescence spectroscopy. Functionalization of the active areas with ligates
  • the active areas of the sensor are functionalized with ligates, which act as probes for the ligands present in the test substance.
  • ligates which act as probes for the ligands present in the test substance.
  • all types of ligates are suitable for examining analyte liquids for the presence of their specific ligands. Molecules that specifically interact with a ligand to form a complex are referred to as ligates.
  • ligates in the sense of the present document are substrates, cofactors or coenzymes as complex binding partners of a protein (enzyme), antibodies (as complex binding partners of an antigen), antigens (as complex binding partners of an antibody), receptors (as complex binding partners of a hormone), hormones (as complex binding partners of a receptor), nucleic acid oligomers (as complex binding partner of the complementary nucleic acid oligomer) or metal complexes.
  • the number of probes on the sensor surface scales linearly with the surface, for example the application of probe monolayers under conditions which enable an occupancy of less than the densest packing.
  • volume methods for immobilizing the probes, for example via functionalized polymers, are also conceivable as long as the number of probes continues to scale with the area.
  • the free substrate sites are preferably wetted with modified nucleic acid oligomers in aqueous solution.
  • the nucleic acid oligomer which is to be applied to the free surface is modified via a covalently attached spacer of any composition and chain length with one or more reactive groups, these reactive groups preferably being located near one end of the nucleic acid oligomer.
  • the reactive groups are preferably groups that can react directly with the unmodified surface.
  • nucleic acid oligomers of the general formula (nx HS spacer) oligo, (nx RSS spacer) oligo or oligo spacer SS -Spacer-oligo, which react with a gold surface to form gold-sulfur bonds, (ii) nucleic acid oligomers with amines that attach to platinum or silicon surfaces by chemical or physical sorption and (iii) nucleic acid oligomers with silanes that form a covalent bond with oxidic surfaces. With these types of attachment of nucleic acid oligomers, deposits of less than the densest packing are generally realized, so that there is sufficient space on the surface for later hybridization.
  • HS spacer thiol
  • SS disulfide
  • the molecule can also be modified with an electrochemical label if necessary via a further spacer of any composition and chain length, if the functionalization of the free substrate sites and the subsequent hybridization using electrochemical
  • Oligonucleotides with a redox label can be used electrochemical methods to investigate the hybridization events, if the
  • Target molecules are provided with a redox label.
  • Another electrochemical detection variant is a displacement assay, in which short-chain signal oligomers are also bound to the unlabeled probe oligomers
  • Redox labels of unlabeled target oligomers of the complementary sequence are displaced.
  • Transition metal complexes in particular those of copper, iron, ruthenium, osmium or titanium with ligands such as pyridine, 4,7-dimethylphenanthroline, 9,10-phenanthrenequinone diimine, can be used as redox labels of the ligates or ligands, Porphyrins and substituted porphyrin derivatives can be used.
  • riboflavin of quinones such as pyrrolloquinoline quinone, ubiquinone, anthraquinone, naphthoquinone or menaquinone or derivatives thereof, of metallocenes and metallocene derivatives such as ferrocenes and ferrocene derivatives, cobaltocenes and cobaltocene derivatives, of porphyrins, methylene blue, hydroquinone derivatives, daaminomycin derivatives Derivatives (para or ortho dihydroxy benzene derivatives, para or ortho dihydroxy anthraquinone derivatives, para or ortho dihydroxy naphthoquinone derivatives) and similar compounds are possible.
  • quinones such as pyrrolloquinoline quinone, ubiquinone, anthraquinone, naphthoquinone or menaquinone or derivatives thereof
  • metallocenes and metallocene derivatives such as ferrocenes and ferrocene derivative
  • ligates or ligands can be given a fluorophore as a second functionalization via a further spacer of any composition and chain length if the functionalization of the free substrate sites and the subsequent hybridization are to be examined with the aid of optical methods.
  • fluorescence spectroscopy can also be performed with a fluorophore on the target molecules and unlabeled probes.
  • fluorescent dyes such as e.g. Texas Red®, rhodamine dyes, Cy3 TM, Cy5 TM, fluorescein etc. (cf. Fluka, Amersham and Molecular Probes catalog) can be used.
  • Two techniques are particularly suitable for the functionalization of the exposed substrate sites.
  • small volumes are selectively applied to the spots of the substrate using a commercially available spotter, each spot being able to be functionalized with different molecules.
  • all exposed spots can be functionalized with the same probe molecules, for example by immersing the substrate in the probe liquid or by wetting the entire substrate. Varying the surface concentration of the ligates
  • the number of probes on the sensor surface can also be set without varying the active spot size. This means that different amounts of probe molecules can be realized on spots of the same size with just one sensor design.
  • a particularly preferred embodiment of the present invention is therefore substrates whose characteristic occupancy parameter is the occupancy density of the test sites with ligates.
  • the occupancy densities of the test sites with ligates particularly preferably differ by at least a factor of 10, particularly preferably by at least a factor of 100 and very particularly preferably by at least a factor of 1000.
  • the assignment can e.g. the incubation time, the number of coupling groups per molecule, the molarity of the loading buffer or the concentration of the molecules in the incubation solution.
  • the surface coverage is set using a coadsorbate.
  • a suitable coadsorbate is added to the incubation solution of the probe molecules in a certain concentration and brought into contact with the sensor surface, or the coadsorbate is applied in a second coating step after the functionalization with the probes.
  • the coadsorbate preferably has the same coupling group as the probe molecule, thus occupies part of the active surface and ensures a reduced surface coverage of the probe.
  • the surface coverage can be adjusted via the concentration of the coadsorbate in the respective incubation solution.
  • short-chain thiols of the general structure SH- (CH 2 ) n -X are particularly preferred, where X can be any head group.
  • Fig. 1 Theoretical curves of the relative proportion of binding events ([TS] / S 0 ) for different target concentrations.
  • concentration of the probes on the sensor surface is normalized to the association constant of the binding.
  • Fig. 2 Schematic image of a section of the sensor substrates based on circuit board technology, a) top view of the conductor track substrate with free substrate locations of different active area and geometry, b) cross section through a substrate with 3 identical electrode spots.
  • the gold sites of the substrate exposed by laser ablation are functionalized with double-modified nucleic acid oligomers, which have a thioi group at one end for binding to the gold surface and at the other end have an electrochemical label (e.g. osmium complexes).
  • the desired number of probes on the sensor surface is set either via the electrode size or by using a short-chain thiol of a certain concentration as a coadsorbate.
  • the nucleic acid oligomers of the test liquid also have an electrochemical label (eg ferrocene derivatives), so that both the assignment with the nucleic acid oligomers and the hybridization efficiency can be determined using electrochemical methods.
  • a preferred measurement method for analyzing occupancy and hybridization efficiency is AC (alternating current) voltammetry. From the ACV current at the redox potential of the label, according to O'Connor et al. (J. Electroanal. Chem., 466, 1999, 197-202) calculate the number of labels involved. The experiments can thus be evaluated quantitatively.
  • Example 1 PCB substrates.
  • FIG. 2a shows a section of this conductor track picture. The detail shows 4 of the 48 working electrodes (20A to 20D) and part of the counter electrode 28.
  • the entire conductor pattern is covered with a 15 ⁇ m to 20 ⁇ m thick passivation layer 22 (FIG. 2 b) made of structurable, optically curable lacquer (2-component solder resist, Elpemer GL 2467 SM-DG, from Peters).
  • Recesses 24, 24A to 24D are made in the passivation layer by high-energy pulses from an excimer laser and are used to hold the biomolecules 26.
  • a passivation layer with a thickness of 15 ⁇ m to 20 ⁇ m, you need to remove the lacquer and melt it for a short time
  • the melting of the surface leads to the closure of surface pores of the gold layer, to a reduction in the surface roughness and, by ablation, fewer gold layers to the removal of surface impurities.
  • the laser irradiation of the substrate can take place directly or via an optic or mask and enables recesses of any size and geometry.
  • FIG. 2b shows a section through a conductor track substrate with 3 identical spots.
  • Each of the conductor tracks 20 consists of a copper core 14 which is continuously covered by a nickel barrier layer 16 and a gold layer 18.
  • the copper core has a thickness of approximately 28 ⁇ m. It represents an inexpensive and highly conductive basic component of the conductor tracks.
  • the base copper core is coated with a 6 ⁇ m thick, continuous nickel layer as a diffusion barrier. A 2 ⁇ m thick gold layer is applied to this nickel layer.
  • the conductor tracks of the exemplary embodiment are approximately 150 ⁇ m wide and are arranged on the carrier plate at a distance of approximately 200 ⁇ m (center-center).
  • the working electrodes, the counter electrode and a reference electrode, if provided, are each connected to connection contact surfaces (not shown) of the electrical substrate for contacting.
  • the conductor tracks have circular recesses with diameters of 10 ⁇ m, 30 ⁇ m, 100 ⁇ m and rectangular recesses with the dimensions 100 ⁇ m ⁇ 700 ⁇ m (cf. 24A to 24D in FIG. 2a). These recesses thus have areas of 78.5 ⁇ m 2 , 706.5 ⁇ m 2 , 7850 ⁇ m 2 or 70000 ⁇ m 2 , so that the active area of the electrodes is varied by a factor of 1000.
  • Example 2 Functionalization of the spots of the substrate with nucleic acid oligomers.
  • the free substrate sites of various sizes described in Example 1 are e.g. functionalized with the nucleic acid oligomers via a spotting method.
  • the oligonucleotides are synthesized in an automatic oligonucleotide synthesizer (Expedite 8909; ABI 384 DNA / RNA synthesizer) in accordance with the synthesis protocols recommended by the manufacturer for a 1.0 ⁇ mol synthesis.
  • the oxidation steps are carried out with a 0.02 mol / l iodine solution in order to avoid oxidative cleavage of the disulfide bridge.
  • Modifications to the 5'-position of the oligonucleotides are carried out with a coupling step which is extended to 5 min.
  • the amino modifier C2 dT (Glen Research 10-1037) is incorporated into the sequences according to the respective standard protocol.
  • the coupling efficiencies are determined online during the synthesis via the DMT cation concentration photometrically or conductometrically.
  • the oligonucleotides are deprotected with concentrated ammonia (30%) at 37 ° C for 16 h.
  • the oligonucleotides are purified using RP-HPL chromatography according to standard protocols (eluent: 0.1 mol / l triethylammonium acetate buffer, acetonitrile), and the characterization is carried out using MALDI-TOF MS.
  • the amine-modified oligonucleotides are coupled to the activated redox labels (e.g. osmium complexes) in accordance with the conditions known to the person skilled in the art. The coupling can take place both before and after the oligonucleotides have been bound to the surface.
  • the substrates from Example 1 are, for example, modified with double-modified 20 bp single-strand oligonucleotide of the sequence 5'-AGC GGA TAA CAC AGT CAC CT-3 '(modification one: the phosphate group of the 3' end is with (HO- (CH 2 ) 2 -S) 2 esterified to P- O- (CH 2 ) 2 -SS- (CH 2 ) 2 -OH
  • Modification two: at the amino-modified 5 'end is the osmium complex [Os (bipy) 2 Cl imidazole acrylic acid] according to the respective standard protocol) as a 5x10 "5 molar solution in buffer (Phosphate buffer, 0.5 molar in water, pH 7 with 0.05 vol% SDS) applied using a spotter (Carthesian) and incubated for 2 - 24 h.
  • the disulfide spacer PO- (CH 2 ) 2 -SS- (CH 2 ) 2 -OH of the oligonucleotide is cleaved homolytically.
  • the spacer forms a covalent Au-S bond with the Au atoms on the surface, which leads to a 1: 1 coadsorption of the ss-oligonucleotide and the split off 2-hydroxy-mercaptoethanol.
  • the single-strand can also be hybridized with its complementary strand.
  • Split-pin needles (Arraylt chipmarker pins from TeleChem) are used for the assignment with the spotter from Cartesian Technologies (MicroSys PA), which have a loading volume of 0.2 to 0.6 ⁇ l and deliver volumes of about 1 nl per wetting process.
  • the contact area of these needles has a diameter of approximately 130 ⁇ m and is therefore significantly larger than the areas of the substrate exposed during laser ablation.
  • the needle is positioned over the substrate with an accuracy of 10 ⁇ m at a humidity of around 70 - 80%. The drop is released when the tip comes into contact with the passivation layer and there is no direct contact with the substrate (“pseudo-contact printing”).
  • Example 3 Variation of the surface coverage by coadsorbates.
  • the occupancy density of a spot with nucleic acid oligomers can be reduced in a controlled manner by coadsorption with thiols, in order to increase the relative proportion of binding events with the target concentration and electrode size remaining the same.
  • the incubation solution consists of the nucleic acid oligomers (analogous to Example 2) with an additional between about 10 "5 to 10 '1 molar propanethiol.
  • This free propanethiol which is present at the same time, is co-adsorbed by forming an Au-S bond and thus takes up space on the sensor surface
  • the propanethiol (10 "5 to 10 " 1 molar in 500 mmol / l phosphate buffer) is applied in a second incubation step (30 min to 12 h) after the functionalization of the sensor surface with nucleic acid oligomers.
  • propanethiol as a coadsorbate can reduce the surface coverage density of the nucleic acid oligomers in both variants by up to a factor of 10.
  • Example 4 Varying the surface occupancy using occupancy parameters.
  • the surface coverage density of the sensor spots can also be adjusted by varying selected occupancy parameters when functionalizing with nucleic acid oligomers.
  • the occupancy density increases by a factor of 5.
  • concentration of the incubation buffer is increased from 10 mmol / l to 500 mmol / l at a probe concentration of 30 ⁇ mol / l.
  • Example 5 Hybridization with complementary nucleic acid oligomers.
  • a substrate with 48 working electrodes is produced as described in Example 1 with active areas of different sizes.
  • groups of 12 electrodes each, circular holes with a diameter of 10 ⁇ m (spot group 1), 30 ⁇ m (spot group 2) or 100 ⁇ m (spot group 3) and a rectangular profile with 100 ⁇ m x 700 ⁇ m ( Spot group 4) burned.
  • the individual spot groups therefore have areas of 78.5 ⁇ m 2 , 706.5 ⁇ m 2 , 7850 ⁇ m 2 or 70000 ⁇ m 2 , so that the area is varied by a factor of around 1000.
  • the working electrodes of a spot group are each functionalized with double-modified nucleic acid oligomers (probes) of a certain sequence (S1 to S4) analogously to Example 2.
  • the surface coverage density with nucleic acid oligomers can be calculated from the redox current at the potential of the osmium complex. In the present case, the result is 5 x 10 "1 mol / cm 2 .
  • the working electrodes are brought into contact with complementary, ferrocene-modified nucleic acid oligomers in a post-loading step for 30 minutes with a 1 mmol / l solution of propanethiol before hybridization.
  • the spaces between the nucleic acid oligomers are rendered hydrophobic. This shifts the redox potential of ferrocene to more positive values, resulting in better separation from the osmium potential.
  • the four different target nucleic acid oligomers are synthesized analogously to Example 2 but without a thiol modification at the 3 'end.
  • the target nucleic acid oligomers have a sequence (T1 to T4) which is complementary to a probe nucleic acid oligomer.
  • T1 to T4 the amino-modified nucleic acid oligomers are coupled at the 5 'end with ferrocene acetic acid (FcAc) in accordance with the respective standard protocol.
  • FcAc ferrocene acetic acid
  • the measurement data show a second redox peak, the ratio of the peak currents of the osmium label and the ferrocene label corresponding to the hybridization efficiency of the experiment.
  • the measurement data of the hybridization from FIG. 3 show an electrode close to saturation with a hybridization efficiency of over 90%.
  • the working electrodes with the sizes adapted to the concentrations of the respective targets all show the same hybridization efficiencies of approximately 30-40%.
  • Example 6 Diagnostic chip.
  • vaginal smear which is examined for HPV, E-Coli and lactobacilli, among others.
  • a sample is taken with the aid of standardized swabs, which is then treated using standardized methods in order to obtain the RNA of the bacteria present and the double-stranded DNA of the viruses.
  • bacteria or particle numbers up to a certain limit are classified as harmless: for HPV this is 100 particles, for E-coli 100 germs and for lactobacilli 10000 germs of all relevant lactobacilli.
  • a sensor chip according to the invention for the above application has three different spot sizes, which are functionalized with probe polynucleotides specific for the respective disease targets.
  • Spots with an area of 1 ⁇ m 2 are used to detect the HPV-DNA in the range of 10 2 to 10 4 molecules in the test substance, while for the E-Coli RNA in the range of 10 6 to 10 8 molecules (corresponding to 10 2 up to 10 4 germs) areas of 10 4 ⁇ m 2 and for the lactobacillus RNA in the range of 10 8 to 10 10 molecules (corresponding to 10 4 to 10 6 germs) areas of 10 6 ⁇ m 2 are used.
  • the choice of the electrode sizes ensures that the sensor for the respective area allows quantitative measurements from the critical target concentrations of the different pathogens and thus a parallel diagnosis of all diseases can be made.

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Abstract

The invention relates to a substrate used as a ligate carrier for a method for detecting a ligate-ligand association. Test spots (24) to which surface the legates (26) are bound are disposed on said carrier; at least two test spots are provided. According to said invention, different types of test spots (24) are allocated to different kinds of ligates (26), thereby making it possible to detect different kinds of complementary ligands. The ligands are present in an analyte solution in different concentration ranges and the test spots (24) have a characteristic occupation parameter which makes it possible to detect the ligands in different concentration ranges.

Description

Substrat als Träger von Ligaten Substrate as a carrier for ligates
Technisches GebietTechnical field
Die Erfindung betrifft ein Substrat zum Einsatz als Träger von Ligaten.The invention relates to a substrate for use as a carrier for ligates.
Stand der TechnikState of the art
Im Bereich der Biowissenschaften, der Medizintechnik und der Sensorik wurden speziell in den letzten Jahren viele Sensoren und Verfahren für die Forschungsgebiete „Genomics" und „Proteomics" entwickelt. Für das Verständnis von Organismen ist die Analyse ihrer Gene bzw. ihres Proteinsatzes unerlässlich. Der Mensch besitzt z.B. in etwa 30000 - 50000 Gene und etwa 500000 verschiedene Proteine. Um diesen enormen Informationsgehalt detektieren zu können, bedarf es Sensoren mit einem hohen Grad an Parallelisierung und intelligente Auswertealgorithmen. Eine entscheidende Limitierung in Bezug auf die Qualität eines Sensors stellt der so genannte „dynamic ränge" des Sensors dar.In the field of life sciences, medical technology and sensor technology, many sensors and processes for the research areas "Genomics" and "Proteomics" have been developed, especially in recent years. In order to understand organisms, the analysis of their genes or their protein set is essential. Man has e.g. in about 30,000 - 50,000 genes and about 500,000 different proteins. To be able to detect this enormous amount of information, sensors with a high degree of parallelization and intelligent evaluation algorithms are required. A crucial limitation with regard to the quality of a sensor is the so-called "dynamic ranks" of the sensor.
Unter dem Begriff „dynamic ränge" eines Sensors versteht man den Bereich, in dem der Sensor auf Änderungen in der Konzentration eines bestimmten Analyten reproduzierbar und spezifisch reagiert. Der „dynamic ränge" eines Sensors beträgt in der Regel etwa einen Faktor 10 bis 100 in der Analytkonzentration und ist zu kleinen Konzentrationen hin durch die Sensitivität der Nachweismethode begrenzt. Für hohe Konzentrationen tritt der Sensor ab einem gewissen Bereich in Sättigung, so dass eine weitere Erhöhung der Analytkonzentration keine Signaländerung hervorruft.The term "dynamic ranks" of a sensor means the area in which the sensor reproducibly and specifically reacts to changes in the concentration of a particular analyte. The "dynamic ranks" of a sensor is generally about a factor of 10 to 100 in Analyte concentration and is limited to small concentrations by the sensitivity of the detection method. For high concentrations, the sensor becomes saturated from a certain range, so that a further increase in the analyte concentration does not cause a signal change.
Im Bereich der Genexpressionsanalyse von Organismen oder der Identifizierung von Fremdkeimen wie z.B. Viren oder Bakterien in Organismen, wie sie beispielsweise bei einer medizinischen Untersuchung durchgeführt wird, ergibt sich oft die Problemstellung, viele verschiedene Analyten nebeneinander quantitativ analysieren zu müssen. Die Konzentrationen dieser Analyten können aber um viele Größenordnungen schwanken. Bereits im nicht-pathogenen Zustand liegen die Analyten in sehr unterschiedlichen Konzentrationen vor. Die Ausbildung einer pathogenen Wirkung setzt in der Regel erst bei Überschreitung eines Analyt- abhängigen Grenzwertes ein, der ein Vielfaches der tolerablen Grundanalytkonzentration darstellen kann. Solche extrem streuenden Änderungen in den Analytkonzentrationen können von den aus dem Stand der Technik bekannten Sensoren nicht parallel detektiert werden. Vielmehr werden mehrere Sensoren verwendet, die jeweils nur Änderungen der Konzentration einer Gruppe von Analyt-Molekülen detektieren, welche in einer ähnlichen Anfangskonzentration vorliegen.This results in the area of gene expression analysis of organisms or the identification of foreign germs such as viruses or bacteria in organisms, such as is carried out for example in a medical examination often the problem of having to analyze many different analytes side by side quantitatively. The concentrations of these analytes can vary by many orders of magnitude. The analytes are present in very different concentrations even in the non-pathogenic state. The development of a pathogenic effect generally only begins when an analyte-dependent limit value is exceeded, which can represent a multiple of the tolerable basic analyte concentration. Such extremely scattering changes in the analyte concentrations cannot be detected in parallel by the sensors known from the prior art. Rather, several sensors are used, each of which only detects changes in the concentration of a group of analyte molecules which are present in a similar initial concentration.
Darstellung der ErfindungPresentation of the invention
Hier setzt die Erfindung an. Der Erfindung, wie sie in den Ansprüchen gekennzeichnet ist, liegt die Aufgabe zugrunde, einen Sensor bereitzustellen, der es ermöglicht, die Konzentrationsschwankungen von Bestandteilen einer Analytflüssigkeit parallelisiert zu detektieren, wobei diese Bestandteile in um Größenordnungen verschiedenen Konzentrationen in der Testsubstanz vorliegen können.This is where the invention comes in. The object of the invention, as characterized in the claims, is to provide a sensor which makes it possible to detect the concentration fluctuations of constituents of an analyte liquid in parallel, which constituents can be present in the test substance in concentrations that differ by orders of magnitude.
Diese Aufgabe wird erfindungsgemäß durch das Substrat nach Anspruch 1 und die Verwendung des Substrats nach Anspruch 24 gelöst. Weitere vorteilhafte Details, Aspekte und Ausgestaltungen der vorliegenden Erfindung ergeben sich aus den abhängigen Ansprüchen, der Beschreibung, den Figuren und den Beispielen.This object is achieved according to the invention by the substrate according to claim 1 and the use of the substrate according to claim 24. Further advantageous details, aspects and configurations of the present invention result from the dependent claims, the description, the figures and the examples.
Im Rahmen der vorliegenden Erfindung werden die folgenden Abkürzungen und Begriffe benutzt: ACV Altemating current voitammetryThe following abbreviations and terms are used in the context of the present invention: ACV Altemating current voitammetry
dynamic ränge Bereich eines Sensors, in dem er auf Änderungen in der Konzentration eines bestimmten Analyten reproduzierbar und spezifisch reagiert.dynamic range Range of a sensor in which it reacts reproducibly and specifically to changes in the concentration of a certain analyte.
charakteristischer Parameter der aktiven Bereiche der Sensoroberfläche, wie Belegungsparameter z.B. die geometrische Fläche der Test-Sites oder ihre Belegungsdichte mit Ligaten. Der charakteristische Belegungsparameter definiert die Anzahl der jeweiligen Ligaten auf der Sensoroberfläche und somit über die Assoziationskonstante auch die Anzahl der Assoziationsereignisse bei gegebener Analytkonzentration.characteristic parameters of the active areas of the sensor surface, such as occupancy parameters e.g. the geometric area of the test sites or their coverage with ligates. The characteristic occupancy parameter defines the number of the respective ligates on the sensor surface and thus also the number of association events for a given analyte concentration via the association constant.
FcAc Ferrocen Acetic acid (Ferrocen Essigsäure)FcAc Ferrocene Acetic Acid
Fluorophor chemische Verbindung (chemische Substanz), die in der Lage ist, bei Anregung mit Licht ein längerwelliges (rotverschobenes) Fluoreszenzlicht abzugeben. Fluorophore (Fluoreszenzfarb-stoffe) können Licht in einem Wellenlängenbereich vom ultravioletten (UV) über den sichtbaren (VIS) bis hin zum infraroten (IR) Bereich absorbieren. Die Absorptions- und Emissionsmaxima sind typischerweise um 15 bis 40 nm gegeneinander verschoben (Stokes-Shift).Fluorophore chemical compound (chemical substance) that is able to emit a longer-wave (red-shifted) fluorescent light when excited with light. Fluorophores (fluorescent dyes) can absorb light in a wavelength range from ultraviolet (UV) through the visible (VIS) to the infrared (IR) range. The absorption and emission maxima are typically shifted from each other by 15 to 40 nm (Stokes shift).
Laser-Ablation Partielles oder vollständiges Entfernen von organischen oder anorganischen Passivierungsschichten, aber auch das Entfernen von Verunreinigungen auf einem Substrat durch Einstrahlung von Laserlicht.Laser ablation Partial or complete removal of organic or inorganic passivation layers, but also the removal of contaminants on a substrate by exposure to laser light.
Ligand Bezeichnung für Moleküle, die vom Ligaten spezifisch gebunden werden; Beispiele von Liganden im Sinne der vorliegenden Erfindung sind Substrate, Cofaktoren oder Coenzyme eines Proteins (Enzyms), Antikörper (als Ligand eines Antigens), Antigene (als Ligand eines Antikörpers), Rezeptoren (als Ligand eines Hormons), Hormone (als Ligand eines Rezeptors) oder Nukleinsäure-Oligomere (als Ligand der komplementären Nukleinsäure-Oligomere).Ligand Term for molecules that are specifically bound by the ligate; Examples of ligands in the context of the present invention are substrates, cofactors or coenzymes of a protein (enzyme), antibodies (as ligand an antigen), antigens (as ligand of an antibody), receptors (as ligand of a hormone), hormones (as ligand of a receptor) or nucleic acid oligomers (as ligand of the complementary nucleic acid oligomers).
Ligat Bezeichnung für (Makro-) Molekül, an dem sich spezifische Erkennungs- und Bindungsstellen für die Ausbildung eines Komplexes mit einem Liganden befinden. Beispiele von Ligaten im Sinne der vorliegenden Erfindung sind Substrate, Cofaktoren oder Coenzyme eines Proteins (Enzyms), Antikörper (als Ligat eines Antigens), Antigene (als Ligat eines Antikörpers), Rezeptoren (als Ligat eines Hormons), Hormone (als Ligat eines Rezeptors) oder Nukleinsäure- Oligomere (als Ligat der komplementären Nukleinsäure- Oligomere).Ligate Term for (macro) molecule with specific recognition and binding sites for the formation of a complex with a ligand. Examples of ligates in the sense of the present invention are substrates, cofactors or coenzymes of a protein (enzyme), antibodies (as ligate of an antigen), antigens (as ligate of an antibody), receptors (as ligate of a hormone), hormones (as ligate of a receptor) ) or nucleic acid oligomers (as a ligate of the complementary nucleic acid oligomers).
μCP Micro-Contact-Printing.μCP micro-contact printing.
Osmium-Komplex [Os(bipy)2 Cl imidazolacrylsäure]Osmium complex [Os (bipy) 2 Cl imidazole acrylic acid]
SDS SodiumdodecylsulfatSDS sodium dodecyl sulfate
Sonde Auf die Sensoroberfläche aufgebrachte Biomoleküle, die spezifisch ein oder mehrere Moleküle aus der Testsubstanz (Targets) binden können.Probe Biomolecules applied to the sensor surface that can specifically bind one or more molecules from the test substance (targets).
Spacer Beliebige molekulare Verbindung zwischen zwei Molekülen bzw. zwischen einem Oberflächenatom,Spacer Any molecular connection between two molecules or between a surface atom,
Oberflächenmolekül oder einer Oberflächenmolekülgruppe und einem anderen Molekül. In der Regel handelt es sich um Alkyl-, Alkenyl-, Alkinyl-, Heteroalkyl-, Heteroalkenyl- oder Heteroalkinyl-Ketten. Bevorzugte Spacer sind solche der Kettenlänge 1 - 20, insbesondere der Kettenlänge 1 - 14, wobei die Kettenlänge die kürzeste durchgehende Verbindung zwischen den zu verbindenden Strukturen darstellt.Surface molecule or a surface molecule group and another molecule. As a rule, the chains are alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl or heteroalkynyl. Preferred spacers are those of chain length 1-20, in particular chain length 1-14, the chain length being the shortest continuous connection between the structures to be connected.
Spot bzw. Räumlich begrenzte Gebiete auf der Sensoroberfläche, die Test-Site je einen oder mehrere Typen von Sonden-Moleküle tragen, die spezifisch je ein oder mehrere Moleküle einer Testsubstanz binden können. Die Größe dieser Bereiche bzw. ihre Oberflächenbelegung mit Sonden lässt sich auf die Größenordnung der Target-Konzentration optimieren.Spot or spatially limited areas on the sensor surface, the test site each carry one or more types of probe molecules, each of which can specifically bind one or more molecules of a test substance. The size of these areas and their surface coverage with probes can be optimized to the order of magnitude of the target concentration.
Target Moleküle in der Testsubstanz, die spezifisch an ein oder mehrere Biomoleküle an der Sensoroberfläche (Sonden) binden können.Target molecules in the test substance that can bind specifically to one or more biomolecules on the sensor surface (probes).
(n x HS-Spacer)- Nukleinsäure-Oligomer, an das n Thiolfunktionen über oligo jeweils einen Spacer angebunden sind, wobei die Spacer jeweils eine unterschiedliche Kettenlänge (kürzeste durchgehende Verbindung zwischen Thiolfunktion und Nukleinsäure-Oligomer) aufweisen können, insbesondere jeweils eine beliebige Kettenlänge zwischen 1 und 14. Diese Spacer können wiederum an verschiedene natürlich am Nukleinsäure-Oligomer vorhandene oder an diesem durch Modifikation angebrachte reaktive Gruppen gebunden sein. Dabei ist „n" eine beliebige ganze Zahl, insbesondere eine Zahl zwischen 1 und 20.(nx HS spacer) - Nucleic acid oligomer, to which n thiol functions are each connected via oligo, a spacer, the spacers each having a different chain length (shortest continuous connection between thiol function and nucleic acid oligomer), in particular any chain length between 1 and 14. These spacers can in turn be bound to various reactive groups which are naturally present on the nucleic acid oligomer or are attached to it by modification. "N" is any integer, in particular a number between 1 and 20.
(n x R-S-S-Spacer)- Nukleinsäure-Oligomer, an das n Disulfidfunktionen über oligo jeweils einen Spacer angebunden sind, wobei ein beliebiger Rest R die Disulfidfunktion absättigt. Der Spacer zur Anbindung der Disulfidfunktion an das Nukleinsäure- Oligomer kann jeweils eine unterschiedliche Kettenlänge (kürzeste durchgehende Verbindung zwischen Disulfidfunktion und Nukleinsäure-Oligomer) aufweisen, insbesondere jeweils eine beliebige Kettenlänge zwischen 1 und 14. Diese Spacer können wiederum an verschiedene natürlich am Nukleinsäure-Oligomer vorhandene oder an diesem durch Modifikation angebrachte reaktive Gruppen gebunden sein. Der Platzhalter „n" ist eine beliebige ganze Zahl, insbesondere eine Zahl zwischen 1 und 20.(nx RSS spacer) - Nucleic acid oligomer to which n disulfide functions are each connected via a spacer via oligo, with any radical R saturating the disulfide function. The spacer for connecting the disulfide function to the nucleic acid oligomer can each have a different chain length (shortest continuous connection between disulfide function and nucleic acid oligomer), in particular any chain length between 1 and 14. These spacers can in turn be connected to different ones naturally existing on the nucleic acid oligomer or attached to it by modification attached reactive groups. The placeholder "n" is any integer, in particular a number between 1 and 20.
oligo-Spacer-S-S- Zwei gleiche oder verschiedene Nukleinsäure-Oligomere, Spacer-oligo die über eine Disulfid-Brücke miteinander verbunden sind, wobei die Disulfidbrücke über zwei beliebige Spacer an die Nukleinsäure-Oligomere angebunden ist und die beiden Spacer eine unterschiedliche Kettenlänge (kürzeste durchgehende Verbindung zwischen Disulfidbrücke und dem jeweiligen Nukleinsäure-Oligomer) aufweisen können, insbesondere jeweils eine beliebige Kettenlänge zwischen 1 und 14. Diese Spacer können wiederum an verschiedene natürlich am Nukleinsäure-Oligomer vorhandene oder an diese durch Modifikation angebrachte reaktive Gruppen gebunden sein.oligo-spacer-SS- Two identical or different nucleic acid oligomers, spacer oligo, which are connected to one another via a disulfide bridge, the disulfide bridge being connected to the nucleic acid oligomers via any two spacers and the two spacers having a different chain length (shortest continuous connection between disulfide bridge and the respective nucleic acid oligomer), in particular any chain length between 1 and 14. These spacers can in turn be bound to various reactive groups that are naturally present on the nucleic acid oligomer or are attached to them by modification.
DNA DesoxyribonukleinsäureDNA deoxyribonucleic acid
RNA RibonukleinsäureRNA ribonucleic acid
PNA Peptidnukleinsäure (synthetische DNA oder RNA, bei der die Zucker-Phosphat-Einheit durch eine Aminosäure ersetzt ist. Bei Ersatz der Zucker-Phosphat-Einheit durch die -NH- (CH2)2-N(COCH2-Base)-CH2CO-Einheit hybridisiert PNA mit DNA).PNA Peptide nucleic acid (synthetic DNA or RNA in which the sugar-phosphate unit is replaced by an amino acid. When the sugar-phosphate unit is replaced by the -NH- (CH 2 ) 2 -N (COCH 2 base) -CH 2 CO unit hybridizes PNA with DNA).
A AdeninA adenine
G GuaninG guanine
Cytosin Thymincytosine thymine
Base A, G, T oder CBase A, G, T or C
Bp BasenpaarBp base pair
Nukleinsäure Wenigstens zwei kovalent verbundene Nukieotide oder wenigstens zwei kovalent verbundene Pyrimidin- (z.B. Cytosin, Thymin oder Uracil) oder Purin-Basen (z.B. Adenin oder Guanin). Der Begriff Nukleinsäure bezieht sich auf ein beliebiges "Rückgrat" der kovalent verbundenen Pyrimidin- oder Purin-Basen, wie z.B. auf das Zucker-Phosphat Rückgrat der DNA, cDNA oder RNA, auf ein Peptid- Rückgrat der PNA oder auf analoge Strukturen (z.B. Phosphoramid-, Thio-Phosphat- oder Dithio-Phosphat- Rückgrat). Wesentliches Merkmal einer Nukleinsäure im Sinne der vorliegenden Erfindung ist die sequenzspezifische Bindung natürlich vorkommender cDNA oder RNA.Nucleic acid At least two covalently linked nucleotides or at least two covalently linked pyrimidine (e.g. cytosine, thymine or uracil) or purine bases (e.g. adenine or guanine). The term nucleic acid refers to any "backbone" of the covalently linked pyrimidine or purine bases, such as e.g. on the sugar-phosphate backbone of the DNA, cDNA or RNA, on a peptide backbone of the PNA or on analogous structures (e.g. phosphoramide, thio-phosphate or dithio-phosphate backbone). An essential feature of a nucleic acid in the sense of the present invention is the sequence-specific binding of naturally occurring cDNA or RNA.
Nukleinsäure- Nukleinsäure nicht näher spezifizierter Basenlänge (z.B. Oligomer Nukleinsäure-Oktamer: eine Nukleinsäure mit beliebigem Rückgrat, bei dem 8 Pyrimidin- oder Purin-Basen kovalent aneinander gebunden sind).Nucleic acid - nucleic acid of unspecified base length (e.g. oligomeric nucleic acid octamer: a nucleic acid with any backbone in which 8 pyrimidine or purine bases are covalently bound to one another).
Oligomer Äquivalent zu Nukleinsäure-Oligomer.Oligomer equivalent to nucleic acid oligomer.
Oligonukleotid Äquivalent zu Oligomer oder Nukleinsäure-Oligomer, also z.B. ein DNA-, PNA- oder RNA-Fragment nicht näher spezifizierter Basenlänge.Oligonucleotide equivalent to oligomer or nucleic acid oligomer, e.g. a DNA, PNA or RNA fragment of unspecified base length.
Oligo Abkürzung für Oligonukleotid.Oligo Abbreviation for oligonucleotide.
ss Single Strand (Einzelstrang) K Assoziationskonstantess Single Strand K association constant
[S] Tatsächliche Belegungsdichte der Sondenmoleküle an der Oberfläche nach Bindung der Liganden an die Ligaten.[S] Actual density of the probe molecules on the surface after binding of the ligands to the ligates.
[ST] Belegungsdichte der Komplexe aus Target und Sondenmolekül an der Oberfläche.[ST] Surface density of the complexes of target and probe molecule.
So Gesamtbelegungsdichte der Sondenmoleküle an der Oberfläche.So total occupancy of the probe molecules on the surface.
[TJ Targetkonzentration[TJ target concentration
Die vorliegende Erfindung betrifft ein Substrat zum Einsatz als Träger von Ligaten bei einem Verfahren zur Detektion von Ligat-Ligand-Assoziationsereignissen. Auf dem Substrat sind Teststellen angeordnet, die an die Oberfläche gebundene Ligaten aufweisen. Es sind wenigstens zwei Arten von Teststellen vorgesehen, wobei die einzelnen Teststelien mit verschiedenen Arten von Ligaten belegt sind. Durch diese verschiedenen Arten von Ligaten werden jeweils komplementäre Arten von Liganden detektiert, welche in einer Analytlösung in unterschiedlichen Konzentrationsbereichen vorliegen. Die Teststellen weisen einen charakteristischen Belegungsparameter auf, so dass eine Detektion der Liganden in dem Konzentrationsbereich ermöglicht wird, in dem der jeweilige Ligand in der Analytlösung vorliegt.The present invention relates to a substrate for use as a carrier for ligates in a method for the detection of ligate-ligand association events. Test sites which have ligates bound to the surface are arranged on the substrate. At least two types of test sites are provided, the individual test sites being occupied with different types of ligates. These different types of ligates each detect complementary types of ligands which are present in an analyte solution in different concentration ranges. The test sites have a characteristic occupancy parameter, so that the ligands can be detected in the concentration range in which the respective ligand is present in the analyte solution.
Ein Sensor mit einer gegebenen Anzahl von spezifischen Kopplungsstellen erreicht ab einer gewissen Analyt-Konzentration in der Testsubstanz einen Sättigungswert, so dass eine weitere Erhöhung der Konzentration nicht mehr detektiert werden kann. Dies lässt sich theoretisch mit einer Bindungskinetik erster Ordnung für die Bindung einer Sonde S auf der Sensoroberfläche und einem Target T in der Testsubstanz zu einem Oberflächenkomplex ST mit einer Assoziationskonstante K beschreiben: A sensor with a given number of specific coupling points reaches a saturation value from a certain analyte concentration in the test substance, so that a further increase in the concentration can no longer be detected. This can theoretically be described with first-order binding kinetics for the binding of a probe S on the sensor surface and a target T in the test substance to form a surface complex ST with an association constant K:
Für die Oberflächenbelegungsdichten gilt: [S] = S0 - [ST], wobei S0 die Gesamtbelegungsdichte der Sonden und [S] die Belegungsdichte freier Sonden im thermodynamischen Gleichgewicht darstellt. Formt man obige Gleichung um, erhält man einen Ausdruck [ST] / S0 für den relativen Anteil der Oberflächenkomplexe:The following applies to the surface coverage densities: [S] = S 0 - [ST], where S 0 represents the total occupancy density of the probes and [S] the occupancy density of free probes in thermodynamic equilibrium. If one transforms the above equation, one obtains an expression [ST] / S 0 for the relative proportion of the surface complexes:
[ST] / S0 = K-[T] / (1 + K-[T]) = 1 - [S] / So (2)[ST] / S 0 = K- [T] / (1 + K- [T]) = 1 - [S] / So (2)
Dieser Ausdruck als Funktion der auf die Assoziationskonstante K normierten Oberflächenbelegungsdichte S0 ist in der Figur 1 für vier verschiedene Target- Konzentrationen [T] dargestellt und entspricht den bekannten Langmuir- Bindungsisothermen. Im Falle von Bindungsereignissen, die nicht mehr voneinander unabhängig sind und deren Bindungsenergien einer Verteilung unterliegen, ist das angmu/r-Modell jedoch nicht mehr gültig. Es entstehen heterogene Adsorptionsisothermen, die z.B. durch das S/ s-Modell beschrieben werden:This expression as a function of the surface coverage density S 0 normalized to the association constant K is shown in FIG. 1 for four different target concentrations [T] and corresponds to the known Langmuir binding isotherms. In the case of binding events that are no longer independent of one another and whose binding energies are subject to a distribution, the angmu / r model is no longer valid. Heterogeneous adsorption isotherms arise, which are described, for example, by the S / s model:
[ST] / S0 = (K.[T]) / (1 + (K.r ]) ) (3)[ST] / S 0 = (K. [T]) / (1 + (Kr])) (3)
wobei a ein Parameter (a ≤ 1) ist, der eine Pseudo-Gauß-Verteilung von Bindungsenergien darstellt. Für a = 1 geht obige Formel wieder in die Langmuir- Isotherme über.where a is a parameter (a ≤ 1) that represents a pseudo-Gaussian distribution of binding energies. For a = 1 the above formula goes back to the Langmuir isotherm.
An der Darstellung des Langπw/r-Modells (Figur 1) ist ersichtlich, dass sich für eine gegebene Analyt-Konzentration der Anteil der Bindungsereignisse ab einer Sondenzahl kleiner einer gewissen Grenze nicht mehr erhöht. In diesem Bereich spricht man von „ambient analyte conditions" (US 5,807,755). Die Anzahl der Sonden auf dem Sensor führt zu keiner merklichen Verarmung (weniger als 10 %) der Targets in der Testsubstanz. Unter „ambient analyte conditions" führt eine Erhöhung der Analyt-Konzentration nur zu einer parallelen Verschiebung des Plateaus zu höheren Anteilen von Bindungsereignissen. Nach einer Erhöhung um 2 bis 3 Größenordnungen wird die Sättigung des Sensors erreicht. Liegt also bei gegebener Assoziationskonstante und Sondenzahl des Sensors eine Analyt-Konzentration vor, die zu einer relativen Belegung (vgl. [TS]/S0 in Figur 1) nahe 1 führt, so sind weitere Konzentrationserhöhungen dieser Spezies in der Testsubstanz nicht mehr zu detektieren. Erhöht man jedoch die Sondenzahl des Sensors für einen in zu hoher Konzentration vorliegenden Target-Typ der Testsubstanz bzw. bringt man diese Sonden bei gleicher Belegungsdichte auf größere Elektroden auf, so lässt sich die relative Belegung dieser Reaktion senken und so die Sensitivität optimieren.From the representation of the Langπw / r model (FIG. 1) it can be seen that for a given analyte concentration the proportion of binding events no longer increases from a number of probes below a certain limit. In this area one speaks of "ambient analyte conditions" (US 5,807,755). The number of probes on the sensor does not lead to any noticeable depletion (less than 10%) of the targets in the test substance. Under "ambient analyte conditions" an increase in Analyte concentration only for a parallel shift of the plateau to higher proportions of binding events. After an increase of 2 to 3 orders of magnitude, the saturation of the sensor is reached. If there is an analyte concentration for a given association constant and number of probes of the sensor, which leads to a relative occupancy (cf. [TS] / S 0 in FIG. 1) close to 1, then further increases in the concentration of this species in the test substance can no longer be detected , However, if the number of probes of the sensor for a target type of the test substance present in too high a concentration is increased or if these probes are applied to larger electrodes with the same occupancy density, the relative occupation of this reaction can be reduced and thus the sensitivity can be optimized.
Durch die vorliegende Erfindung wird ein Sensor mit einem im Hinblick auf die Untersuchung von Analytflüssigkeiten, die Analyten in sehr unterschiedlichen Konzentrationen enthalten, optimierten „dynamic ränge" bereitgestellt.The present invention provides a sensor with a "dynamic ranks" optimized with regard to the analysis of analyte liquids which contain analytes in very different concentrations.
Der vorliegenden Erfindung liegt die Idee zu Grunde, dass durch Optimierung des „dynamic ränge" eines Sensors Änderungen in den Konzentrationen von Bestandteilen einer flüssigen Testsubstanz auch dann parallel detektiert werden können, wenn die Ausgangskonzentrationen dieser Bestandteile um viele Größenordnungen streuen.The present invention is based on the idea that by optimizing the "dynamic range" of a sensor, changes in the concentrations of constituents of a liquid test substance can also be detected in parallel if the initial concentrations of these constituents vary by many orders of magnitude.
Bevorzugt kommt das Substrat der Erfindung als Träger von Biomolekülen bei einem Verfahren zur elektrochemischen bzw. fluoreszenzspektroskopischen Detektion von Bestandteilen einer Elektrolytlösung zum Einsatz. Das erfindungsgemäße Substrat kann auch in einem elektrochemischen bzw. fluoreszenzspektroskopischen Verfahren zum Nachweis von Biomolekülen verwendet werden.The substrate of the invention is preferably used as a carrier of biomolecules in a method for the electrochemical or fluorescence spectroscopic detection of components of an electrolyte solution. The substrate according to the invention can also be used in an electrochemical or fluorescence spectroscopic method for the detection of biomolecules.
Die vorliegende Erfindung beschreibt einen Sensor mit räumlich begrenzten Gebieten verschiedener Sonden-Moleküle (Spots), die spezifisch je ein oder mehrere Target-Moleküle aus einer Testsubstanz binden können. Die Spots der Erfindung sind in Größe und/oder Oberflächenbelegung der Sonden (charakteristische Belegungsparameter des Substrats) so auf die zu detektierenden Konzentrationsbereiche der entsprechenden Targets optimiert, dass der Anteil an Bindungsereignissen aller Spots für z.B. den nicht-pathogenen Zustand unabhängig von der eigentlichen Konzentration ihrer Targets in etwa gleich ist. Dadurch lässt sich der spezifische „dynamic ränge" eines Sensors auf diesen „Anfangszustand" normieren. Der Vorteil dieses Verfahrens liegt in der angeglichenen Sensitivität aller Spots hinsichtlich der zu detektierenden Konzentrationsänderungen der entsprechenden Targets unabhängig von deren Anfangskonzentration. Der Sensor ist somit auf den „tolerierbaren" Konzentrationsbereich zwischen dem „erlaubten", nicht-pathogenen Wert und dem „kritischen", pathogenen Wert jedes Analyten optimiert.The present invention describes a sensor with spatially limited areas of different probe molecules (spots), each of which can specifically bind one or more target molecules from a test substance. The size and / or surface coverage of the probes (characteristic coverage parameters of the substrate) of the spots of the invention are optimized for the concentration ranges of the corresponding targets to be detected in such a way that the proportion of binding events of all spots for, for example, the non-pathogenic state is independent of the actual concentration of the spots Targets is roughly the same. This leaves the specific "dynamic ranks" of a sensor normalize to this "initial state". The advantage of this method lies in the adjusted sensitivity of all spots with regard to the changes in concentration of the corresponding targets to be detected, regardless of their initial concentration. The sensor is thus optimized for the “tolerable” concentration range between the “permitted”, non-pathogenic value and the “critical”, pathogenic value of each analyte.
Für die Optimierung des Sensors sollten also die „erlaubten", nicht-pathogenen Konzentrationen der Analyten der Testflüssigkeiten zu Beginn einer Experimentserie bekannt sein. Speziell im Bereich der Genexpressionsanalyse oder der Identifikation von Keimen ist die Zusammensetzung des Analyt-Pools eines gesunden Organismus in der Regel hinreichend bekannt, so dass mit dem vorliegenden Verfahren anhand der Änderungen von einzelnen Analyten Indizien für eine Erkrankung (Überschreitung des „kritischen" Konzentrationswertes eines Analyten) geliefert werden können.In order to optimize the sensor, the "allowed", non-pathogenic concentrations of the analytes of the test liquids should be known at the beginning of a series of experiments. Especially in the area of gene expression analysis or the identification of germs, the composition of the analyte pool of a healthy organism is generally the rule sufficiently known that the present method can be used to provide evidence of a disease (exceeding the "critical" concentration value of an analyte) on the basis of changes in individual analytes.
Für das quantitative Auslesen der verschiedenen Spots des Sensors in Bezug auf mögliche Bindungsereignisse kommen im Rahmen der vorliegenden Erfindung alle geeigneten Messmethoden in Abhängigkeit von den verwendeten Substraten und den jeweiligen Biomolekülen in Frage.For the quantitative readout of the different spots of the sensor with regard to possible binding events, all suitable measurement methods are possible within the scope of the present invention, depending on the substrates used and the respective biomolecules.
Unter Verwendung der erfindungsgemäßen Substrate werden bevorzugt verschiedene Arten von Liganden detektiert, die in der Analyt-Lösung in Konzentrationsbereichen vorliegen, deren Mittelwerte sich um wenigstens einen Faktor 10 unterscheiden. Unter dem Mittelwert cm eines Konzentrationsbereichs wird der Wert cm = ((cmax - cmjn) / 2) + cmin verstanden, wobei cmaχ die maximale Konzentration und cmin die minimale Konzentration bedeutet. Bevorzugt können verschiedene Arten von Liganden detektiert werden, wobei sich die Mittelwerte der Konzentrationsbereiche, in denen sie in der Analyt-Lösung vorliegen, um wenigstens einen Faktor 100, insbesondere bevorzugt um wenigstens einen Faktor 1000, ganz besonders bevorzugt um wenigstens einen Faktor 10000 unterscheiden. Die vorliegende Erfindung umfasst auch die Verwendung der Substrate in Verfahren zur Detektion von Ligat-Ligand-Assoziationsereignissen.Using the substrates according to the invention, different types of ligands are preferably detected which are present in the analyte solution in concentration ranges whose mean values differ by at least a factor of 10. The mean value c m of a concentration range means the value c m = ((c max - c m j n ) / 2) + c min , where c m aχ means the maximum concentration and c min the minimum concentration. Different types of ligands can preferably be detected, the mean values of the concentration ranges in which they are present in the analyte solution differ by at least a factor of 100, particularly preferably by at least a factor of 1000, very particularly preferably by at least a factor of 10,000. The present invention also includes the use of the substrates in methods for the detection of ligate-ligand association events.
Die Substrate können insbesondere in fluoreszenzspektroskopischen und elektrochemischen Nachweisverfahren verwendet werden. Als elektrochemische Nachweisverfahren kommen Chronoamperometrie (CA), Chronocoulometrie (CC), Linear Sweep Voltammetrie (LSV), zyklische Voltammetrie (CSV), Altemating current voltammetry (ACV), Voltammetrietechniken mit verschiedenen Pulsformen, insbesondere Square Wave Voltammetrie (SWV), Differential Pulse Voltammetrie (DPV) oder Normal Pulse Voltammetrie (NPV), AC Impedanzspektroskopie, Chronopotentiometrie und zyklische Chronopotentiometrie in Frage.The substrates can be used in particular in fluorescence spectroscopic and electrochemical detection methods. Chronoamperometry (CA), chronocoulometry (CC), linear sweep voltammetry (LSV), cyclic voltammetry (CSV), altemating current voltammetry (ACV), voltammetry techniques with different pulse shapes, in particular square wave voltammetry (SWV), differential pulse voltammetry are used as electrochemical detection methods (DPV) or Normal Pulse Voltammetry (NPV), AC Impedance Spectroscopy, Chronopotentiometry and Cyclic Chronopotentiometry in question.
Sensor-Substrate mit aktiven Flächen verschiedener GrößenSensor substrates with active areas of various sizes
Gemäß einer besonders bevorzugten Ausführungsform der vorliegenden Erfindung handelt es sich bei dem charakteristischen Belegungsparameter des Substrats um die Größe der Fläche der einzelnen Teststellen. Bevorzugt unterscheidet sich die Fläche der Teststellen um mindestens den Faktor 10, besonders bevorzugt um mindestens den Faktor 100, insbesondere bevorzugt um mindestens den Faktor 1000 und ganz besonders bevorzugt um mindestens den Faktor 10000.According to a particularly preferred embodiment of the present invention, the characteristic occupancy parameter of the substrate is the size of the area of the individual test sites. The area of the test sites preferably differs by at least a factor of 10, particularly preferably by at least a factor of 100, particularly preferably by at least a factor of 1000 and very particularly preferably by at least a factor of 10000.
Bevorzugt werden Substrate, die Teststellen-Flächen zwischen 1 μm2 und 1 mm2 aufweisen. Besonders bevorzugt werden Substrate, die Teststellen-Flächen zwischen 10 μm2 und 100000 μm2 aufweisen.Preference is given to substrates which have test site areas between 1 μm 2 and 1 mm 2 . Substrates which have test site areas between 10 μm 2 and 100000 μm 2 are particularly preferred.
Als Sensor-Substrate eignen sich im Rahmen der vorliegenden Erfindung alle Festkörper mit frei zugänglicher Oberfläche, die mit Biomolekülen funktionalisiert und mit einer flüssigen Testsubstanz benetzt werden können. Als Festkörpersubstrate kommen sowohl Kunststoffe als auch Metalle, Halbleiter, Gläser, Verbundstoffe oder poröse Materialien in Frage. Die Bezeichnung Oberfläche ist unabhängig von den räumlichen Dimensionen der Oberfläche. Die Oberfläche des Sensors muss in räumlich getrennte Bereiche unterteilbar sein. Dies lässt sich durch Strukturierung des Festkörpersubstrats in aktive und inaktive Bereiche oder durch partielle Funktionalisierung seiner homogenen Oberfläche realisieren.In the context of the present invention, all solid bodies with a freely accessible surface that can be functionalized with biomolecules and wetted with a liquid test substance are suitable as sensor substrates. Solid substrates include plastics as well as metals, semiconductors, glasses, composites or porous materials. The term surface is independent of the spatial dimensions of the surface. The surface of the sensor must be divisible into separate areas. This can be achieved by structuring the solid-state substrate into active and inactive areas or by partially functionalizing its homogeneous surface.
Die Strukturierung der Festkörpersubstrate in aktive und inaktive Bereiche lässt sich z.B. durch Lithographie, Vakuumabscheidung, elektrochemische Abscheidung, Dotieren oder Laserbehandlung erreichen. Auf homogenen Substraten kann man die Strukturierung durch Aufbringen und Strukturierung von Passivierungsschichten realisieren. Erfindungsgemäß eignet sich als Passivierungsschicht jedes beliebige Material, das an einer Oberfläche eine geschlossene Schicht bildet und somit die Substratoberfläche von der Umgebung trennt. Zu einem späteren Zeitpunkt kann das Material z.B. durch Laser-Ablation an den gewünschten Stellen in seiner gesamten Dicke rückstandsfrei entfernt werden.The structuring of the solid state substrates into active and inactive areas can be e.g. by lithography, vacuum deposition, electrochemical deposition, doping or laser treatment. The structuring on homogeneous substrates can be achieved by applying and structuring passivation layers. According to the invention, any material that forms a closed layer on a surface and thus separates the substrate surface from the environment is suitable as a passivation layer. At a later time the material can e.g. can be removed in its entire thickness without residue by laser ablation at the desired locations.
Auch ohne Strukturierung der Substrate können räumlich getrennte Bereiche unterschiedlicher Funktionalisierung hergestellt werden. Hier sei exemplarisch auf das Mikrokontakt-Drucken μCP (mico-contact-printing), das erstmals von Whitesides 1994 (A. Kumar, G.M. Whitesides, Science, 1994, 263, 60) vorgestellt wurde, hingewiesen. Bei diesem Verfahren wird ein mikrostrukturierter Stempel mit einer Flüssigkeit benetzt, anschließend in direktem Kontakt mit dem zu bearbeitenden Substrat gebracht und so der Oberfläche eine laterale chemische Struktur aufgeprägt.Spatially separated areas of different functionalization can also be produced without structuring the substrates. The micro-contact printing μCP (mico-contact printing), which was first introduced by Whitesides 1994 (A. Kumar, G.M. Whitesides, Science, 1994, 263, 60), is mentioned here as an example. In this method, a microstructured stamp is wetted with a liquid, then brought into direct contact with the substrate to be processed, and a lateral chemical structure is thus imprinted on the surface.
In einer bevorzugten Ausführungsform der vorliegenden Erfindung werden elektrisch leitfähige Materialien wie Platin, Palladium, Gold, Cadmium, Quecksilber, Nickel, Zink, Kohlenstoff, Silber, Kupfer, Eisen, Blei, Aluminium, Mangan, beliebige dotierte oder nicht-dotierte Halbleiter und binäre oder ternäre Verbindungen als Oberflächen der Sensorsubstrate verwendet. Zur Realisierung von räumlich getrennten aktiven Test-Sites bzw. Spots auf dem Sensor können homogene elektrisch leitfähige Oberflächen strukturiert werden oder aber leitfähige Materialien auf räumlich getrennte Bereiche eines nicht-leitfähigen Substrats, wie z.B. Glas oder Kunststoff in beliebiger Dicke aufgebracht werden. Gemäß einer besonders bevorzugten Ausführungsform der vorliegenden Erfindung werden als Sensorsubstrate isolierende Trägerplatten verwendet, die zweckmäßig einseitig starre Trägerplatten, doppelseitig starre Trägerplatten oder starre Mehrlagenträgerplatten sind. Alternativ kann die isolierende Trägerplatte eine einseitige oder doppelseitige flexible Trägerplatte, insbesondere aus einer Polyimidfolie oder eine starr-flexible Trägerplatte sein. Sie besteht mit Vorteil aus einem Basismaterial, das ausgewählt ist aus der Gruppe BT (Bismaleinimid- Triazinharz mit Quarzglas), CE (Cyanatester mit Quarzglas), CEM1 (Hartpapierkern mit FR4-Außenlagen), CEM3 (Glasvlieskern mit FR4-Außenlagen), FR2 (Phenolharzpapier), FR3 (Hartpapier), FR4 (Epoxid-Glashartgewebe), FR5 (Epoxid- Glashartgewebe mit vernetztem Harzsystem), PD (Polyimidharz mit Aramidverstärkung), PTFE (Polytetrafiuorethylen mit Glas oder Keramik), CHn (hochvernetzte Kohlenwasserstoffe mit Keramik) und Glas.In a preferred embodiment of the present invention, electrically conductive materials such as platinum, palladium, gold, cadmium, mercury, nickel, zinc, carbon, silver, copper, iron, lead, aluminum, manganese, any doped or undoped semiconductors and binary or ternary connections are used as surfaces of the sensor substrates. To implement spatially separated active test sites or spots on the sensor, homogeneous electrically conductive surfaces can be structured or conductive materials can be applied to spatially separated areas of a non-conductive substrate, such as glass or plastic, in any thickness. According to a particularly preferred embodiment of the present invention, insulating carrier plates are used as sensor substrates, which are expediently rigid carrier plates on one side, rigid carrier plates on both sides or rigid multilayer carrier plates. Alternatively, the insulating carrier plate can be a one-sided or double-sided flexible carrier plate, in particular made of a polyimide film, or a rigid-flexible carrier plate. It advantageously consists of a base material that is selected from the group BT (bismaleimide triazine resin with quartz glass), CE (cyanate ester with quartz glass), CEM1 (hard paper core with FR4 outer layers), CEM3 (glass fleece core with FR4 outer layers), FR2 ( Phenolic resin paper), FR3 (hard paper), FR4 (epoxy glass hard fabric), FR5 (epoxy glass hard fabric with cross-linked resin system), PD (polyimide resin with aramid reinforcement), PTFE (polytetrafluoroethylene with glass or ceramic), CHn (highly cross-linked hydrocarbons with ceramic) and glass ,
Diese Trägerplatten weisen eine gewisse Anzahl von Leiterbahnen mit einer Goldoberfläche auf, die mit einer Lötstopplackschicht als Passivierung überzogen sind. An einem Ende der Leiterbahnen befinden sich Kontakte für elektrochemische Untersuchungen, am anderen Ende werden mit einer Laser-Ablation freie Goldstellen für die spätere Funktionalisierung in den Lack gebrannt. Mit Hilfe der Laser-Ablation lassen sich Spots beliebiger Größe und Geometrie in den Lack schreiben, wobei nur die Breite der Leiterbahnen eine Grenze darstellt. Die Laser- Ablation entfernt erfindungsgemäß nicht nur die Lackschicht an gewünschten Stellen, sondern sorgt durch das kurzzeitige Aufschmelzen der Goldoberfläche auch für die Reduktion der Oberflächenrauigkeit und das Verschließen von Poren. Durch das Aufschmelzen der Substrate werden zusätzlich wenige Goldlagen von der Oberfläche ablatiert und somit Verunreinigungen entfernt.These carrier plates have a certain number of conductor tracks with a gold surface, which are coated with a solder resist layer as a passivation. At one end of the conductor tracks there are contacts for electrochemical investigations, at the other end laser gold ablation is used to burn free gold spots into the lacquer for later functionalization. With the help of laser ablation, spots of any size and geometry can be written in the lacquer, whereby only the width of the conductor tracks represents a limit. According to the invention, laser ablation not only removes the lacquer layer at desired points, but also ensures that the surface of the gold is temporarily melted and the pores are reduced by melting it briefly. By melting the substrates, a few gold layers are additionally ablated from the surface, thus removing impurities.
Die gerade beschriebenen Leiterbahn-Substrate eignen sich sowohl für elektrochemische Messmethoden als auch für die Fluoreszenz-Spektroskopie. Funktionalisierung der aktiven Flächen mit LigatenThe conductor track substrates just described are suitable both for electrochemical measurement methods and for fluorescence spectroscopy. Functionalization of the active areas with ligates
Die aktiven Bereiche des Sensors sind mit Ligaten funktionalisiert, die als Sonden für die in der Testsubstanz vorhandenen Liganden fungieren. Im Rahmen der vorliegenden Erfindung eignen sich alle Arten von Ligaten, um Analytflüssigkeiten auf das Vorhandensein ihrer spezifischen Liganden zu untersuchen. Als Ligaten werden Moleküle bezeichnet, die spezifisch mit einem Liganden unter Ausbildung eines Komplexes wechselwirken. Beispiele von Ligaten im Sinne der vorliegenden Schrift sind Substrate, Cofaktoren oder Coenzyme als Komplexbindungspartner eines Proteins (Enzyms), Antikörper (als Komplexbindungspartner eines Antigens), Antigene (als Komplexbindungspartner eines Antikörpers), Rezeptoren (als Komplexbindungspartner eines Hormons), Hormone (als Komplexbindungspartner eines Rezeptors), Nukleinsäure-Oligomere (als Komplexbindungspartner des komplementären Nukleinsäure-Oligomers) oder Metallkomplexe.The active areas of the sensor are functionalized with ligates, which act as probes for the ligands present in the test substance. In the context of the present invention, all types of ligates are suitable for examining analyte liquids for the presence of their specific ligands. Molecules that specifically interact with a ligand to form a complex are referred to as ligates. Examples of ligates in the sense of the present document are substrates, cofactors or coenzymes as complex binding partners of a protein (enzyme), antibodies (as complex binding partners of an antigen), antigens (as complex binding partners of an antibody), receptors (as complex binding partners of a hormone), hormones (as complex binding partners of a receptor), nucleic acid oligomers (as complex binding partner of the complementary nucleic acid oligomer) or metal complexes.
Für die Kopplung der Biomoleküle mit der Sensoroberfläche stehen aus dem Stand der Technik eine Vielzahl von Möglichkeiten zur Verfügung. Beispiele hierfür sind: (i) Thiol- (HS-) oder Disulfid- (S-S-) Gruppen, die an Oberfläche aus Au, Ag, Cd, Hg und Cu koppeln, (ii) Amine, die sich durch Chemi- oder Physisorption an Platin-, Silizium- oder Kohlenstoff-Oberflächen anlagern, (iii) Silane, die mit oxidischen Oberflächen eine kovalente Bindung eingehen und (iv) Epoxy-Zement, der an alle leitfähigen Oberflächen bindet (Heller et al., Sensors and Actuators, 1993, 180, 13- 14; Pishko et al., Anal. Chem., 1991, 63, 2268; Gregg and Heller, J. Phys. Chem., 1991 , 95, 5970-5975).A large number of possibilities are available from the prior art for coupling the biomolecules to the sensor surface. Examples of these are: (i) thiol (HS) or disulfide (SS) groups, which couple to the surface of Au, Ag, Cd, Hg and Cu, (ii) amines, which undergo chemical or physical sorption Add platinum, silicon or carbon surfaces, (iii) silanes that form a covalent bond with oxidic surfaces and (iv) epoxy cement that binds to all conductive surfaces (Heller et al., Sensors and Actuators, 1993, 180, 13-14; Pishko et al., Anal. Chem., 1991, 63, 2268; Gregg and Heller, J. Phys. Chem., 1991, 95, 5970-5975).
Zur Immobilisierung der Sonden werden Methoden bevorzugt, bei der die Anzahl der Sonden auf der Sensoroberfläche linear mit der Fläche skaliert, also z.B. das Aufbringen von Sonden-Monolagen unter Bedingungen, die eine Belegung kleiner der dichtesten Packung ermöglichen. Im Rahmen der vorliegenden Erfindung sind aber auch „Volumenverfahren" zur Immobilisierung der Sonden z.B. über funktionalisierte Polymere denkbar, solange die Sondenanzahl weiter mit der Fläche skaliert. Bevorzugt werden die freien Substratstellen mit modifizierten Nukleinsäure- Oligomeren in wässriger Lösung benetzt. Das Nukleinsäure-Oligomer, das auf die freie Oberfläche aufgebracht werden soll, ist über einen kovalent angebundenen Spacer beliebiger Zusammensetzung und Kettenlänge mit einer oder mehreren reaktiven Gruppen modifiziert, wobei sich diese reaktiven Gruppen bevorzugt in der Nähe eines Endes des Nukleinsäure-Oligomers befinden. Bei den reaktiven Gruppen handelt es sich bevorzugt um Gruppen, die direkt mit der unmodifizierten Oberfläche reagieren können. Beispiele hierfür sind: (i) Thiol- (HS-) oder Disulfid- (S-S-) derivatisierte Nukleinsäure-Oligomere der allgemeinen Formel (n x HS- Spacer)-oligo, (n x R-S-S-Spacer)-oligo oder oligo-Spacer-S-S-Spacer-oligo, die mit einer Goldoberfläche unter Ausbildung von Gold-Schwefelbindungen reagieren, (ii) Nukleinsäure-Oligomere mit Aminen, die sich durch Chemi- oder Physisorption an Platin- oder Silizium-Oberflächen anlagern und (iii) Nukleinsäure-Oligomere mit Silanen, die mit oxidischen Oberflächen eine kovalente Bindung eingehen. Bei diesen Arten der Anbindung von Nukleinsäure-OIigomeren werden in der Regel Belegungen kleiner der dichtesten Packung realisiert, so dass für eine spätere Hybridisierung ausreichend Platz auf der Oberfläche zur Verfügung steht.For immobilizing the probes, methods are preferred in which the number of probes on the sensor surface scales linearly with the surface, for example the application of probe monolayers under conditions which enable an occupancy of less than the densest packing. In the context of the present invention, however, “volume methods” for immobilizing the probes, for example via functionalized polymers, are also conceivable as long as the number of probes continues to scale with the area. The free substrate sites are preferably wetted with modified nucleic acid oligomers in aqueous solution. The nucleic acid oligomer which is to be applied to the free surface is modified via a covalently attached spacer of any composition and chain length with one or more reactive groups, these reactive groups preferably being located near one end of the nucleic acid oligomer. The reactive groups are preferably groups that can react directly with the unmodified surface. Examples of these are: (i) thiol (HS) or disulfide (SS) derivatized nucleic acid oligomers of the general formula (nx HS spacer) oligo, (nx RSS spacer) oligo or oligo spacer SS -Spacer-oligo, which react with a gold surface to form gold-sulfur bonds, (ii) nucleic acid oligomers with amines that attach to platinum or silicon surfaces by chemical or physical sorption and (iii) nucleic acid oligomers with silanes that form a covalent bond with oxidic surfaces. With these types of attachment of nucleic acid oligomers, deposits of less than the densest packing are generally realized, so that there is sufficient space on the surface for later hybridization.
Am anderen Ende des Nukleinsäure-Oligomers kann das Molekül bei Bedarf über einen weiteren Spacer beliebiger Zusammensetzung und Kettenlänge zusätzlich mit einem elektrochemischen Label modifiziert werden, wenn die Funktionalisierung der freien Substratstellen und die spätere Hybridisierung mit Hilfe elektrochemischerAt the other end of the nucleic acid oligomer, the molecule can also be modified with an electrochemical label if necessary via a further spacer of any composition and chain length, if the functionalization of the free substrate sites and the subsequent hybridization using electrochemical
Methoden untersucht werden sollen. Auch ohne die Modifikation der Sonden-Methods should be examined. Even without modification of the probe
Oligonukleotide mit einem Redox-Label können elektrochemische Methoden zur Untersuchung der Hybridisierungsereignisse verwendet werden, wenn alternativ dieOligonucleotides with a redox label can be used electrochemical methods to investigate the hybridization events, if the
Targetmoleküle mit einem Redox-Label versehen sind. Eine weitere elektrochemische Detektionsvariante stellt ein Verdrängungsassay dar, bei dem an die ungelabelten Sonden-Oligomere gebundene, kurzkettige Signal-Oligomere mitTarget molecules are provided with a redox label. Another electrochemical detection variant is a displacement assay, in which short-chain signal oligomers are also bound to the unlabeled probe oligomers
Redox-Label von ungelabelten Target-Oligomeren der Komplementärsequenz verdrängt werden.Redox labels of unlabeled target oligomers of the complementary sequence are displaced.
Als Redox-Label der Ligaten oder Liganden können Übergangsmetallkomplexe, insbesondere solche des Kupfers, Eisens, Rutheniums, Osmiums oder Titans mit Liganden wie Pyridin, 4,7-Dimethylphenanthrolin, 9,10-Phenanthrenchinondiimin, Porphyrine und substituierte Porphyrin-Derivate verwendet werden. Daneben ist der Einsatz von Riboflavin, von Chinonen wie Pyrrollochinolinochinon, Ubichinon, Anthrachinon, Naphtochinon oder Menachinon bzw. Derivaten davon, von Metallocenen und Metallocenderivaten wie Ferrocenen und Ferrocenderivaten, Cobaltocenen und Cobaltocenderivaten, von Porphyrinen, Methylenblau, Daunomycin, Dopamin-Derivaten, Hydrochinon-Derivaten (para- oder ortho- dihydroxy-Benzol-Derivaten, para- oder ortho-dihydroxy-Anthrachinon-Derivaten, para- oder ortho-dihydroxy-Naphtochinon-Derivaten) und ähnlichen Verbindungen möglich.Transition metal complexes, in particular those of copper, iron, ruthenium, osmium or titanium with ligands such as pyridine, 4,7-dimethylphenanthroline, 9,10-phenanthrenequinone diimine, can be used as redox labels of the ligates or ligands, Porphyrins and substituted porphyrin derivatives can be used. In addition, the use of riboflavin, of quinones such as pyrrolloquinoline quinone, ubiquinone, anthraquinone, naphthoquinone or menaquinone or derivatives thereof, of metallocenes and metallocene derivatives such as ferrocenes and ferrocene derivatives, cobaltocenes and cobaltocene derivatives, of porphyrins, methylene blue, hydroquinone derivatives, daaminomycin derivatives Derivatives (para or ortho dihydroxy benzene derivatives, para or ortho dihydroxy anthraquinone derivatives, para or ortho dihydroxy naphthoquinone derivatives) and similar compounds are possible.
Alternativ zum Redox-Label können Ligaten oder Liganden als zweite Funktionalisierung über einen weiteren Spacer beliebiger Zusammensetzung und Kettenlänge ein Fluorophor erhalten, wenn die Funktionalisierung der freien Substratstellen und die spätere Hybridisierung mit Hilfe von optischen Methoden untersucht werden sollen. Analog zur elektrochemischen Analyse kann die Fluoreszenz-Spektroskopie auch mit einem Fluorophor an den Target-Molekülen und ungelabelten Sonden durchgeführt werden.As an alternative to the redox label, ligates or ligands can be given a fluorophore as a second functionalization via a further spacer of any composition and chain length if the functionalization of the free substrate sites and the subsequent hybridization are to be examined with the aid of optical methods. Analogous to electrochemical analysis, fluorescence spectroscopy can also be performed with a fluorophore on the target molecules and unlabeled probes.
Als Fluorophore können hierfür kommerziell erhältliche Fluoreszenzfarbstoffe wie z.B. Texas Red®, Rhodamin-Farbstoffe, Cy3™, Cy5™, Fluorescein etc. (vgl. Fluka, Amersham und Molecular Probes Katalog) verwendet werden.Commercially available fluorescent dyes such as e.g. Texas Red®, rhodamine dyes, Cy3 ™, Cy5 ™, fluorescein etc. (cf. Fluka, Amersham and Molecular Probes catalog) can be used.
Für die Funktionalisierung der freigelegten Substratstellen eignen sich vor allem zwei Techniken. Beim Spotting-Verfahren werden mit einem kommerziell erhältlichen Spotter kleine Volumina gezielt auf die Spots des Substrats aufgebracht, wobei jeder Spot mit verschiedenen Molekülen funktionalisiert werden kann. Alternativ können alle freigelegten Spots mit den gleichen Sonden-Molekülen funktionalisiert werden, indem das Substrat z.B. in die Sonden-Flüssigkeit getaucht wird oder aber das gesamte Substrat benetzt wird. Variation der Oberflächenkonzentration der LigatenTwo techniques are particularly suitable for the functionalization of the exposed substrate sites. In the spotting process, small volumes are selectively applied to the spots of the substrate using a commercially available spotter, each spot being able to be functionalized with different molecules. Alternatively, all exposed spots can be functionalized with the same probe molecules, for example by immersing the substrate in the probe liquid or by wetting the entire substrate. Varying the surface concentration of the ligates
Gemäß einer weiteren Ausführungsform der Erfindung kann die Anzahl der Sonden auf der Sensoroberfläche auch ohne die Variation der aktiven Spotgröße eingestellt werden. Somit können verschiedene Mengen an Sonden-Molekülen auch mit nur einem Sensor-Design auf Spots gleicher Größe realisiert werden.According to a further embodiment of the invention, the number of probes on the sensor surface can also be set without varying the active spot size. This means that different amounts of probe molecules can be realized on spots of the same size with just one sensor design.
Eine besonders bevorzugte Ausführungsform der vorliegenden Erfindung stellen also Substrate dar, deren charakteristischer Belegungsparameter die Belegungsdichte der Teststellen mit Ligaten ist.A particularly preferred embodiment of the present invention is therefore substrates whose characteristic occupancy parameter is the occupancy density of the test sites with ligates.
Besonders bevorzugt unterscheiden sich die Belegungsdichten der Teststellen mit Ligaten um mindestens den Faktor 10, insbesondere bevorzugt um mindestens den Faktor 100 und ganz besonders bevorzugt um mindestens den Faktor 1000.The occupancy densities of the test sites with ligates particularly preferably differ by at least a factor of 10, particularly preferably by at least a factor of 100 and very particularly preferably by at least a factor of 1000.
Für die Kontrolle der Oberflächenbelegung eignen sich verschiedene Varianten. Die Belegung kann z.B. über die Inkubationszeit, die Anzahl an Kopplungsgruppen pro Molekül, die Molarität des Belegungspuffers oder über die Konzentration der Moleküle in der Inkubationslösung eingestellt werden.Various variants are suitable for checking the surface assignment. The assignment can e.g. the incubation time, the number of coupling groups per molecule, the molarity of the loading buffer or the concentration of the molecules in the incubation solution.
Gemäß einer bevorzugten Ausführungsform der vorliegenden Erfindung wird die Oberflächenbelegung über ein Koadsorbat eingestellt. Hierzu wird entweder ein geeignetes Koadsorbat in einer bestimmten Konzentration zur Inkubationslösung der Sonden-Moleküle zugegeben und mit der Sensoroberfläche in Kontakt gebracht oder aber das Koadsorbat wird in einem zweiten Belegungsschritt nach der Funktionalisierung mit den Sonden aufgebracht. Das Koadsorbat weist bevorzugt dieselbe Kopplungsgruppe auf wie das Sonden-Molekül, belegt somit einen Teil der aktiven Oberfläche und sorgt für eine reduzierte Oberflächenbelegung der Sonde. Die Oberflächenbelegung lässt sich über die Konzentration des Koadsorbats in der jeweiligen Inkubationslösung einstellen.According to a preferred embodiment of the present invention, the surface coverage is set using a coadsorbate. For this purpose, either a suitable coadsorbate is added to the incubation solution of the probe molecules in a certain concentration and brought into contact with the sensor surface, or the coadsorbate is applied in a second coating step after the functionalization with the probes. The coadsorbate preferably has the same coupling group as the probe molecule, thus occupies part of the active surface and ensures a reduced surface coverage of the probe. The surface coverage can be adjusted via the concentration of the coadsorbate in the respective incubation solution.
Für die weiter oben beschriebenen Nukleinsäure-Oligomere mit Thiol- Kopplungsgruppe eignen sich besonders bevorzugt kurzkettige Thiole der aligemeinen Struktur SH-(CH2)n-X, wobei X eine beliebige Kopfgruppe sein kann. Kurze Beschreibung der ZeichnungenFor the nucleic acid oligomers described above with a thiol coupling group, short-chain thiols of the general structure SH- (CH 2 ) n -X are particularly preferred, where X can be any head group. Brief description of the drawings
Die Erfindung soll nachfolgend anhand der Ausführungsbeispiele im Zusammenhang mit den Zeichnungen näher erläutert werden. Es zeigenThe invention will be explained in more detail below on the basis of the exemplary embodiments in conjunction with the drawings. Show it
Fig. 1 Theoretische Kurven des relativen Anteils an Bindungsereignissen ([TS]/S0) für verschiedene Target-Konzentrationen. Die Konzentration der Sonden an der Sensoroberfläche ist auf die Assoziationskonstante der Bindung normiert.Fig. 1 Theoretical curves of the relative proportion of binding events ([TS] / S 0 ) for different target concentrations. The concentration of the probes on the sensor surface is normalized to the association constant of the binding.
Fig. 2 Schematisches Bild eines Ausschnitts der auf Leiterplatten-Technologie basierenden Sensor-Substrate, a) Aufsicht auf das Leiterbahnen-Substrat mit freien Substratstellen verschiedener aktiver Fläche und Geometrie, b) Querschnitt durch ein Substrat mit 3 gleichen Elektrodenspots.Fig. 2 Schematic image of a section of the sensor substrates based on circuit board technology, a) top view of the conductor track substrate with free substrate locations of different active area and geometry, b) cross section through a substrate with 3 identical electrode spots.
Fig. 3 a) Schematisches Bild eines Hybridisierungs-Experiments mit 2 Redox- Labeln. b) ACV-Kurven (Uao = 10 mV, f = 5 Hz) eines typischen Experiments auf einer Arbeitselektrode mit d = 10 μm vor und nach der Hybridisierung. Der linke Peak bei etwa U = 220 mV zeigt das Osmium der Sonde, der rechte Peak bei etwa U = 360 mV zeigt das Ferrocen des Targets. Die Potentiale sind gegen eine Ag/AgCI Referenz-Elektrode angegeben.Fig. 3 a) Schematic image of a hybridization experiment with 2 redox labels. b) ACV curves (U ao = 10 mV, f = 5 Hz) of a typical experiment on a working electrode with d = 10 μm before and after hybridization. The left peak at around U = 220 mV shows the osmium of the probe, the right peak at around U = 360 mV shows the ferrocene of the target. The potentials are given against an Ag / AgCI reference electrode.
Wege zur Ausführung der ErfindungWays of Carrying Out the Invention
Eine exemplarische Prozessführung zur Analyse einer Testflüssigkeit mit Nukleinsäure-Oligomeren mit Hilfe eines auf der Leiterplatten-Technologie basierenden Sensors ist in den folgenden Beispielen geschildert.An exemplary process control for analyzing a test liquid with nucleic acid oligomers with the aid of a sensor based on circuit board technology is described in the following examples.
Die durch Laser-Ablation freigelegten Goldstellen des Substrats werden mit doppelt modifizierten Nukleinsäure-Oligomeren funktionalisiert, die an dem einen Ende eine Thioi-Gruppe zur Bindung an die Goldoberfläche und an dem anderen Ende ein elektrochemisches Label (z.B. Osmium-Komplexe) besitzen. Die gewünschte Anzahl an Sonden auf der Sensoroberfläche wird entweder über die Elektrodengröße oder durch Verwendung eines kurzkettigen Thiols bestimmter Konzentration als Koadsorbat eingestellt. Die Nukleinsäure-Oligomere der Testflüssigkeit besitzen ebenfalls ein elektrochemisches Label (z.B. Ferrocenderivate), so dass sowohl die Belegung mit den Nukleinsäure-Oligomeren als auch die Hybridisierungs-Effizienz mit elektrochemischen Methoden bestimmt werden können.The gold sites of the substrate exposed by laser ablation are functionalized with double-modified nucleic acid oligomers, which have a thioi group at one end for binding to the gold surface and at the other end have an electrochemical label (e.g. osmium complexes). The desired number of probes on the sensor surface is set either via the electrode size or by using a short-chain thiol of a certain concentration as a coadsorbate. The nucleic acid oligomers of the test liquid also have an electrochemical label (eg ferrocene derivatives), so that both the assignment with the nucleic acid oligomers and the hybridization efficiency can be determined using electrochemical methods.
Eine bevorzugte Messmethode zur Analyse der Belegung und der Hybridisierungs- Effizienz ist die AC (alternating current) Voltammetrie. Aus dem ACV-Strom am Redox-Potential des Labels lässt sich nach O'Connor et al. (J. Electroanal. Chem., 466, 1999, 197-202) die Anzahl der beteiligten Label berechnen. Die Experimente sind somit quantitativ auswertbar.A preferred measurement method for analyzing occupancy and hybridization efficiency is AC (alternating current) voltammetry. From the ACV current at the redox potential of the label, according to O'Connor et al. (J. Electroanal. Chem., 466, 1999, 197-202) calculate the number of labels involved. The experiments can thus be evaluated quantitatively.
Die in den folgenden Beispielen geschilderten Verfahren sind für den Fachmann ohne weiteres auf die Beschichtung anderer Sensoroberflächen mit anderen Biomolekülen und auf andere Detektionsmethoden übertragbar.The methods described in the following examples are readily transferable to a person skilled in the art for coating other sensor surfaces with other biomolecules and for other detection methods.
Beispiel 1: Leiterplatten-Substrate.Example 1: PCB substrates.
Auf einer Trägerplatte aus Epoxid-Glashartgewebe FR4 wird ein Leiterbild aus fünfzig parallelen Leiterbahnen aufgebracht. Figur 2a zeigt einen Ausschnitt dieses Leiterbahnenbildes. Der Ausschnitt zeigt 4 der 48 Arbeitselektroden (20A bis 20D) und einen Teil der Gegenelektrode 28.A conductor pattern made of fifty parallel conductor tracks is applied to a carrier plate made of FR4 epoxy glass fiber fabric. FIG. 2a shows a section of this conductor track picture. The detail shows 4 of the 48 working electrodes (20A to 20D) and part of the counter electrode 28.
Das gesamte Leiterbild ist mit einer 15 μm bis 20 μm dicken Passivierungsschicht 22 (Fig. 2b) aus strukturierbaren, optisch aushärtbaren Lack (2-Komponenten Lötstopplack, Elpemer GL 2467 SM-DG, Fa. Peters) überzogen. In die Passivierungsschicht werden durch hochenergetische Pulse eines Excimer-Lasers Ausnehmungen 24, 24A bis 24D in den Lack eingebracht, die zur Aufnahme der Biomoleküle 26 dienen. Bei einer Passivierungsschicht mit 15 μm bis 20 μm Dicke benötigt man zum Entfernen des Lacks und zum kurzfristigen Aufschmelzen der Oberfläche etwa 130 Pulse a 20 ns eines Excimer-Lasers (Lambda Physics) mit einer Flächenleistung von 600 - 1200 mJ/cm2. Das Aufschmelzen der Oberfläche führt zum Verschluss von Oberflächenporen der Goldschicht, zu einer Reduktion der Oberflächenrauigkeit und durch Ablation weniger Goldlagen zum Entfernen von Oberflächenverunreinigungen. Die Laser-Bestrahlung des Substrats kann direkt oder über eine Optik bzw. Maske erfolgen und ermöglicht Ausnehmungen beliebiger Größe und Geometrie.The entire conductor pattern is covered with a 15 μm to 20 μm thick passivation layer 22 (FIG. 2 b) made of structurable, optically curable lacquer (2-component solder resist, Elpemer GL 2467 SM-DG, from Peters). Recesses 24, 24A to 24D are made in the passivation layer by high-energy pulses from an excimer laser and are used to hold the biomolecules 26. With a passivation layer with a thickness of 15 μm to 20 μm, you need to remove the lacquer and melt it for a short time Surface about 130 pulses of 20 ns from an excimer laser (Lambda Physics) with an area performance of 600 - 1200 mJ / cm 2 . The melting of the surface leads to the closure of surface pores of the gold layer, to a reduction in the surface roughness and, by ablation, fewer gold layers to the removal of surface impurities. The laser irradiation of the substrate can take place directly or via an optic or mask and enables recesses of any size and geometry.
Figur 2b zeigt einen Schnitt durch ein Leiterbahnsubstrat mit 3 gleichen Spots. Jede der Leiterbahnen 20 besteht aus einem Kupferkern 14, der durchgehend von einer Nickel-Sperrschicht 16 und einer Goldschicht 18 überzogen ist. Im Ausführungsbeispiel hat der Kupferkern eine Dicke von etwa 28 μm. Er stellt einen preiswerten und gut leitfähigen Grundbestandteil der Leiterbahnen dar. Um sehr genaue Messungen bei der elektrochemischen Detektion im wässrigen Medium zu ermöglichen, ist der unedle Kupferkern mit einer 6 μm dicken, durchgehenden Nickelschicht als Diffusionssperre überzogen. Auf dieser Nickel-Schicht wird eine 2 μm dicke Goldschicht aufgebracht.FIG. 2b shows a section through a conductor track substrate with 3 identical spots. Each of the conductor tracks 20 consists of a copper core 14 which is continuously covered by a nickel barrier layer 16 and a gold layer 18. In the exemplary embodiment, the copper core has a thickness of approximately 28 μm. It represents an inexpensive and highly conductive basic component of the conductor tracks. In order to enable very precise measurements during electrochemical detection in an aqueous medium, the base copper core is coated with a 6 μm thick, continuous nickel layer as a diffusion barrier. A 2 μm thick gold layer is applied to this nickel layer.
Die Leiterbahnen des Ausführungsbeispiels sind etwa 150 μm breit und mit einem Abstand von etwa 200 μm (Mitte-Mitte) auf der Trägerplatte angeordnet. Die Arbeitselektroden, die Gegenelektrode und eine gegebenenfalls vorgesehene Referenzelektrode sind zur Kontaktierung jeweils mit nicht dargestellten Anschlusskontaktflächen des elektrischen Substrats verbunden.The conductor tracks of the exemplary embodiment are approximately 150 μm wide and are arranged on the carrier plate at a distance of approximately 200 μm (center-center). The working electrodes, the counter electrode and a reference electrode, if provided, are each connected to connection contact surfaces (not shown) of the electrical substrate for contacting.
In den Ausführungsbeispielen haben die Leiterbahnen kreisrunde Ausnehmungen mit Durchmessern von 10 μm, 30 μm, 100 μm und rechteckige Ausnehmungen der Dimension 100 μm x 700 μm (vgl. 24A bis 24D in Figur 2a). Diese Ausnehmungen weisen also Flächen von 78,5 μm2, 706,5 μm2, 7850 μm2 bzw. 70000 μm2 auf, so dass die aktive Fläche der Elektroden um etwa einen Faktor 1000 variiert wird. Beispiel 2: Funktionalisierung der Spots des Substrats mit Nukleinsäure- Oligomeren.In the exemplary embodiments, the conductor tracks have circular recesses with diameters of 10 μm, 30 μm, 100 μm and rectangular recesses with the dimensions 100 μm × 700 μm (cf. 24A to 24D in FIG. 2a). These recesses thus have areas of 78.5 μm 2 , 706.5 μm 2 , 7850 μm 2 or 70000 μm 2 , so that the active area of the electrodes is varied by a factor of 1000. Example 2: Functionalization of the spots of the substrate with nucleic acid oligomers.
Die im Beispiel 1 beschriebenen freien Substratstellen verschiedener Größe werden z.B. über ein Spotting-Verfahren mit den Nukleinsäure-Oligomeren funktionalisiert.The free substrate sites of various sizes described in Example 1 are e.g. functionalized with the nucleic acid oligomers via a spotting method.
Die Synthese der Oligonukleotide erfolgt in einem automatischen Oligonukleotid- Synthesizer (Expedite 8909; ABI 384 DNA/RNA-Synthesizer) gemäß der vom Hersteller empfohlenen Syntheseprotokolle für eine 1.0 μmol Synthese. Bei den Synthesen mit dem 1-O-Dimethoxytrityl-propyl-disulfid-CPG-Träger (Glen Research 20-2933) werden die Oxidationsschritte mit einer 0.02 mol/l lodlösung durchgeführt, um eine oxidative Spaltung der Disulfidbrücke zu vermeiden. Modifikationen an der 5'-Position der Oligonukleotide erfolgen mit einem auf 5 min verlängerten Kopplungsschritt. Der Amino-Modifier C2 dT (Glen Research 10-1037) wird in die Sequenzen nach dem jeweiligen Standardprotokoll eingebaut. Die Kopplungseffizienzen werden während der Synthese online über die DMT-Kationen- Konzentration photometrisch bzw. konduktometrisch bestimmt.The oligonucleotides are synthesized in an automatic oligonucleotide synthesizer (Expedite 8909; ABI 384 DNA / RNA synthesizer) in accordance with the synthesis protocols recommended by the manufacturer for a 1.0 μmol synthesis. In the syntheses with the 1-O-dimethoxytrityl-propyl-disulfide-CPG carrier (Glen Research 20-2933), the oxidation steps are carried out with a 0.02 mol / l iodine solution in order to avoid oxidative cleavage of the disulfide bridge. Modifications to the 5'-position of the oligonucleotides are carried out with a coupling step which is extended to 5 min. The amino modifier C2 dT (Glen Research 10-1037) is incorporated into the sequences according to the respective standard protocol. The coupling efficiencies are determined online during the synthesis via the DMT cation concentration photometrically or conductometrically.
Die Oligonukleotide werden mit konzentriertem Ammoniak (30%) bei 37°C 16 h entschützt. Die Reinigung der Oligonukleotide erfolgt mittels RP-HPL Chromatographie nach Standardprotokollen (Laufmittel: 0.1 mol/l Triethylammoniumacetat-Puffer, Acetonitril), die Charakterisierung mittels MALDI- TOF MS. Die aminmodifizierten Oligonukleotide werden an die aktivierten Redox- Label (z.B. Osmium-Komplexe) entsprechend den dem Fachmann bekannten Bedingungen gekoppelt. Die Kopplung kann sowohl vor als auch nach der Anbindung der Oligonukleotide an die Oberfläche erfolgen.The oligonucleotides are deprotected with concentrated ammonia (30%) at 37 ° C for 16 h. The oligonucleotides are purified using RP-HPL chromatography according to standard protocols (eluent: 0.1 mol / l triethylammonium acetate buffer, acetonitrile), and the characterization is carried out using MALDI-TOF MS. The amine-modified oligonucleotides are coupled to the activated redox labels (e.g. osmium complexes) in accordance with the conditions known to the person skilled in the art. The coupling can take place both before and after the oligonucleotides have been bound to the surface.
Die Substrate aus dem Beispiel 1 werden z.B. mit doppelt modifiziertem 20 bp Einzelstrang-Oligonukleotid der Sequenz 5'-AGC GGA TAA CAC AGT CAC CT-3' (Modifikation eins: die Phosphatgruppe des 3' Endes ist mit (HO-(CH2)2-S)2 zum P- O-(CH2)2-S-S-(CH2)2-OH verestert. Modifikation zwei: an das amino-modifizierte 5' Ende ist der Osmium-Komplex [Os(bipy)2 Cl imidazolacrylsäure] nach dem jeweiligen Standardprotokoll eingebaut) als 5x10"5 molare Lösung in Puffer (Phosphatpuffer, 0.5 molar in Wasser, pH 7 mit 0.05 vol% SDS) mit Hilfe eines Spotters (Carthesian) aufgebracht und für 2 - 24 h inkubiert.The substrates from Example 1 are, for example, modified with double-modified 20 bp single-strand oligonucleotide of the sequence 5'-AGC GGA TAA CAC AGT CAC CT-3 '(modification one: the phosphate group of the 3' end is with (HO- (CH 2 ) 2 -S) 2 esterified to P- O- (CH 2 ) 2 -SS- (CH 2 ) 2 -OH Modification two: at the amino-modified 5 'end is the osmium complex [Os (bipy) 2 Cl imidazole acrylic acid] according to the respective standard protocol) as a 5x10 "5 molar solution in buffer (Phosphate buffer, 0.5 molar in water, pH 7 with 0.05 vol% SDS) applied using a spotter (Carthesian) and incubated for 2 - 24 h.
Während dieser Reaktionszeit wird der Disulfidspacer P-O-(CH2)2-S-S-(CH2)2-OH des Oligonukleotids homolytisch gespalten. Dabei bildet der Spacer mit Au-Atomen der Oberfläche eine kovalente Au-S Bindung aus, wodurch es zu einer 1 :1 Koadsorption des ss-Oligonukleotids und des abgespaltenen 2-Hydroxy- mercaptoethanols kommt. Statt des Einzelstrang-Oligonukleotids kann der Einzelstrang auch mit seinem Komplementärstrang hybridisiert sein.During this reaction time, the disulfide spacer PO- (CH 2 ) 2 -SS- (CH 2 ) 2 -OH of the oligonucleotide is cleaved homolytically. The spacer forms a covalent Au-S bond with the Au atoms on the surface, which leads to a 1: 1 coadsorption of the ss-oligonucleotide and the split off 2-hydroxy-mercaptoethanol. Instead of the single-stranded oligonucleotide, the single-strand can also be hybridized with its complementary strand.
Für die Belegung mit dem Spotter der Firma Cartesian Technologies (MicroSys PA) werden Split-Pin Nadeln (Arraylt Chipmarker Pins der Firma TeleChem) verwendet, die ein Ladevolumen von 0.2 bis 0.6 μl haben und Volumina von etwa 1 nl pro Benetzungsvorgang abgeben. Die Kontaktfläche dieser Nadeln hat einen Durchmesser von etwa 130 μm und ist damit deutlich größer als die bei der Laser- Ablation freigelegten Bereiche des Substrates. Die Positionierung der Nadel über dem Substrat erfolgt mit einer Genauigkeit von 10 μm bei einer Luftfeuchtigkeit von etwa 70 - 80%. Der Tropfen wird beim Kontakt der Spitze mit der Passivierungsschicht abgegeben und es kommt zu keiner direkten Berührung mit dem Substrat („Pseudo-Kontakt-Drucken").Split-pin needles (Arraylt chipmarker pins from TeleChem) are used for the assignment with the spotter from Cartesian Technologies (MicroSys PA), which have a loading volume of 0.2 to 0.6 μl and deliver volumes of about 1 nl per wetting process. The contact area of these needles has a diameter of approximately 130 μm and is therefore significantly larger than the areas of the substrate exposed during laser ablation. The needle is positioned over the substrate with an accuracy of 10 μm at a humidity of around 70 - 80%. The drop is released when the tip comes into contact with the passivation layer and there is no direct contact with the substrate (“pseudo-contact printing”).
Beispiel 3: Variation der Oberflächenbelegung durch Koadsorbate.Example 3: Variation of the surface coverage by coadsorbates.
Die Belegungsdichte eines Spots mit Nukleinsäure-Oligomeren lässt sich durch die Koadsorption mit Thiolen kontrolliert reduzieren, um somit den relativen Anteil von Bindungsereignissen bei gleich bleibender Target-Konzentration und Elektrodengröße zu erhöhen.The occupancy density of a spot with nucleic acid oligomers can be reduced in a controlled manner by coadsorption with thiols, in order to increase the relative proportion of binding events with the target concentration and electrode size remaining the same.
Für die Koadsorption von Thiolen stehen zwei Verfahren zur Wahl. In einem Verfahren besteht die Inkubationslösung aus den Nukleinsäure-Oligomeren (analog Beispiel 2) mit zusätzlich zwischen ca. 10"5 bis 10'1 molarem Propanthiol. Dieses gleichzeitig anwesende, freie Propanthiol wird durch Ausbildung einer Au-S Bindung koadsorbiert und beansprucht somit Platz auf der Sensoroberfläche. Bei einem alternativen Verfahren wird das Propanthiol (10"5 bis 10"1 molar in 500 mmol/l Phosphat-Puffer) in einem zweiten Inkubationsschritt (30 min bis 12 h) nach der Funktionalisierung der Sensoroberfläche mit Nukleinsäure-Oligomeren aufgebracht.Two methods are available for the co-adsorption of thiols. In one process, the incubation solution consists of the nucleic acid oligomers (analogous to Example 2) with an additional between about 10 "5 to 10 '1 molar propanethiol. This free propanethiol, which is present at the same time, is co-adsorbed by forming an Au-S bond and thus takes up space on the sensor surface alternative methods, the propanethiol (10 "5 to 10 " 1 molar in 500 mmol / l phosphate buffer) is applied in a second incubation step (30 min to 12 h) after the functionalization of the sensor surface with nucleic acid oligomers.
Durch die Verwendung von Propanthiol als Koadsorbat kann die Oberflächenbelegungsdichte der Nukleinsäure-Oligomere in beiden Varianten um bis zu einem Faktor 10 reduziert werden.The use of propanethiol as a coadsorbate can reduce the surface coverage density of the nucleic acid oligomers in both variants by up to a factor of 10.
Beispiel 4: Variation der Oberflächenbelegung durch Belegungsparameter.Example 4: Varying the surface occupancy using occupancy parameters.
Auch durch die Variation ausgewählter Belegungsparameter bei der Funktionalisierung mit Nukleinsäure-Oligomeren lässt sich die Oberflächenbelegungsdichte der Spots des Sensors einstellen.The surface coverage density of the sensor spots can also be adjusted by varying selected occupancy parameters when functionalizing with nucleic acid oligomers.
Erhöht man z.B. die Konzentration der Nukleinsäure-Oligomere in der Inkubationslösung (500 mmol/l Puffer) von 1 μmol/l auf 30 μmol/l, so steigt' die Belegungsdichte um einen Faktor 5. Eine ähnliche Erhöhung der Oberflächenbelegung erhält man, wenn die Konzentration des Inkubationspuffers von 10 mmol/l auf 500 mmol/l bei einer Sonden-Konzentration von 30 μmol/l erhöht wird.If you increase e.g. the concentration of the nucleic acid oligomers in the incubation solution (500 mmol / l buffer) from 1 μmol / l to 30 μmol / l, the occupancy density increases by a factor of 5. A similar increase in the surface coverage is obtained when the concentration of the incubation buffer is increased from 10 mmol / l to 500 mmol / l at a probe concentration of 30 μmol / l.
Beispiel 5: Hybridisierung mit komplementären Nukleinsäure-Oligomeren.Example 5: Hybridization with complementary nucleic acid oligomers.
Ein Substrat mit 48 Arbeitselektroden wird wie in Beispiel 1 beschrieben mit aktiven Bereichen verschiedener Größen hergestellt. In Gruppen von je 12 Elektroden werden mit dem Excimer-Laser kreisrunde Löcher mit einem Durchmesser von 10 μm (Spotgruppe 1), 30 μm (Spotgruppe 2) bzw. 100 μm (Spotgruppe 3) und ein rechteckiges Profil mit 100 μm x 700 μm (Spotgruppe 4) gebrannt. Die einzelnen Spotgruppen weisen also Flächen von 78,5 μm2, 706,5 μm2, 7850 μm2 bzw. 70000 μm2 auf, so dass die Fläche um einen Faktor von rund 1000 variiert wird. Die Arbeitselektroden einer Spotgruppe werden jeweils mit doppelt modifizierten Nukleinsäure-Oligomeren (Sonden) einer bestimmten Sequenz (S1 bis S4) analog dem Beispiel 2 funktionalisiert. Die Arbeitselektroden weisen annähernd die gleichen Oberflächenbelegungsdichten auf. Figur 3 zeigt exemplarisch eine ACV- Messung (Uac = 10 mV, f = 5 Hz) einer Arbeitselektrode (Symbole □ in Figur 3), die mit Osmium-modifizierten Oligomeren funktionalisiert ist. Aus dem Redox-Strom am Potential des Osmium-Komplexes lässt sich die Oberflächenbelegungsdichte mit Nukleinsäure-Oligomeren berechnen. Im vorliegenden Fall ergibt sich ein Wert von 5 x 10"1 mol/cm2.A substrate with 48 working electrodes is produced as described in Example 1 with active areas of different sizes. In groups of 12 electrodes each, circular holes with a diameter of 10 μm (spot group 1), 30 μm (spot group 2) or 100 μm (spot group 3) and a rectangular profile with 100 μm x 700 μm ( Spot group 4) burned. The individual spot groups therefore have areas of 78.5 μm 2 , 706.5 μm 2 , 7850 μm 2 or 70000 μm 2 , so that the area is varied by a factor of around 1000. The working electrodes of a spot group are each functionalized with double-modified nucleic acid oligomers (probes) of a certain sequence (S1 to S4) analogously to Example 2. The working electrodes have approximately the same surface coverage densities. Figure 3 shows an example of an ACV measurement (U ac = 10 mV, f = 5 Hz) of a working electrode (symbols □ in Figure 3), which is functionalized with osmium-modified oligomers. The surface coverage density with nucleic acid oligomers can be calculated from the redox current at the potential of the osmium complex. In the present case, the result is 5 x 10 "1 mol / cm 2 .
Nach der Funktionalisierung werden die Arbeitselektroden noch vor der Hybridisierung mit komplementären, Ferrocen-modifizierten Nukleinsäure- Oligomeren in einem Nachbelegungsschritt für 30 Minuten mit einer 1 mmol/l Lösung Propanthiol in Kontakt gebracht. Hierbei werden die Räume zwischen den Nukleinsäure-Oligomeren hydrophobisiert. Dadurch verschiebt sich das Redoxpotential des Ferrocens zu positiveren Werten, wodurch eine bessere Separation vom Osmium-Potential erreicht wird.After the functionalization, the working electrodes are brought into contact with complementary, ferrocene-modified nucleic acid oligomers in a post-loading step for 30 minutes with a 1 mmol / l solution of propanethiol before hybridization. The spaces between the nucleic acid oligomers are rendered hydrophobic. This shifts the redox potential of ferrocene to more positive values, resulting in better separation from the osmium potential.
Die vier unterschiedlichen Target-Nukleinsäure-Oligomere werden analog Beispiel 2 aber ohne Thiol-Modifikation am 3' Ende synthetisiert. Die Target-Nukleinsäure- Oligomere weisen eine zu jeweils einem Sonden-Nukleinsäure-Oligomer komplementäre Sequenz (T1 bis T4) auf. Für die Modifikation mit dem Redox-Label Ferrocen werden die amino-modifizierten Nukleinsäure-Oligomere am 5' Ende mit Ferrocenessigsäure (FcAc) gemäß dem jeweiligen Standardprotokoll gekoppelt.The four different target nucleic acid oligomers are synthesized analogously to Example 2 but without a thiol modification at the 3 'end. The target nucleic acid oligomers have a sequence (T1 to T4) which is complementary to a probe nucleic acid oligomer. For the modification with the redox label ferrocene, the amino-modified nucleic acid oligomers are coupled at the 5 'end with ferrocene acetic acid (FcAc) in accordance with the respective standard protocol.
Die 4 verschiedenen Ferrocen-modifizierten Nukleinsäure-Oligomere werden der Target-Lösung in unterschiedlichen Konzentrationen (T1 = 0.1 μmol/I, T2 = 1 μmol/l, T3 = 10 μmol/l, T4 = 100 μmol/l in 500 mmol/l Phosphat-Puffer, pH 7, mit 1 mol/l NaCI und 0.05 vol% SDS) zugegeben und auf alle Spots des Sensors aufgebracht. Nach einer gewissen Inkubationszeit unter hybridisierenden Bedingungen wird das Substrat gespült und erneut eine elektrochemische ACV-Messung (Uac = 10 mV, f = 5 Hz) durchgeführt (Symbole ■ in Figur 3). Die Messdaten zeigen einen zweiten Redox-Peak, wobei das Verhältnis der Peak-Ströme des Osmium-Labels und des Ferrocen-Labels der Hybridisierungs-Effizienz des Experiments entspricht. Die Messdaten der Hybridisierung aus Figur 3 zeigen eine Elektrode nahe der Sättigung mit einer Hybridisierungseffizienz von über 90 %. Die Arbeitselektroden mit den auf die Konzentrationen der jeweiligen Targets angepassten Größen zeigen hingegen alle die gleichen Hybridisierungs-Effizienzen von etwa 30 - 40 %.The 4 different ferrocene-modified nucleic acid oligomers are the target solution in different concentrations (T1 = 0.1 μmol / I, T2 = 1 μmol / l, T3 = 10 μmol / l, T4 = 100 μmol / l in 500 mmol / l Phosphate buffer, pH 7, with 1 mol / l NaCl and 0.05 vol% SDS) added and applied to all spots of the sensor. After a certain incubation period under hybridizing conditions, the substrate is rinsed and an electrochemical ACV measurement (U ac = 10 mV, f = 5 Hz) is carried out again (symbols ■ in FIG. 3). The measurement data show a second redox peak, the ratio of the peak currents of the osmium label and the ferrocene label corresponding to the hybridization efficiency of the experiment. The measurement data of the hybridization from FIG. 3 show an electrode close to saturation with a hybridization efficiency of over 90%. In contrast, the working electrodes with the sizes adapted to the concentrations of the respective targets all show the same hybridization efficiencies of approximately 30-40%.
Beispiel 6: Diagnostik-Chip.Example 6: Diagnostic chip.
In der medizinischen Diagnostik ist es wünschenswert, mehrere diagnostisch relevante Parameter gleichzeitig bei einer Untersuchung zu erfassen. Ein wichtiges Beispiel aus dem Bereich der Routineuntersuchungen ist ein Vaginalabstrich, der unter anderem auf HPV, E-Coli und Laktobazillen untersucht wird. Bei einem solchen Abstrich wird mit Hilfe von standardisierten Tupfern eine Probe entnommen, die dann mit genormten Verfahren behandelt wird, um die RNA der vorhandenen Bakterien und die doppelsträngige DNA der Viren zu erhalten. Bei einer Untersuchung werden Keim- bzw. Partikelzahlen bis zu einer gewissen Grenze als unbedenklich eingestuft: Bei HPV sind dies 100 Partikel, bei E-coli 100 Keime und bei Laktobazillen 10000 Keime aller relevanten Laktobazillen. Da in Bakterienzellen die charakteristischen RNAs jeweils etwa 104-fach vorkommen, muss ein parallelisierter Chip-Test sehr unterschiedliche Konzentrationen erfassen können, um alle Parameter gleichzeitig bei einer Untersuchung zu erhalten. Ein erfindungsgemäßer Sensor-Chip für obige Anwendung hat drei verschiedene Spotgrößen, die mit für die jeweiligen Krankheits-Targets spezifischen Sonden- Polynukleotiden funktionalisiert sind. Zum Nachweis der HPV-DNA im Bereich von 102 bis 104 Molekülen in der Testsubstanz werden Spots mit einer Fläche von 1 μm2 verwendet, während für die E-Coli-RNA im Bereich von 106 bis 108 Molekülen (entsprechend 102 bis 104 Keimen) Flächen von 104 μm2 und für die Laktobazillen- RNA im Bereich von 108 bis 1010 Molekülen (entsprechend 104 bis 106 Keimen) Flächen von 106 μm2 benutzt werden. Durch die Wahl der Elektrodengrößen wird gewährleistet, dass der Sensor für den jeweiligen Bereich ab den kritischen Target- Konzentrationen der verschiedenen Erreger quantitative Messungen zulässt und somit eine parallele Diagnose aller Krankheiten getroffen werden kann. In medical diagnostics, it is desirable to record several diagnostically relevant parameters at the same time during an examination. An important example from the field of routine examinations is a vaginal smear, which is examined for HPV, E-Coli and lactobacilli, among others. In the case of such a smear, a sample is taken with the aid of standardized swabs, which is then treated using standardized methods in order to obtain the RNA of the bacteria present and the double-stranded DNA of the viruses. In an investigation, bacteria or particle numbers up to a certain limit are classified as harmless: for HPV this is 100 particles, for E-coli 100 germs and for lactobacilli 10000 germs of all relevant lactobacilli. Since the characteristic RNAs are found approximately 10 4 -fold in bacterial cells, a parallelized chip test must be able to detect very different concentrations in order to obtain all parameters simultaneously during an examination. A sensor chip according to the invention for the above application has three different spot sizes, which are functionalized with probe polynucleotides specific for the respective disease targets. Spots with an area of 1 μm 2 are used to detect the HPV-DNA in the range of 10 2 to 10 4 molecules in the test substance, while for the E-Coli RNA in the range of 10 6 to 10 8 molecules (corresponding to 10 2 up to 10 4 germs) areas of 10 4 μm 2 and for the lactobacillus RNA in the range of 10 8 to 10 10 molecules (corresponding to 10 4 to 10 6 germs) areas of 10 6 μm 2 are used. The choice of the electrode sizes ensures that the sensor for the respective area allows quantitative measurements from the critical target concentrations of the different pathogens and thus a parallel diagnosis of all diseases can be made.

Claims

Patentansprüche claims
1. Substrat zum Einsatz als Träger von Ligaten bei einem Verfahren zur Detektion von Ligat-Ligand-Assoziationsereignissen, mit auf dem Substrat angeordneten1. Substrate for use as a carrier of ligates in a method for the detection of ligate-ligand association events, arranged on the substrate
Teststellen (24) und mit an die Oberfläche der Teststellen (24) gebundenen Ligaten (26), wobei wenigstens zwei Arten von Teststellen (24) vorgesehen sind, wobei die verschiedenen Arten von Teststellen jeweils mit verschiedenen Arten von Ligaten (26) belegt sind, wobei durch die verschiedenen Arten von Ligaten (26) jeweils komplementäre Arten von Liganden detektiert werden, wobei die Liganden in einer Analytlösung in jeweils unterschiedlichen Konzentrationsbereichen vorliegen, und wobei die Teststellen (24) einen charakteristischen Belegungsparameter aufweisen, der eine Detektion der Liganden in deren jeweiligen Konzentrationsbereich erlaubt.Test sites (24) and with ligates (26) bound to the surface of the test sites (24), at least two types of test sites (24) being provided, the different types of test sites each being occupied with different types of ligates (26), whereby the different types of ligates (26) each detect complementary types of ligands, the ligands being present in an analyte solution in different concentration ranges, and wherein the test sites (24) have a characteristic occupancy parameter that enables detection of the ligands in their respective Concentration range allowed.
2. Substrat nach Anspruch 1 , wobei der charakteristische Belegungsparameter die Fläche der Teststellen ist.2. Substrate according to claim 1, wherein the characteristic occupancy parameter is the area of the test sites.
3. Substrat nach Anspruch 2, wobei sich die Fläche der Teststellen (24) um mindestens den Faktor 10 unterscheidet.3. The substrate of claim 2, wherein the area of the test sites (24) differs by at least a factor of 10.
4. Substrat nach Anspruch 2, wobei sich die Fläche der Teststellen (24) um mindestens den Faktor 100 unterscheidet.4. The substrate of claim 2, wherein the area of the test sites (24) differs by at least a factor of 100.
5. Substrat nach Anspruch 2, wobei sich die Fläche der Teststellen (24) um mindestens den Faktor 1000 unterscheidet.5. The substrate of claim 2, wherein the area of the test sites (24) differs by at least a factor of 1000.
6. Substrat nach Anspruch 2, wobei sich die Fläche der Teststellen (24) um mindestens den Faktor 10000 unterscheidet.6. The substrate of claim 2, wherein the area of the test sites (24) differs by at least a factor of 10,000.
7. Substrat nach einem der Ansprüche 2 bis 6, wobei die Fläche der Teststellen (24) zwischen 1 μm2 und 10 mm2 beträgt. 7. Substrate according to one of claims 2 to 6, wherein the area of the test sites (24) is between 1 μm 2 and 10 mm 2 .
8. Substrat nach Anspruch 7, wobei die Fläche der Teststellen (24) zwischen 10 μm2 und 100000 μm2 beträgt.8. The substrate according to claim 7, wherein the area of the test sites (24) is between 10 μm 2 and 100000 μm 2 .
9. Substrat nach einem der vorhergehenden Ansprüche, wobei der charakteristische Belegungsparameter die Belegungsdichte der Teststellen mit9. Substrate according to one of the preceding claims, wherein the characteristic occupancy parameter includes the occupancy density of the test sites
Ligaten ist.Is ligates.
10. Substrat nach Anspruch 9, wobei sich die Belegungsdichte der Teststellen (24) mit Ligaten um mindestens den Faktor 10 unterscheidet.10. The substrate of claim 9, wherein the occupancy density of the test sites (24) with ligates differs by at least a factor of 10.
11. Substrat nach Anspruch 9, wobei sich die Belegungsdichte der Teststellen (24) mit Ligaten um mindestens den Faktor 100 unterscheidet.11. The substrate of claim 9, wherein the coverage density of the test sites (24) with ligates differs by at least a factor of 100.
12. Substrat nach Anspruch 9, wobei sich die Belegungsdichte der Teststellen (24) mit Ligaten um mindestens den Faktor 500 unterscheidet.12. The substrate of claim 9, wherein the occupancy density of the test sites (24) with ligates differs by at least a factor of 500.
13. Substrat nach einem der vorhergehenden Ansprüche, wobei sich die jeweiligen Mittelwerte der Konzentrationsbereiche, in denen die verschiedenen Arten von Liganden vorliegen, um wenigstens einen Faktor 10 unterscheiden.13. Substrate according to one of the preceding claims, wherein the respective mean values of the concentration ranges in which the different types of ligands are present differ by at least a factor of 10.
14. Substrat nach Anspruch 13, wobei sich die jeweiligen Mittelwerte der Konzentrationsbereiche, in denen die verschiedenen Arten von Liganden vorliegen, um wenigstens einen Faktor 100 unterscheiden.14. The substrate according to claim 13, wherein the respective mean values of the concentration ranges in which the different types of ligands are present differ by at least a factor of 100.
15. Substrat nach Anspruch 13, wobei sich die jeweiligen Mittelwerte der Konzentrationsbereiche, in denen die verschiedenen Arten von Liganden vorliegen, um wenigstens einen Faktor 1000 unterscheiden.15. The substrate according to claim 13, wherein the respective mean values of the concentration ranges in which the different types of ligands are present differ by at least a factor of 1000.
16. Substrat nach Anspruch 13, wobei sich die jeweiligen Mittelwerte der Konzentrationsbereiche, in denen die verschiedenen Arten von Liganden vorliegen, um wenigstens einen Faktor 10000 unterscheiden. 16. The substrate according to claim 13, wherein the respective mean values of the concentration ranges in which the different types of ligands are present differ by at least a factor of 10,000.
17. Substrat nach einem der vorhergehenden Ansprüche, wobei als Liganden Cofaktoren oder Coenzyme und als Ligaten Proteine oder Enzyme verwendet werden.17. Substrate according to one of the preceding claims, wherein cofactors or coenzymes are used as ligands and proteins or enzymes are used as ligates.
18. Substrat nach einem der Ansprüche 1 bis 16, wobei als Liganden Antikörper und als Ligaten Antigene verwendet werden.18. Substrate according to one of claims 1 to 16, wherein antibodies are used as ligands and antigens are used as ligates.
19. Substrat nach einem der Ansprüche 1 bis 16, wobei als Liganden Antigene und als Ligaten Antikörper verwendet werden.19. Substrate according to one of claims 1 to 16, wherein antigens are used as ligands and antibodies are used as ligates.
20. Substrat nach einem der Ansprüche 1 bis 16, wobei als Liganden Rezeptoren und als Ligaten Hormone verwendet werden.20. Substrate according to one of claims 1 to 16, wherein receptors are used as ligands and hormones are used as ligates.
21. Substrat nach einem der Ansprüche 1 bis 16, wobei als Liganden Hormone und als Ligaten Rezeptoren verwendet werden.21. Substrate according to one of claims 1 to 16, wherein hormones are used as ligands and receptors are used as ligates.
22. Substrat nach einem der Ansprüche 1 bis 16, wobei als Liganden Nukleinsäure- Oligomere und als Ligaten dazu komplementäre Nukleinsäure-Oligomere verwendet werden.22. Substrate according to one of claims 1 to 16, wherein nucleic acid oligomers are used as ligands and nucleic acid oligomers complementary thereto are used as ligates.
23. Substrat nach einem der vorhergehenden Ansprüche, wobei das Substrat mit einer Passivierungsschicht belegt ist, die an den Teststellen (24) Aussparungen aufweist.23. Substrate according to one of the preceding claims, wherein the substrate is covered with a passivation layer which has cutouts at the test sites (24).
24. Verwendung eines Substrats nach einem der vorhergehenden Ansprüche in einem Verfahren zur Detektion von Ligat-Ligand-Assoziationsereignissen.24. Use of a substrate according to one of the preceding claims in a method for the detection of ligate-ligand association events.
25. Verwendung nach Anspruch 24, wobei es sich um ein elektrochemisches Nachweisverfahren handelt ausgewählt aus der Gruppe Chronoamperometrie (CA), Chronocoulometrie (CC), Linear Sweep Voltammetrie (LSV), zyklische25. Use according to claim 24, wherein it is an electrochemical detection method selected from the group chronoamperometry (CA), chronocoulometry (CC), linear sweep voltammetry (LSV), cyclic
Voltammetrie (CSV), Alternating current voltammetry (ACV), Voltammetrietechniken mit verschiedenen Pulsformen, insbesondere Square Wave Voltammetrie (SWV), Differential Pulse Voltammetrie (DPV) oder Normal Pulse Voltammetrie (NPV), AC oder DC Impedanzspektroskopie, Chronopotentiometrie und zyklische Chronopotentiometrie.Voltammetry (CSV), alternating current voltammetry (ACV), voltammetry techniques with different pulse shapes, in particular square wave voltammetry (SWV), differential pulse voltammetry (DPV) or normal Pulse voltammetry (NPV), AC or DC impedance spectroscopy, chronopotentiometry and cyclic chronopotentiometry.
26. Verwendung nach Anspruch 24, wobei es sich um ein fluoreszenzspektroskopisches Nachweisverfahren handelt. 26. Use according to claim 24, wherein it is a fluorescence spectroscopic detection method.
EP04731631A 2003-05-06 2004-05-07 Substrate in the form of a ligate carrier Withdrawn EP1656556A2 (en)

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DE10320312A DE10320312A1 (en) 2003-05-06 2003-05-06 Substrate as a carrier for ligates
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WO2006113785A2 (en) * 2005-04-18 2006-10-26 Brigham Young University Laser modification and functionalization of substrates
WO2006114249A1 (en) * 2005-04-26 2006-11-02 Bayer Technology Services Gmbh Novel equipment and method for coating substrates for analyte detection by way of an affinity assay method

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