WO2004092250A1 - Biocompatible material - Google Patents

Abstract

The invention relates to biocompatible optical material wherein biological molecules can be incorporated. The material can be processed in low temperatures and substantially neutral pH conditions to ensure the survival of the incorporated biomolecules.

Description

Biocompatible material

FIELD OF INVENTION

The invention relates to biocompatible optical material wherein biological molecules can be incorporated. The material can be processed in low temperatures and substantially neutral pH conditions to ensure the survival of the incorporated biomolecules.

DESCRIPTION OF RELATED ART

Recently, the interest for sensors for biological applications such as diagnostics, studying protein-protein interactions or interactions of proteins or other biological molecules, such as DNA, RNA, lipids and pharmacological molecules with each other, or control of industrial processes such as fermentation or chromatography, has been increased markedly. Ideally this kind of sensor would be very sensitive, free of labeling of the analytes and it should yield results quickly. Furthermore, ideal apparatus for aforementioned applications should also have the capability to be multiplexed to achieve high throughput rate. At the same time applications for home and bedside diagnostic areas require analyzing methods that are easy to use and inexpensive to manufacture.

Analytical microarray systems are being looked to more and more as a viable means for meeting the increased requirements to increase the throughput rate and decrease the time of analysis. However, the complex chemical nature of proteins has made the development of protein microarray systems more challenging than that of gene chips. The array must be robust but at the same time the contact with the receptor and the chip surface must not interfere with the binding of the receptor to its ligand. A common way to recognize the binding of the analyte to its receptor is to detect a label attached to the analyte. The label may be for example fluorescent, luminescent or radioactive label or other kind of tag. Alternatively, a known amount of a molecule competing with the analyte for binding to same receptor is labeled and added to the sample. The intensity of fluorescent or other type of labels can be measured after non-specific labeled molecules have been removed by washing. (Schweitzer B, Kingsmore SF, Measuring proteins on microarrays. Curr Opin Biotechnol 2002 Feb; 13(1): 14-9.) The disadvantages of labeling techniques are the increased time, effort and costs that are associated with the labeling. Furthermore, the methodology is not readily multiplexed to achieve high-throughput analyzing devices.

Direct optical methods that enable label free detection of biological molecules exist, but they have limitations. Such detection methods include surface plasmon resonance (SPR) technology (US 5641640, Cullen, Brown & Lowe, Detection of immuno-complex formation via surface plasmon resonance on gold-coated diffraction gratings. Biosensors 1987-88;3(4):211-25), ellipsometry (Jin et al., Biosensor concept based imaging ellipsometry for visualization of biomolβcular interactions. Analytical Biochemistry, 232:69-72.), reflectometry (Brecht & Gauglitz. Optical probes and transducers. Biosensors and Bioelectronics 10:923- 936), and resonant mirror and grating coupling sensors.

SPR technology relates to an assay of the type wherein the presence of the analyte is detected by determining the change in the refractive index at a solid optical surface. This change is caused by the analyte involving or influencing the binding of a refractive index enhancing species to the optical surface, or release there from, respectively. SPR is observed as a dip in intensity of light reflected at a specific angle from the interface between an optically transparent material (e.g. glass) and a thin metal film, usually silver or gold. SPR depends, among the other factors, on the refractive index of the medium (e.g. a sample solution) close to the metal surface. A change of refractive index at the metal surface, such as by the adsorption or binding of material thereto, will cause a corresponding shift in the angle at which SPR occurs. To couple the light to the interface such that SPR arises, three alternative arrangements are used: a metallized diffraction grating (Wood's effect), or a metallized glass prism or a prism in optical contact with a metallized glass substrate (Kretschmann effect), or metallized waveguide (for example fiber or planar waveguide) based structures (see Jiri Homola, Sinclair S. Yee ,Gϋnter Gauglitz, "Surface plasmon resonance sensors: review" Sensors and Acuators B 54 (1999) 3- 15). US 5313264 describe an optical biosensor system employing the principle of SPR.

SPR assays have certain fundamental limitations that restrict the technical performance thereof. One major limiting factor is the sensitivity, or the signal strength. The SPR response depends on the volume and refractive index of the bound analyte, which volume is limited by mass transfer, reaction kinetic and equilibrium parameters. Since the SPR-measurement response is proportional to the change in refractive index caused, when e.g. protein molecules are adsorbed to the surface and displace water there from, the refractive index difference between the protein and the buffer solution puts a theoretical limit to the strength of the response that may be obtained. SPR-based immunoassays for substances of low molecular weight or substances occurring at low concentrations are problematic due to the very small changes in refractive index caused when the analyte binds to or dissociates from the antibody-coated sensing surface. One disadvantage of SPR technology is that multiplexing is complicated and expensive and no commercially available high-throughput device based on SPR exists. However, arrays for rapid and simultaneous detection of several analytes i.e. multiplexed sensor setups are needed for example in diagnostic applications. The capability to measure multiple different diagnostically relevant values from a clinical sample would have obvious benefits. Said sensor would certainly prove valuable also in research use. Miniaturized DNA arrays have been developed (for example, see US 5,412,087, 5,445,932 and 5,744,305) and are available commercially. Also multiplexed protein microarrays are being developed (for example, see US 6,475,809, and US 6,365,418). However, the detection of the biological molecules (DNA or proteins) is based on labeling the analytes with fluorescent or other labels. Although the miniaturization of said assays increases their throughput rate, the requirement for labeling still set limitations for their use.

Up to date, the available methods for biomolecular recognition have not produced commercially available platforms for high-throughput analysis. Therefore, there is need for new sensitive and low-cost detection technologies.

An object of the present invention is to provide new biocompatible optical materials.

A further object of the present invention is to provide biocompatible materials, which can be processed and handled in conditions that are not harmful for biological molecules, e.g. they are non-denaturing.

A further object of the present invention is to provide new materials for a novel label free analyzing devices and methods for detecting the presence and quantity of an analyte of interest in a sample.

A further object of the present invention is to provide materials for microfluidistic applications. A further object of the present invention is to provide materials for bioactive films and filters. For example bioactive agents can be incorporated to such films and filters.

A further object of the present invention is to provide a sensor device, which can be easily multiplexed to create sensor arrays for simultaneous detection of several analytes. This sensor device preferably utilizes the above-mentioned label- free analyzing method and materials according to the invention.

A further object of the present invention is to provide a sensor device, which can be used in several different types of assays, such as detecting the presence and quantity of different types of biological or pharmaceutical molecules. The detected molecules can be e.g. proteins, DNA or RNA molecules, pharmacological molecules, lipids, carbohydrates, organic or inorganic molecules.

A further object of the present invention is to provide a gentle method for coupling the receptor molecules to the materials used in the sensor device. The method used can be done at relatively low temperatures and in neutral pH conditions. The mild processing conditions ensure the functional preservations of biological material attached to the sensor, allowing flexibility in the device construction. The biological receptors can be attached to the sensor material either before of after the final patterning of the sensor surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a schematic diagram of one embodiment of an optical grating

Fig. 2 shows another embodiment of a grating structure, where the period (d) of the grating can be 6 μm and height Qt₂) 3 μm. The refractive indexes (n and n₂) are different and can be for example 1.514 (n ) and 1.470 (n₂).

Figs. 3A, 3B and 3C show schematic diagrams of biosensors utilizing different grating profiles: binary grating (3A), sinusoidal grating (3B), and blazed grating (3C).

Fig. 4 shows a top view of a biosensor that has an array of patches reactive towards specific analytes arranged in square formation.

Fig. 5 shows a top view of a biosensor that has patches reactive towards specific analytes arranged in circular formation.

Fig. 6 shows binding of an analyte to protein receptor in a single pore in the sensitive layer

Fig. 7 shows binding of an analyte to DNA receptor in a single pore in the sensitive layer

Fig. 8 shows a method for amplifying the effect the analyte binding by using a streptavidin-coated nanoparticle Fig. 9 shows a method that can be used to immobilize a biotinylated receptor to the streptavidin coated sensitive layer

Fig. 10 shows a method that can be used to measure enzyme activity with a biosensor.

Fig. 11 shows examples of the surface chemistry that can be used to immobilize the receptors to the sensor.

Fig. 12 shows an example of a biosensor in a tip of an optical fiber.

Fig. 13 shows an example of multiple biosensors coupled to a waveguide.

Fig. 14 shows a scanning electron microscope photograph of a grating structure that can be used in a biosensor.

Fig. 15 shows a scanning electron microscope photograph of a biosensor after a sensitive layer has been spinned on top of the grating.

Fig. 16 shows an photograph of a biochip which contains biosensors that each have a sensitive area of 3 mm x 3mm.

Fig. 17 shows measurements of transmitted zeroeth-order/first-order light intensity ratios after applying 10 μl of leptin hormone (concentration 1 μg/1) over a biosensor capable of specifically detecting leptin.

Fig. 18 shows a setup that can be used to measure the effects that take place in the sensitive layer of the grating structure. A modulated light source (e.g. laser) can be used to illuminate the grating. Zeroeth and first order light beams are detected using two different light detectors.

Fig. 19 shows an alternative way to measure multiple orders of light beams with one light detector.

Figs. 20 A and 20 B show how zeroeth order light beam can be measured using a lens and a second detector (20 A). The modulation of the light beam can be also made after the grating using a spatial modulator such as chopper (20 B). Herein mentioned modulator can be constracted in a way that only zeroeth order light can pass through to the grating at a time and higher orders of light (but not zeroeth order) at another time.

Fig. 21 shows an example how a CCD row camera can be used to detect multiple orders simultaneously.

Fig. 22 shows an example using a LED or a bulb as a light source providing light to the transmitting optics.

Fig. 23 shows an example of how integrated sphere can be used with LED or bulb sources.

Fig. 24 shows how an integrated sphere can be connected to an optical fiber.

Fig. 25 shows a fiber optical configuration, which uses a fiber pigtailed laser as a source.

Fig. 26 shows an example how light source and transmitting optics can be integrated to a substrate.

Fig. 27 shows an example how an additional grating can be used to divide the zeroeth order beam for further analysis when a wideband source is used.

Fig. 28 shows how prism-grating-prism component can be used to spread the zeroeth order beam into spectrum.

Fig. 29 shows an example of a light source with a scanning filter.

Fig. 30 shows how two or more different light sources may be used with an integrated sphere.

Fig. 31 shows an example how electrically modulated LED's can be used as a light source.

Fig. 32 shows how wide band light source can be used with conventional silicon photodiodes. Fig. 33 illustrates how a biochip can be simultaneously measured using different income angles.

Fig. 34 shows the simulated diffraction efficiencies for zeroeth (TO) and first (TI) transmission orders for TE and TM polarized light as a function of grating modulation depth when grating layer refractive index is 1.600 and sensitive layer refractive index 1.514.

Fig. 35 shows the simulated diffraction efficiencies as function of the change of the refractive index ( ij) of the sensitive layer when grating modulation depth is 2.5 μm.

Fig. 36 shows the change of refractive index (nj) as a function of the ratio of the intensities of the first and zeroeth diffraction orders.

Fig. 37 illustrates a measurement setup that can be used with a biochip.

Fig. 38 shows an example how a biochip can be used to detect multiple analytes with multiple biosensors from one sample.

Fig. 39 shows an example how a biochip can be used to detect an analyte from multiple samples.

Fig. 40 illustrates how microfluidistic channels can be used to deliver a sample to biosensor in a biochip.

DETAILED DESCRIPTION OF THE INVENTION

1) DEFINITIONS

For a better understanding the abbreviations and concepts used hereinbefore and hereinafter are the following:

The word 'receptor' used herein denotes any molecule capable of specifically non-covalently binding the analyte of interest. The receptor molecules can be e.g. biological molecules, such as proteins, peptides, polyclonal or monoclonal antibodies, single chain antibodies (scFv), antibody binding fragments (Fab), antigens, DNA or RNA molecules (nucleic acids), ligands, lipids or carbohydrate molecules or like, pharmacological molecules, small organic molecules, or other organic or inorganic molecules. The receptor molecules can also be cell organelles, viruses, bacteria or cell either in part or in whole. The receptor is attached onto the sensitive layer or it is incorporated into the layer.

The word 'analyte' used herein denotes the molecule or molecule species in the sample, which is to be measured. The analyte can comprise a protein, peptide, antibody, nucleic acid, cellular organelle, virus, bacteria or cell. The analyte can also be or is originated from a biological sample e.g. blood, plasma, serum, gastrointestinal secretions, homogenates of tissues or tumors, synovial fluid, feces, saliva, sputum, cyst fluid, amniotic fluid, cerebrospinal fluid, peritoneal fluid, lung lavage fluid, semen, prostatic fluid, tears or lymphatic fluid. The analyte is applied onto the sensor device.

The word 'grating' used herein denotes an one-dimensional or a two- dimensional optical diffraction grating.

The word 'microarray' used herein denotes a detection platform where multiple sensors capable of detecting different analytes have been miniaturized into a compact device. The word 'biochip' generally has the same meaning.

The word 'biosensor' used herein denotes a single unit comprising a grating and the sensitive layer opposite the grating and in close contact with it. Preferably receptor molecules are incorporated into the sensitive layer or they are attached onto the layer. A biosensor may contain further components, such as substrate.

The word 'biochip' used herein denotes a sensor chip or platform which comprises one or more biosensors i.e. multiplexed biosensor. The word 'microarray' generally used in the art means the same and the terms can be used interchangeably. Although the expressions 'biosensor' and 'biochip' used herein refer to biological applications, they should not be considered to limit the scope of the invention. As described in this application, the invention can also be adapted to other kinds of applications, such as detection of organic or inorganic molecules.

The term 'alkenyP as used herein includes straight-chained and branched alkenyl groups, such as vinyl and allyl groups. The term 'alkynyl' as used herein includes straight-chained and branched alkynyl groups, preferably acetylene. 'Aryl' means a mono-, bi-, or more cyclic aromatic carbocyclic group, substituted or non- substituted; examples of aryl are phenyl and naphthyl. More specifically, the alkyl, alkenyl or alkynyl may be linear or branched. Alkyl contains 1 to 18, preferably 1 to 14 and more preferably 1 to 12 carbon atoms. The alkyl is branched at the alpha or beta position with one or more, preferably two, CI to C6 alkyl groups, especially preferred are per-fluorinated alkyl, alkenyl or alkynyl groups. Some examples are non-fluorinated, partially fluorinated and per-fluorinated i-propyl, t-butyl, but-2-yl, 2-methylbut-2-yl, and l,2-dimethylbut-2-yl. Alkenyl contains 2 to 18, preferably 2 to 14 and more preferably 2 to 12 carbon atoms. The ethylenic group, i.e. two carbon atoms bonded with double bond, is preferably located at the position 2 or higher, related to the Si or M atom in the molecule. Branched is preferably branched at the alpha or beta position with one or more, preferably two, CI to C6 alkyl, alkenyl or alkynyl groups, particularly preferred are per-fluorinated alkyl, alkenyl or alkynyl groups.

Alkynyl contains 3 to 18, preferably 3 to 14 and more preferably 3 to 12 carbon atoms. The ethylinic group, i.e. two carbon atoms bonded with triple bond, group is preferably located at the position 2 or higher, related to the Si or M atom in the molecule. Branched alkynyl is preferably branched at the alpha or beta position with one or more, preferably two, CI to C6 alkyl, alkenyl or alkynyl groups, particularly preferred are per-fluorinated alkyl, alkenyl or alkynyl groups.

In the context of the disclosure the organic group substituent halogen may also be F, CI, Br or I atom and it is preferably F or CI. Generally, term 'halogen' herein means a fluorine, chlorine, bromine or iodine atom.

The term 'biological agent' used herein denotes a molecule of biological origin such as protein, polypeptide, polyclonal or monoclonal antibody, single chain antibody (scFv), a fragment of an antibody (Fab), antigen, small organic molecule, nucleid acid, steroid hormone, pharmacological molecule, lipid, cDNA probe, virus, viral capsule in part or in whole, bacteria, bacterial capsule or surface antigen in part or in whole, cell or biological sample. A biological sample can be for example blood, plasma, serum, gastrointestinal secretions, tissue homogenates, tumor homogenates, synovial fluid, feces, saliva sputum, cyst fluid, amniotic fluid, cerebrospinal fluid, peritoneal fluid, lung lavage fluid, semen, lymphatic fluid, tears, or prostatic fluid.

The expression ' the refractive index of the material being active against biological analyte' means that interactions with biological analytes, such as binding of the analyte to the material, affect the refractive index of the bioactive material. This can be utilized for example in sensor devices for measuring the presence or the amount of the analyte present.

2) MODES FOR CARRYING OUT THE INVENTION

The compositions are obtained by hydrolyzing a first silane having the general formula I

I

with a second component having the general formula II

X² _4-eMR¹ _fR² _gR³ _h II

Optionally together with a third compound having the general formula III

III

In the above formulas, the groups "X" (i.e. the reactive groups X , X and X ) are groups, which are cleaved off by the hydrolysis or condensation reaction. They are independently selected from hydroxyl, alkoxy, acyloxy, nitride, carboxyl, acetylacetonate and halogen. It is possible to use silanes, metals or metalloids wherein the X¹, X² and X³ are different or identical. By using different leaving groups, certain important advantages can be obtained, as will be explained below. In the preferred hydrolysable groups, X , X and X stand for halogen, preferably chlorine or bromine, or an alkoxy group, such as methoxy, ethoxy or propoxy. If X , X and X groups are condensable it is preferred that they are hydroxyl groups.

M and M' stand for metal or metalloid groups. Nanoparticles or oxidenanoparticels may also incorporated into the hybrid siloxane materials as as material matrix modifiers. Nanoparticles can be considered as particles smaller than 100 nm or preferably smaller than 20 nm. They can be in form of oxides such as silicon dioxide, aluminum oxide, and titanium dioxide or in form of semiconductors such GaAs, ZnS or PdS. According to invention, they may be incorporated into the monomeric siloxane system or they can formed in-situ during the synthesis of the hybrid siloxane material.

In order to provide an organically crosslinked material, there are reactive unsaturated or oxane groups present in at least one of the silane reactants. There can be such reactive groups present in two or more of the reactant groups. Thus, silanes of formulas I and III can contain unsaturated groups bonded to the silicon atom in addition to the aryl or alkyl groups, respectively, also present therein. The unsaturated groups contain double- or triple bonds (-C=C- or -C≡C-) or oxanes. Such groups are represented by alkenyl, alkynyl, epoxy groups. In particular, alkenyl groups are preferred because they provide high reactivity combined with reasonable stability. The "alkenyl" has preferably the following meanings in the definitions of substituents R¹ to R³, R⁵, R⁶, R⁸ and R⁹: linear or branched alkenyl group containing 2 to 18, preferably 2 to 14, and in particular 2 to 12 carbon atoms, the ethylenic double bond being located at the position 2 or higher, the branched alkenyl containing a CI to C6 alkyl, alkenyl or alkynyl group, which optionally is per-fluorinated or partially fluorinated, at alpha or beta positions of the hydrocarbon chain. Particularly preferred alkenyl groups are vinyl and allyl.

Substituents R² to R , R⁸ and R⁹ can stand for aryl, which means for a mono-, bi-, or multicyclic aromatic carbocyclic group, which optionally is substituted with Ci to C₆ alkyl groups or halogens. The aryl group is preferably phenyl, which optionally bears 1 to 5 substituents selected from halogen alkyl or alkenyl on the ring, or naphthyl, which optionally bear 1 to 11 substituents selected from halogen alkyl or alkenyl on the ring structure, the substituents being optionally fluorinated (including per-fluorinated or partially fluorinated)

Substituents R², R³, R⁵ to R⁹ stand for hydrogen, an alkyl group, including linear or branched alkyl groups containing 1 to 18, preferably 1 to 14, and in particular 1 to 12 carbon atoms, the branched alkyl containing a Ci to C₆ alkyl, alkenyl or alkynyl group, which optionally is per-fluorinated. In particular, the alkyl group is a lower alkyl containing 1 to 6 carbon atoms, which optionally bears 1 to 3 substituents selected from methyl and halogen. Methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl and t-butyl are particularly preferred.

The materials of present invention are produced by the steps of

a) hydrolyzing and/or condensing the above mentioned silanes and other precursors to produce a hybrid siloxane material; b) doping the material with biological agent; c) depositing the material in the form of a thin layer; and d) curing the thin layer to form a film or layer.

Or alternatively,

The present materials are produced by the steps of

e) hydrolyzing and/or condensing the above mentioned silanes and/or other precursors to produce a siloxane material; f) depositing the material in the form of a thin layer; curing the thin layer to form a porous film or layer.; and g) doping the material with biological agent.

Typically, the method comprises hydrolyzing the first, second and optionally third compounds in a liquid medium formed by a first solvent to form a hydrolyzed product comprising a hybrid siloxane material; depositing the hydrolyzed, condensed or partially condensed product on the substrate as a thin layer; and curing the thin layer to form a thin film having a thickness of 0.01 to 1000 μm. The various solvents, which can be used in the methods according to the invention, are water and various organic solvents. However, preferably the solvent is water when the present materials are produced through steps a) to d) as described above.

The hydrolyzed product comprising a siloxane material can be recovered and mixed with a second solvent to form a solution, which is applied on a substrate. The second solvent is removed to deposit the hydrolyzed product on the substrate as a thin layer, and then the thin layer to form a thin film having a thickness of 0.01 to 1000 μm.

The above hydrolysis steps of the first, second and third silicon compounds to form a hydrolyzed product and the step of curing the hydrolyzed product are all performed at a temperature of 0 to 500 °C, preferably less than 60 °C.

The hydrolysable group can be alkoxy, halogen, acyloxy, deuteroxyl, carboxyl, nitride or amine. The condensable groups can be for example, hyhydroxyl, alkoxy or halogen. The hybrid siloxanes are formed by hydrolyzing and condensating metal or metalloid compounds that contain one or more reacting group so that final material contains at least the Si-O-Si group.

A biological molecule can be doped into the material directly after hydrolysis and/or condensation i.e. before the material is further processed to form thin films or other structures. Alternatively, the biological molecule can be doped into the surface of the material after the material has been processed into thin film or other structure. In this case the immobilization of the biological molecule can be performed similarly as immobilization of theses molecules to glass. Such methods are well known in the prior art and include amine activation, aldehyde activation and nickel activation.

If a biological molecule is doped into the material directly after hydrolysis, the further processing of the material can be made at low temperatures (preferably lower than 60 °C) and in substantially neutral pH conditions. The processing in mild conditions is important to ensure the survival of the structure and function of the biomolecules. It is well known in the prior art that biological agents may lose their three-dimensional structure or it may be disrupted, and therefore lose their function, when subjected to high temperatures and/or very high or low pH conditions.

As explained above, the present silane precursors, which contain a hydrolysable group, also comprise organic groups, which are not hydrolyzed during the hydrolyzing steps. These groups are the above-mentioned R-groups of alkyl, aryl, alkene, alkyne, epoxy, acrylate, vinyl, cyano, amine, mercapto and partially or perfluorinated of the same. These non-hydrolyzed groups may, however, affect the reactivity of the previously described reacting groups. In addition, the reactivity of materials with different reacting (hydrolysis and/or condensation) groups varies as well. If hetero (two or more different precursors) precursor systems are use in the synthesis of siloxanes the homogeneity of the material may suffer due to the uneven reaction rates of the precursors.

For the film material that is made through steps e) to g) as described above:

In the place of mesitylene for the processing of the grating structures it is possible to use pure or mixture of following solvents: methyl-isobutyl ketone, 2- propanol, ethanol, methanol, 1-propanol, tetrahydrofuran, acetone, nitromethane, chlorobenzene, dibutyl ether, cyclohexanone, 1,1,2,2-tetrachloroethane, trichloroethanes, ethyl lactate, 1,2-propanediol monomethyl ether acetate, carbon tetrachloride, perfluoro toluene, perfluoro p-xylene, perfluoro iso-propanol, tetraethylene glycol, 2-octanol, dimethyl sulfoxide, 2-ethyl hexanol, 3-octanol, diethyleneglycol butyl ether, diethyleneglycol dibutyl ether, diethylene glycol dimethyl ether, 1,2,3,4-tetrahydronaphtalene or trimethylol propane triacrylate. The material solution can be made acidic or basic using following compounds: acetic acid, formic acid, propanoic acid, monofluoro acetic acid, trifluoro acetic acid, tiichloro acetic acid, dichloro acetic acid, monobromo acetic acid, triethyl amine, triethanol amine, pyridine, N-methyl pyrrolidone.

Photoinitiators that can be used are Irgacure 184, Irgacure 500, Irgacure 784, Irgacure 819, Irgacure 1300, Irgacure 1800, Darocure 1173 and Darocure 4265. The initiator can be highly fluorinated, such as l,4-bis(pentafluorobenzoyl)benzene or Rhodosil 2074. Thermal initiators which can be used are benzoyl peroxide, 2,2'- azobisisobutyronitrile, 1,1 '-Azobis(cyclohexanecarbo-nitrile), tert-butyl hydroperoxide, Dicumyl peroxide and Lauroyl peroxide, But they are not limited to these. Thermal initiators are optimized for their reactivity, thermal stability as well as chain transfer efficiencies. Typical radical initiators listed below work well with the system as well as other charge transfer catalysts that can be used as initiators. Material example 1

The material is synthesized as follows. 10 g of 3- glycidoxypropyltrimethoxysilane [M(GPTMS)=236.34 g/mol -> n(GPTMS)= 42 mmol] and 0.2966 g of silicon tetrachloride [M(SiCl₄)= 169.90 -> n(SiCl₄)= 1,75 mmol] are mixed and reacted in inert atmosphere. The mixture is refluxed at 80 °C for 2 hours time. The solution is cooled down. As a next step 60 g of A1₂0₃ (5-w-% in colloidal water solution) [M(Al₂O₃)=101.96, 0.05 x 60 g = 3g -> n(Al₂0₃)= 3 g/101.96 g/mol = 29 mmol] is added to the mixture. The solution is reacted 24 hours in room temperature. The material is finalized by distilling the volatile components e.g. methanol, water, free chlorine that are produced during the reaction (40 °C, 40 mbar, 1 h). After distillation 20 g of distilled water is added to the material. Material is then mixed using ultra sonic bath for 60 min is then stored in a fridge before final preparation with biological agent, purified commercially available antibodies (mouse anti-human leptin, part 840279 in Human Leptin DuoSet ELISA Development Kit DY398, purchased from R&D Systems Inc. Minneapolis, MN, USA) diluted in PBS (4.0 μg/ml). The final material is filtrated before spin coating using a 0.45 μm syringe- filter.

Material example 2

The material is synthesized as follows. 25 g of 3- glycidoxypropyltrimethoxysilane [M(GPTMS)=236.34 g/mol -> n(GPTMS)= 106 mmol] and 2.2245 g of silicon tetrachloride n(SiC14) [(13 mmol] are mixed and reacted in inert atmosphere. The mixture is refluxed at 80 °C for 1 hour. The solution is cooled down. As a next step 22.037 g of tetraethoxysilane [M(TEOS)= 208.33 g/ml → n(TEOS)= 106 mmol] is added to the mixture. The solution refluxed at 80 °C for 1 hour. After cooling the solution to room temperature 19.0 ml of 0.1 M HCl [n(H20)= 10 x n(GPTMS)] is added. Solution is stirred in room temperature for 24 hours. The solution is neutralized sodiumhydrocarbonate and filtered before final preparation with a biological agent purified commercially available antibodies (mouse anti-human leptin, part 840279 in Human Leptin DuoSet ELISA Development Kit DY398, purchased from R&D Systems Inc. Minneapolis, MN, USA) diluted in PBS (4.0 μg/ml). The final material is filtered before spin coating using a 0.45 μm syringe-filter. One embodiment of the invention provides a biosensor. A schematic diagram of an example of a biosensor structure is shown in Figure 1. The shown biosensor comprises a grating (103), a substrate layer (105) that supports the grating and a sensitive layer (102) in close contact with the grating but opposite side than the substrate. In addition to these, a biosensor can comprise a buffer layer (104) between the grating and the substrate, and/or a cover layer (101) in close contact with the sensitive layer but opposite side than the grating. More detailed diagram of the grating layer and the sensitive layer with used optical and geometrical parameters is shown in Figure 2. A substrate can comprise, for example, glass, silicon, epoxy, plastics or other suitable material. Optionally, a substrate and a grating comprise a single unit in which the and the substrate are formed of the same material. In addition to that the shape of the surface of the substrate is plane, it can also be concave. In that case the grating is called concave grating. Variety of techniques and materials can be used to fabricate the grating structures. Among these methods are: (1) wet and dry etch transfer technologies including patterning of the masking photoresist films, (2) replication technologies such as injection molding, hot embossing and UV molding including various techniques for mold fabrication, (3) non-lithographic technologies such as ink-jet printing and reel-to-reel printing, and (4) photolithographic patterning of a negative or positive lithography-tone photoimageable material with certain optical properties to a desired shape. The above described methods are illustrative only. Alternative fabrication methods can be used by those skilled in the art.

The grating can be manufactured from glass, plastic such as epoxy, acrylic, polystyrene, or sol-gel materials such tetraehylorthosilicate glass, hybrid organic- inorganic glass, silsesquioxane, organo silsesquioxanes, semiconductors such as silicon, doped silicon, GaAs, or metal. Some commercial materials that can be used to manufacture gratings include includes SU-8 (Microchemistry Inc.) and Cyclotene (Dow Chemical Inc.) Examples for fabrication of two-dimensional gratings are found in Wang. Opt. Soc. Am. 1990 8:1529-1544 and they are well known in the art. The gratings can be made out of epoxy or plastic by embossing which is a well- known manufacturing method.

A cross-sectional profile of the grating can comprise any periodically repeating shape, for example, binary (Figure 3A), sinusoidal (Figure 3B) or blazed (Figure 3C). Non-binary gratings, for example sinusoidal or blazed gratings can be produced using embossing or exposing photolithography sensitive material through gray scale masks. The profile depth (h₂) of the grating can vary from 100 nm to 100 μm, preferably from 500 nm 10 μm. The period (d) of the grating can vary from 1 μm to 100 μm. Both profile depth and period can be constant or they can vary over the grating area.

A grating can comprise of a repeating pattern of shapes including lines, squares, triangles, circles, ellipses, trapezoids, sinusoidal waves, ovals, rectangles and hexagons. For example a grating can comprise of a classical set of equal spaced lines. The repeating shape and the repeating period can be constant or they vary over the grating area. The above described grating structures are illustrative only. Alternative structures can be designed and used by those skilled in the art.

A scanning electron microscope picture of a grating that can be used in a biosensor is shown in Figure 14, where grating has been constructed on top of a glass substrate.

The grating can be coated with porous sensitive layer where biological receptors molecules can be attached. The sensitive layer can comprise of the described biocompatible material. The pore volume of the sensitive layer material can be from 20 to 65 percent by weight, preferably 30 to 55 percent by weight. The pore-size of the material can vary in different applications of the biosensor depending on the analyte to be measured. Generally the pore size is at the area of 30- 250 nm, preferably at the area of 40-200 nm, more preferably at the area of 50-150 nm. In one embodiment of the invention the grating is covered with porous hybrid aluminum oxide siloxane or hybrid organo modified tetraethoxysilane materials that have a water contact angle of 50° to 49° or 42° to 40° respectively.

Biological receptor molecules can be incorporated into the biocompatible material. Said receptors are specific for a desired analyte. Such receptors can be, for example, a protein, polypeptide, polyclonal or monoclonal antibody, single chain antibody (scFv), a fragment of an antibody (Fab), antigen, small organic molecule, nucleic acid, steroid hormone, pharmacological molecule, lipid, cDNA probe, virus, viral capsule in part or in whole, bacteria, bacterial capsule or surface antigen in part or in whole, cell or biological sample. A biological sample can be for example blood, plasma, serum, gastrointestinal secretions, tissue homogenates, tumor homogenates, synovial fluid, feces, saliva sputum, cyst fluid, amniotic fluid, cerebrospinal fluid, peritoneal fluid, lung lavage fluid, semen, lymphatic fluid, tears, or prostatic fluid.

The biological molecules can be mixed into the material solution when it is in liquid form. After the biological molecules have been inserted into the material the processing of the material will be performed in substantially neutral pH (e.g. pH 6.5 to pH 7.5) conditions and in low temperature (less than 50° C) to preserve functionality of the biological binding molecules.

Alternatively, the receptor molecules are bound to the porous sensitive layer after it has been applied on top of the grating. There are several methods to immobilize the receptors to a surface, well known in the prior art. The immobilization of the molecules can be carried out through covalent or non-covalent interactions with the host material. Some examples are shown in Figure 11. Amine activation, epoxy activation, carboxyl activation, hydroxyl activation, aldehyde activation, nickel activation, hydrazide coupling coupling of hydrophogic groups, the use of self-assembled monolayers, alkylsiloxane monolayers on hydroxylated surfaces, alkyl-thiol/dialkyldisulfide monolayers on noble metals, alkyl monolayer formation on oxide-free passivated silicon and avidin- or streptavidin-biotin coupling (Current Protocols in Protein Science, 2001; Khilko et al., 1995; Stein and Gerisch, 1996 ; O'Shannessay et al., 1992); Sigal et al, 1996; U.S. Pat. No. 5,405,766; PCT Publication WO 96/38762; U.S. Pat. No. 5,412,087; U.S. Pat. No. 5,688,642; U.S. Pat. No. 4,690,715; U.S. Pat. No. 5,620,850; Wagner et al., 1996; Linford et al. 1995; Wagner et al. 1997, U.S. Pat. No. 5,429,708) are examples of chemical binding methods that can be applied to the biosensor. Generally the immobilization of receptors can be performed similarly as immobilization of these molecules to glass.

Furthermore, different adaptations of the porous material can be used in the binding process. The porous material can be tailored to include number of different functional groups including but not limited to amine, aldehyde, carboxyl, hydroxyl, epoxy groups.

A scanning electron microscope picture of porous hybrid siloxane composite material that forms the sensitive layer on top of a grating structure is shown in Figure 15.

One embodiment of the invention provides a biochip. A biochip comprises one or more biosensors produced to the same substrate layer. The physical size of a biochip can vary e.g. from 1 mm x 1 mm to 50 cm x 50 cm, preferably from 5 mm x 5 mm to 100 mm x 100 mm. A biochip can have arbitrary shape. It can be for example square, rectangular, triangle, hexagonal or circle. The biosensors on a biochip can be different or identical in their size and structure. The biosensors can be miniaturized according to the rule that the smallest diameter of a grating is limited to be at least few times the period of the grating. So, a biosensor can be about 25 μm to about 1 cm in diameter, preferably from 100 μm to 3 mm. A biochip can comprise e.g. 1, 10, 100, 1000, 10000, 100000 or more than 1000000 biosensors, typically from 1 to 1000 biosensors. Such a biochip is called a microarray because one or more biosensors are typically laid out in a regular grid pattern. However, a microarray of the invention can comprise one or more biosensors laid out in any type of regular or irregular pattern. Figure 4 presents a schematic diagram of an example of a biochip, which comprises of 36 1 mm x 1 mm biosensors on a 10 mm x 10 mm substrate. Figure 5 presents a schematic diagram of an example of a biochip, where biosensors have been arranged in circular pattern.

A photograph of a biochip that comprises multiple biosensors is shown in Figure 16. The biochip is constructed on glass substrate. Each biosensor on a same biochip can be sensitive to different analyte by choosing the receptor that is present in the sensitive layer of the sensor, i.e. each biosensor on a same substrate can simultaneously measure different molecules. In one embodiment of the invention, the receptors can be molecules that are cleavable targets for one or more enzymes and a biosensor can be used to measure enzyme activities. If these enzymes are present in the analyte that is measured with the biosensors, the enzymes cleave their target molecules that are attached to the sensitive surface.

In one embodiment of the invention, one or more biosensors on a biochip can be used as a reference by not including or immobilizing specific receptors in the reference sensors sensitive layer, that are included in the sensitive layer of another otherwise identical biosensor.

In one embodiment of the invention, reference sensors can be used to detect unspecific binding in a sample.

In one embodiment of the invention, the measurements from reference channel , can be compared to measurements from another, otherwise identical biosensor.

Optionally, all biosensors on a biochip can comprise a single grating, i.e., a biochip can consist only one grating, which contains many distinct locations, each with a different receptor or with a different amount of a specific receptor. One example of a biochip of the invention is a circular biochip on which all biosensors are arranged in circles with certain radii. The circular biochip can be rotated which is especially good for rapid measurement of many biosensors. In one embodiment of the invention, a biosensor can be attached to a tip of an optical fiber and the optical fiber can act as a light source as shown in Figure 12). In one embodiment of the invention, multiple biosensors can be coupled to a single waveguide, which acts as a light source to all of the biosensors attached to the guide as shown in Figure 13).

In yet another embodiment of the invention, the waveguide can be constructed directly on top of the waveguide (Figure 13). A guide layer (1301) is applied on top of a substrate (1302), The guide layer is exposed to UV light through a waveguide mask (1303) and chemically developed. Thereafter, a planarization layer (1304) is applied on top of the waveguide. A grating is developed into the planarization layer, directly on top of the waveguide, by exposing the layer to UV light through a grating mask (1305). Sensitive layer is spinned on top of the grating structure to complete the biosensor. The sensitive material can include the biological receptors, or they can be applied after the device has been completely processed. An additional array layer (1306) can be constructed on top of the planarization layer to direct the liquid flow and handling. When a biological sample is analyzed, the biosensor is put in contact with the sample. For example, the sample can be applied onto the sensor or the sensor can be placed into the sample. The receptor molecules that are bound to the sensitive layer interact with the analytes that might be present in the sample.

In one embodiment of the invention, the analytes specifically bind to the receptors that are attached to the sensitive layer. Figure 6 shows an example of a situation where a sample has been applied on tope of the sensitive layer (601) and analytes (603) that are present in the sample have bound to antibodies (604) in the sensitive layer.

In one embodiment of the invention, specific DNA or RNA sequences or molecules (703) can be identified from a sample, when DNA probes with complementary nucleotide sequences (704) act as a receptor in the sensitive layer as shown in Figure 7.

When a molecule binds to the receptors present in the sensitive layer, the binding will have an effect on the optical properties of the said layer, and therefore the a biosensor can be used to detect wide variety of different biological, pharmaceutical, organic and inorganic molecules, given that a proper receptor is for the desired analyte can be used.

In one embodiment of the invention, the effect of the analyte binding can be amplified by further attaching more molecules to the complex that has been bound to the specific receptors in the sensitive layer. Figure 8 shows how the measurement of biotinylated analyte (804) can be amplified using streptavidin coated nanoparticle (803). The biotinylated analyte can be bound to the nanoparticle either before the sample has been applied to the biosensor, or thereafter.

In one embodiment of the invention, a biosensor that can be easily tailored, can be constructed by doping avidin or streptavidin (904) into the sensitive layer (901) as shown in Figure 9. Before binding the receptors into the sensitive layer of said biosensor, the receptors can be linked with biotin by methods that are well known in the art. The biotinylated receptors (903) can then be bound to the avidin/streptavidin that is bound to the sensitive layer of the biosensor. In another embodiment of the invention, enzymes that are present in a sample can react with their substrates and/or cleaving targets that are present in the sensitive layer as shown in Figure 10. The analytes (1003) in the sample interact with the receptors (1005) that are bound to the sensitive layer (1001). The result is the cleavage of the receptor (1005) in to two parts, of which only one is bound to the sensitive layer (1006). The analyte and the cleaved part of the receptor can be washed away from the sensitive layer and thereafter the change in the optical properties of the sensitive layer can be measured to determine the activity of the analyte towards the said receptor.

A sample, biological sample or other sample, can be put in contact directly or it can be pre-treated with variety of ways, well known to those skilled in the art. In one embodiment of the invention, a sample can be applied on to a biochip so that a single sample is in contact with several biosensors simultaneously as shown in Figure 38. The biosensors that become in contact with the sample can be each specific to their own analytes, or alternatively one or more may measure the same analyte. Furthermore, one ore more biosensors can be constracted so that it does not contain any receptors. Therefore these sensors act as a reference sensor for measurement of unspecific binding. In another embodiment of the invention, any number of samples can be applied to a biochip so that each sample comes in contact only one biosensors as shown in Figure 39. The biosensors can all measure the same or different analyte. Any variation with the number of biosensors that a sample comes in contact with is also possible. In one embodiment of the invention, a sample can be guided to a biosensor by using microfluidistic channels as is shown in Figure 40.

A biochip can also comprise of biosensors that all or some are specific towards a single analyte but have different receptors.

The sample can be washed away for example with water, aqueous solution, like buffer or with any suitable solvent.

When the properties of the sensitive layer change also the optical properties of the grating change. To measure these changes, a detection system is required. A detection system measures the intensities of certain diffracted light beams. These intensities, i.e. diffraction efficiencies, change as the optical properties of the grating change. The sensitivity of the detection system can be optimized by properly choosing the grating geometry, materials, measured diffraction orders and detection system configuration, and can be done by a person skilled in the art.

A detection system of the innovation can rely on the following principle. One or more light beams containing one or more wavelengths, one or more polarization, and possibly one or more different income angles are collimated or focused onto the same spot on the grating. Some of the intensities of the diffracted (reflected and/or transmitted) beams are detected by using one or more detectors. The changes of the refractive index of the sensitive layer of the biosensor can be calculated from the changes in the measured intensities. There are many possible variations about how the change in the refractive index is obtained from the intensities of the diffracted beams, and a skilled professional can easily find suitable solution for each application. For easier treating of the subject, let us divide the illumination light into

"channels" so that each channel contains only one linearly polarized monochromatic beam. So every incoming photon belongs to some channel with specified income angle, θ, polarization, p, and wavelength, λ. Every channel divides in the grating and is detected by one or more detectors. The detected intensity of the fc'th diffraction order beam of the channel (λ, p, θ) can be written in the following way

l(k, λ,p,θ,t) = P{λ, p, θ, t) ■ L_λ (λ, p, θ) ^■ L₂ (λ, p, θ, t) ^■ D(k, λ, p, θ, t) • L₃ (k, λ, p, θ, t) • J₄ (k, λ, p, θ) ■ S(k, λ, p, θ, t)

where λ = wavelength, θ = income angle, p = polarization, t = time, P - intensity of the source, Lj = the intensity loss factor from the source to the biochip, L₂ = the intensity loss factor from the biochip border to the grating layer, D = diffraction efficiency, L₃ = the intensity loss factor from the grating layer to the biochip border, L₄ = the intensity loss factor from the biochip border to the detector. S = the sensitivity of the detector which detects the Λr'th order beam. In addition to the channel parameters (λ,p,θ), these variables are functions of the order number k and the measurement time t. P, Lj and L₂ are the same for all orders because the orders have common path before the grating layer. Lj and L₄ are time-independent because they are properties of the detection device whereas L₂ and L₃ are properties of the biochip which can change with time. In principle the intensities of two or more diffraction orders are measured (the set of these diffraction orders is denoted with K) at the same time. Then the sum of a subset of the measured diffraction orders divided by the sum of another subset of the diffraction orders as

G(λ,p,θ,t) =

∑P(λ, p, θ, t) ■ L_x (λ,p, θ) ■ L₂ (λ, p, θ, t) ■ D(lc, λ, p, θ, t) ■ L₃ (k, λ, p, θ, t) ■ L, (k, λ, p, θ) ■ S(k, λ, p, θ, t)

IceKt

∑P(λ, p, θ, t) ■ L (λ, p, θ) ■ L₂ (λ, p, θ, t) ■ D(k, λ, p, θ, t) ■ ₃ (k, λ, p, θ, t) ■ Z,₄ (k, λ, p, θ) ■ S(k, λ, p, θ, t) keIC_z

where K_λ,K₂ e K , is calculated. This simplifies to the form

i.e. G is insensitive to the intensity noise of the source. In addition to that, it is insensitive also to the changes in L₂ which can happen for example when contamination or overly solution layer remains on the biochip between the source and the grating layer when the analyte is applied on it.

In most of the cases it can be supposed that L₃ is time independent. When measuring with the best sensitivity the following has to be considered: when measuring a transmission order and the light beam is coming through the grating layer to the substrate layer, it can be supposed that L₃ is really time independent. That is because it can be supposed that the loss factor through the substrate layer is time independent. When measuring the reflection orders one has to ensure that no overly solution layer remains on the biochip because that would cause time dependence to L₃. Most of the cases it can also be supposes that S is time independent. When measuring with the best sensitivity the effect of the time dependence of S can be minimized by careful device design and calibration. After all G simplifies to

∑ D(k, λ, p, θ, t) ■ L₃ (k, λ, p, θ) ■ L₄ (k, λ, p, θ) ■ S(k, λ, p, θ) ■ a(k, λ, p, θ) k<=K, G(λ,p,θ,t) =

∑ D{k, λ, p, θ, t) ■ L₃ (k, λ, p, θ) ■ L₄ (k, λ,p,θ)- S(k, λ,p,θ)- a(k,λ,p,θY k<=K,

where a is a known calibration function related to S. Now, the only changes of G as a function of time are caused by the changes in diffraction efficiency!).

It was supposed that the intensities of all the measured diffraction orders were measured at the same time. It is also possible to measure some or all of them in a series in a short time period during which the intensity of the source and the sensitivity of the detector are constant.

In order to measure the reflection orders the reflectance must be high enough. In that case the refractive index difference between the grating and sensitive material should preferably be high, more than 0.1. Another possibility is to use reflective substrate, for example silicon, with the grating and sensitive material which both have refractive index around 1.5. Still another possibility is to use metal substrate or metal grating. With abovementioned measurement principle one or more channels can be used to illuminate the biosensor. When using only one channel, i.e. only one linearly polarized monochromatic beam only one G - number will be monitored. In that case one has to had fully known and calibrated biosensor and detection system in order to be able to translate the changes in G to the changes in the refractive index of the sensitive material. This is practical in simple low cost applications where the sensitivity need not be optimized. However, for a device of high sensitivity it can be advantageous to use several channels by using several wavelengths for example. By using several channels it is possible to obtain more information about the biosensor than by using only one channel. Thus it is not necessary to know for example the exact shape of the grating beforehand if the refractive index difference between the grating layer and the sensitive layer is known. On the other hand, if the geometrical shape of the grating is known, it is not necessary to know the refractive index of the grating layer beforehand. Also by using several channels it is possible to see if the biosensor is broken before or during the measurement and so it is possible to know if the measurement result is right or not. Another important advantage of using several channels is that it is possible to average measurement results over the channels so that the measurement result will be better. These advantages are clear to a skilled professional and so the exact mathematical and physical treatment of the subject is not necessary in this context.

If power distribution between the polarization states is known, as usually is especially with bulbs and LEDs, it is possible to treat a monochromatic beam which includes both polarization states as one channel.

One embodiment of the detection principle is to use phase grating, for example a binary phase grating or a sinusoidal phase grating, the phase difference of which changes as a function of refractive index of the sensitive material. A phase grating also works as a weak amplitude grating the efficiency of which changes as a function of refractive index of the sensitive material.

In order to optimize the detection system it is important to solve the diffraction properties of the grating. The diffraction efficiencies of gratings can be solved analytically when the geometry of the grating is simple. In many cases however the analytical solution is too complex in comparison to relatively simple numerical modeling. Numerical modeling of diffraction gratings is possible for example by using GSOLVER (Grafting Solver Development Company, Allen, Texas, USA) software. GSOLVER utilizes a full 3-dimensional vector code using hybrid Rigorous Coupled Wave Analysis and Modal analysis for solving diffraction efficiencies of arbitrary grating structures for plane wave illumination. One embodiment of the detection principle is to measure the ratio of the intensities of the first transmission order and the zeroeth transmission order.

In addition to abovementioned preferred measurement principles a person skilled in the art can construct a wide variety of other mathematical functions which have the intensities of the diffracted light as parameters and which can be used to measure the change of the refractive index of the sensitive material. The diffractive element can have both phase and amplitude grating properties and they both can be taken in account. Detection systems working with abovementioned principles can be constructed in many various ways depending on the application. Detection systems can vary in sensitivity, complexity and cost according to what is needed. A very sensitive device could use several wavelengths, several income angle and measure several diffraction orders. The wavelength of the light can vary from visible to near infrared (VIS - NIR), preferable from 400 nm to 780 nm. The income angle can vary from 0 degrees to 90 degrees. On the other hand the most simple device could measure the zeroeth and the first order intensities by using only one beam with zero degrees income angle and one wavelength. The following detection system configurations are only examples as a person skilled in the art can easily construct many different variations which rely on the same measurement principles. A detection system can comprise (See Figure 37) sensor chip, a light source providing light, light detector(s) and optionally transmitting optics directing light from the source to the sensor chip, collecting optics which gathers light from the sensor chip to the detector(s), signal processing unit and possibly also a modulation unit. The transmitting optics are used to direct light from the source unit to the sensor chip. The transmission optics can be constracted in various ways depending on the application. Typically transmitting optics comprises a collimating or focusing unit, which shoots the beam through the biosensor. In many cases transmitting optics comprises also polarization filters and/or spectral filters. The collecting optics is used to collect light from the sensor chip to the detector(s). In some cases there is no need for the collecting optics. In other cases it comprises a focusing optics, which focuses the diffracted light to the one spot to the detector.

The collimating and focusing unit collimates or focuses the beam before it is directed to the biosensor. This is done for the following reasons: the beam diameter must be correct on the biosensor, the numerical aperture of the beam must be small enough so that different diffraction orders and channels do not mix together, and, the beam diameter on the detector must be small enough so that the whole spot fits in the detector area. Focusing can be done by using lenses, mirrors or diffractive optical elements.

In the following, the preferred embodiments of the detection system are described in more detail. Depending on the chosen configuration and measurement system, we might measure by using one or two polarizations. Almost every embodiments below, it is possible to choose whether or not to use polarizers and that is why polarizers are not drawn in the figures. Polarizers may be placed for example just after the collimating or focusing unit.

One embodiment of the detection system uses a monochromatic source. Monochromatic beam is collimated or focused to have small numerical aperture. The beam goes through the biosensor and divides into several transmission order beams by diffraction. By using one or more detectors two values are measured: the intensity of the zeroeth order (I₀) and the sum of the intensities of other orders (I_s). I_s can contain only the intensity of the +l:st order or I_s can contain the sum of the intensities of the +l :st and -l:st orders, or optionally also the intensities of several other orders. When the ratio I I is calculated, the change of the refractive index of the sensitive material is obtained when the original refractive index difference between the grating material and the sensitive material is known. It is supposed that the shape of the grating is well known too. Figure 18 illustrates one embodiment of the detection system. A beam from a wavelength stabilized and pulse modulated laser is directed through a collimating or focusing optics (1801,1802) to the biosensor (1803). The intensities of the zeroeth and the first transmission orders are detected by using two separate detectors (Det_1? Det₂) the both of which are connected into the same metal piece for temperature stabilization. For wavelength stabilization a part of the beam can be directed by using a beam splitter (1804) into a simple spectrometer which can comprise for example a blazed reflection grating (1805) with a CCD row detector.

Figure 19 presents one embodiment of the collecting optics where several transmission order beams from the biosensor (1901) are collected to the one detector (Deti) by using a focusing lens (1902).

Figure 20A presents another embodiment of the collecting optics where the zeroeth order beam is deflected to the separate detector (Det₂) by using a small mirror (2001).

Figure 20B shows another embodiment of the collecting optics, where several transmission order beams from the biosensor are collected to only one detector (Deti) by using a focusing lens. By using a spatial modulator (2002) like optical chopper, or LCD or DMD modulator, several diffraction orders can be measured in a short period of time. Using this solution the pulse modulation of the source is not needed. In another embodiment of the detection system a beam from a wavelength stabilized and pulse modulated laser is directed through a collimating or focusing optics to the biosensor. The diffraction orders are detected by using a CCD-row or CCD-matrix detector as shown in Figure 21. By this embodiment all wanted diffraction orders can be detected at the same time. In addition to that the CCD- detector controls the wavelength of the light so additional spectrometer is not needed.

Instead of the laser, LED's or bulbs with filters can be used as a light source in the abovementioned embodiments. Figure 22 illustrates one embodiment in which a light from a LED or bulb source (2201) is focused into a pinhole (2202) by using a mirror (2203) and lens (2204). Needed filters (2205) are placed after the collimating or focusing optics (2206). Figure 23 illustrates an embodiment in which a LED or bulb source (2301) is located inside an integrating sphere (2302), which contains a pinhole for light output (2303). When filters are used, the spectrometer is not needed for wavelength control. When using a bulb source a spatial modulator is needed for light modulation. That is because bulbs can not be pulsed as lasers or LEDs.

Figures 24, 25 and 26 illustrate embodiments where light is guided through optical fiber or optical waveguide from source to collimating or focusing optics. In Figure 24 the optical fiber (2401) collects light from the integrating sphere (2402) with a light source (2403) and guides it to the collimating or focusing optics (2404). In Figure 25 the light from a fiber pigtailed laser (2501) is divided by a fiber coupler (2502) to the collimating or focusing optics (2503) and to the spectrometer (2504). Figure 26 illustrates an embodiment where source (2601) is integrated into the substrate (2602), light couples from the source to the waveguide (2603), goes through Bragg grating filters (2604), is modulated by an electro-optical modulator (2605) and arrives to the collimating or focusing optics (2606).

Another embodiment of the detection system uses a source with a continuous spectral band. The spectral band can be from 10 nm to 1000 nm wide. The light is collimated or focused to have small numerical aperture. The beam goes through the biosensor and divides into several transmission order beams by diffraction. By using one or more detectors and the light modulator the ratio of the intensity of the zeroeth order and the sum of the intensities of some other orders are detected separately for each wavelength. When this ratio is known in the whole spectral band, the change in refractive index of the sensitive material can be calculated. The benefit for using several wavelengths is that the biosensor need not to be fully calibrated before measurement. For example if we know the original refractive index difference between and the grating material and the sensitive material, we can use the information obtained by using several wavelengths to calculate the refractive index change without previous information about the geometry of the grating. On the other hand, if we know the geometry of the grating, we can calculate the refractive index change without information about the original refractive index difference, for example. If the biosensor is well calibrated already we, by using wideband source, have possibility to make measurements with a better accuracy.

One embodiment of the detection system using a wide band source is shown in Figure 27. The light from a bulb (2701) is focused by a mirror (2702) and lens (2703) to a pinhole (2704). The light from the pinhole goes through a collimating or focusing (2705) unit after which it is filtered (2706) into the wanted spectral band. The beam is then modulated by a modulator, which can be for example a chopper or LCD (2707). The beam goes through the biosensor (2708) and divides into several diffraction order beams. Apart from the zeroeth order beam all other orders have spread into their spectra in horizontal direction. The spectrum of the zeroeth order is spread in vertical direction by using another grating (2709). These spectra are detected by using one large CCD-matrix or three or more smaller CCD-matrices or row detectors (2710).

As monochromatic sources, the wideband bulb sources can also be connected to an integrating sphere. Similarly, waveguides or fibers can be used for guiding light and fiber or waveguide components can be used for filtering, modulating or dividing light. Figure 28 shows an embodiment of the invention, where an integrating sphere (2801) is used with a wideband bulb source (2802). In this case the zeroeth order beam is spread into its spectram by using a prism-grating-prism (2803) component so that zeroeth order spectram can be detected by using the same row detector than for the +1 'st and -1 'st order spectra (2804).

One embodiment of the detection system uses wideband source with optical filters which filter out certain known bands from the spectrum of the source. These known spectral features can be used to calibrate the wavelength on the CCD-matrix or row detector.

One embodiment of the detection system uses wavelength tunable laser or a bulb with a scanning filter as a light source to get the same measurement result than with the wideband source. When using scanning light sources, the possible optical configurations are similar with the ones with monochromatic light sources. Figure 29. illustrates one embodiment of the source with a scanning filter. The light from a bulb (2901) is focused to the pinhole (2902) by using a mirror (2903) and a lens (2904). The light from the pinhole is guided through a collimating or focusing unit (2905) to the blazed reflection grating (2906) which spreads the beam to its spectram. The spectram is modulated with a spatial modulator (2907) like LCD and collimated again with a pair of lenses (2908).

Another embodiment of the detection system uses a source with several (two or more) narrow spectral bands. The advantage of this source is the same than with the case of the wideband source, i.e. we have possibility to better accuracy and the biosensor need not to be fully calibrated before measurement.

One embodiment of the detection system with a source with several narrow spectral peaks is presented in Figure 30 The source comprises of an integrating sphere (3001) with several LEDs (3002) and a pinhole (3003) for light output. LED's are electrically modulated so that only one wavelength band is active at each time moment. The light from the pinhole is collimated or focused (3004) and guided through the biosensor (3005). The beam divides into several diffraction orders which are detected by a CCD - matrix or a row detector (3006). At the same time, the wavelength stability of the spectral bands can be monitored by detecting the position of the diffraction orders at the detector. This wavelength information can be used to control the LED's temperature and current if needed. In addition to set of LEDs, the set of narrow wavelength bands can be produced by coupling light from lasers or filtered bulbs to the integrating sphere. One embodiment of the detection system, which is presented in Figure 31 uses white light source (3101) with Fabry-Perot interference filter (3102) to produce a series of narrow wavelength peaks.

Instead of CCD or row detectors, conventional silicon photodiodes can be used also when a series of narrow spectral bands are used as is illustrated in Figure 32. The optical configuration is the same that the ones with monochromatic light source apart from the light source. Light source, which comprises an integrating sphere (3201) with LEDs (3202) and a pinhole (3203), is modulated so that only one spectral peak is activated at each time moment. Another suitable light source for this kind of serial measurement is also a light bulb modulated by a filter wheel. One embodiment of the detection system uses several beams each of which illustrate the same spot on the biosensor but with different income angles. Figure 33 presents one possibility where collimated monochromatic beam coming from the source and focusing units, is divided vertically by using an additional grating (3301) into several beams with different propagation directions. These beams are focused into the one spot on the biosensor with vertical line groove pattern (3302) by using a lens (3303). Beams divide again but in horizontal direction. The following beam matrix can be detected for example by a CCD-matrix (3304). This solution can also be applied together with a beam including several wavelengths at the same time.

These abovementioned detection systems were examples of preferred configurations. A skilled professional can vary already mentioned optical configurations and construct new optical configurations, which rely on the abovementioned measurement principles. For example, it is well known that in most of the cases lenses can be replaced by mirrors or diffractive optical elements. Also bulk optical components can be replaced in many cases by fiber optical components or integrated optics.

EXAMPLE 3

Fabrication of biosensor

Biosensor fabrication begins with an untreated flat glass substrate (4" x 4"). The glass substrate is first cleaned by using acetone, isopropanol and methanol baths in ultrasonic cleaner. After this the substrate surface is treated in a plasma etcher for 5 min at 300W (0₂-gas). The glass substrate is coated with a negative lithography- tone photoimageable material by using a spin coater. After this the deposited film is exposed through a photomask in contact exposure-mode using a maskaligner (Karl- Sϋss, MA-6, UV-400 optics). The used photomask is specifically designed to produce the desired grating structure. In this case the photomask was designed to produce grating structures with period of 6 μm. A 5" x 5" photomask was used that had 25 similiar gratings with dimension of 0.5 mm x 0.5 mm. The exposure step is followed by a development step where the unexposed areas of the film dissolve into the used developer solvent. As a final step the produced grating structures are fully solidified by baking at elevated temperatures. In this example the gratings were baked at 200°C for 3 hours. The used negative lithography-tone photoimageable material can be choosed to have a low refractive index (e.g. 1.47 at 632.8 nm) or a high refractive index (e.g. 1.60 at 632.8 nm). The choice of the used grating material (with certain refractive index) has to be done based on the selected sensitive material layer (with certain refractive index) to be able to achieve the optimal sensitivity of the biosensor.

In this example the sensitive material layer was selected to be a hybrid aluminum oxide siloxane material with refractive index of 1.51 at 632.8 nm. The sensitive material layer is deposited on top of the gratings by using a spin coater. Finally the sensitive material layer is solidified by baking the sensor construct at elevated temperatures. In this example the samples were baked at 50°C for 15 hours.

EXAMPLE 4

Incorporation of Biological Receptors into the Sensitive Layer The biological receptor molecules that specifically bind to the desired analyte can be incorporated to the sensitive layer of the sensor device during the synthesis of the sensitive layer material.

Purified commercially available antibodies (mouse anti-human leptin, part 840279 in Human Leptin DuoSet ELISA Development Kit DY398, purchased from R&D Systems Inc. Minneapolis, MN, USA) were diluted in PBS into concentration of 4.0 μg/ml. 10 μl of the diluted antibody mixture (40 ng of anti-leptin antibodies) was mixed with 10 g of a soluble hybrid aluminum oxide siloxane material and mixed 10 minutes in ultrasonic bath for 10 minutes. The prepared hybrid material doped with anti-human leptin antibodies was deposited on top of the fabricated grating structures by using a spin coater as described in Example 3. After this the sensor construct was baked at 50°C for 15 hours.

EXAMPLE 5

Manufacturing of streptavidin doped biosensors

Streptavidin is a bacterial protein that has great affinity and specificity for biotin. Receptor proteins can be easily biotinylated by using methods well known in the art. Biosensors that have been doped with streptavidin can be easily modified to detect desired analytes by binding biotinylated receptors to the streptavidin that has been incorporated to the surface of the biosensor.

Purified commercially available streptavidin (AS-5000, purchased from R&D Systems Inc. Minneapolis, MN, USA) was diluted with H₂0 into concentration of 100 μg/ml. 100 μl of diluted streptavidin mixture (10 μg of streptavidin) was mixed with 10 g of a hybrid aluminum oxide siloxane material using an ultrasonic bath for 10 minutes. The prepared hybrid material doped with streptavidin was deposited on top of the fabricated grating structures by using a spin coater as described in Example 3. After this the sensor construct was baked at 50°C for 15 hours.

EXAMPLE 7

Immobilization of biological receptors into the sensor chip

Biological receptors that bind to the desired analyte can also be immobilized to the sensitive layer after the deposition and curing of the sensitive material layer on top of the gratings. Receptor molecules can be immobilized to a surface through variety of surface chemistries. Avidin/streptavidin - biotin coupling offers a precise method to attach biotinylated receptor molecules into biosensor which has been doped with streptavidin (Example 5). Purified commercially available biotinylated antibodies (mouse anti-human leptin, from Human Leptin DuoSet ELISA Development Kit DY398, purchased from R&D Systems Inc. Minneapolis, MN, USA) were diluted in PBS into concentration of 1.0 μg/ml. 10 μl volume of the diluted antibody mixture (10 ng of biotinylated anti-leptin antibodies) was applied to the surface of biosensor. After an immobilization period of 60 minutes in 37 °C the sensor was rinsed extensively with PBS and air-dried.

EXAMPLE 8

Optical modeling of biosensor

In this example biochips comprised of a glass substrate, a grating layer and a sensitive layer. The grating was a sinusoidal phase grating with a period of 6 μm. In this simple demonstration we wanted to design a detection system which uses 632.8 nm laser as a source, illuminates the biosensor with zero degrees income angle and uses both TE and TM polarized light. The measurement will comprise of the measurements of the zeroeth and the first order intensities before and after applying the analyte to the biosensor. After the measurements, the change in the refractive index of the sensitive layer could be calculated by using the information obtained in the simulations. These simulations can many times be replaced by measurements, but typically simulations can be done faster. Measurements have to be done instead of simulations when good accuracy is needed, at least simulations have to be verified by measurements partially. At first, the numerical modeling of the grating was used to optimize the modulation depth of the grating before manufacturing. The modeling was made by abovementioned GSOLVER software. The refractive index of the grating layer was 1.600 and 1.514 for the sensitive layer for source wavelength. Figure 34 shows the simulated diffraction efficiencies for zeroth (TO) and first (TI) transmission orders for TE and TM polarized light as a function of grating modulation depth. From this we can see that a good sensitivity can be obtained when the grating depth is more than 1.5 μm, for example 2.5 μm. On the other hand, greater depths than 3 μm are difficult to manufacture with a good quality when the period of the grating is 6 μm. From the figure we can also see that the diffraction is not significantly polarization dependent with zero degrees income angle.

If the manufacturing process preserves the shape of the grating constant and if we know accurately the refractive indexes it will be enough to measure the grating only after applying the analyte. In that case we can use simulation to approximate the change in the refractive index of the sensitive material from the measured diffraction efficiencies: Figure 35 shows the simulated diffraction efficiencies as a function of the change of the refractive index (nj) of the sensitive layer. In this simulation the grating modulation depth was 2.5 μm. Figure 36 shows the change of nj as a function of the ratio of the intensities of the first and zeroeth diffraction orders. This graph can be used to convert the measured intensities into refractive index change.

Preferably we will measure the ratio before and after the analyte has been applied to the biosensor. Supposing that we know the shape of the biosensor, from the first measurement we can calculate the exact height of the biosensor. This result can be used when calculating the refractive index change from the second measurement.

EXAMPLE 9

Detection of leptin using biosensor

An assay was performed to demonstrate the capability to detect biological molecules label free. The biosensor was fabricated by mixing rat monoclonal anti- leptin antibody (mouse anti-human leptin, part 840279 in Human Leptin DuoSet ELISA Development Kit DY398, purchased from R&D Systems Inc. Minneapolis, MN, USA) into a hybrid aluminum oxide siloxane material using an ultrasonic bath for 10 minutes. The prepared hybrid material doped with mouse anti-human leptin antibodies was deposited on top of the fabricated grating structures by using a spin coater as described in Example 3. After this the sensor constract was baked at 50°C for 15 hours.

In order to prevent non-specific binding, the biosensor surface was exposed to 1% solution of Bovine Serum Albumin (BSA) in PBS for 30 minutes and rinsed extensively. Following blocking, 10 μl drops of recombinant human leptin hormone (human leptin, in Human Leptin DuoSet ELISA Development Kit DY398, purchased from R&D Systems Inc. Minneapolis, MN, USA) in 1 μg/1 concentration was applied to the sensor surface. The droplets were allowed to incubate for 5 minutes before thorough washing of the unbound material with Dl water. The binding of the analyte was then measured using a laser beam and measuring the first/zeroeth-order ratios of transmitted light. A sensor constructs with no specific receptors incorporated into the sensitive layer were used as controls. The results of the binding assay are shown in Figure 17.

Alternative process methods in all previously mentioned manufacturing processes may be accomplished by using so called reel-to-reel (also called roll-to- roll) processing, wherein the view of achieving of the objectives stated above the method for manufacturing optical elements is mainly characterized in that the method comprises the steps of supplying a printing cylinder with printing elements for forming optical structures, applying optical material on the printing cylinder and creating the optical structures on the substrate material web or substrate material sheets. According to the method optical elements are produced in a printing system in which the optical element is transferred from the printing cylinder to a suitable substrate material. In an extreme case the whole substrate material can be covered with optical material. The substrate material is paper or plastic or other passive or active optical/electrical material, such as a semiconductor material. The substrate material is in a form of a web or separate sheets of suitable size. Optical material is a material system that can be handled and delivered in the liquid format to its final location, e.g. substrate, in which it forms to a stable or metastable phase, i.e. a solid or metasolid form. After taking the stable or metastable phase the material presents optical properties, which can be for example transparency or selective transparency, reflectivity, diffraction, light emission, polarization selectivity, modulation or phase modulation. The optical material can be e.g. an organic polymer that is dissolved in an appropriate solvent such as organic solvent or water. The material can also be a suspension of solid particles in a liquid carrier. In both cases the material forms stable or metastable form when the solvent or the carrier is removed. However, the invention is not restricted to these materials.

The manufacturing of the optical elements according to the method comprises the primary printing step in which the optical element is formed on the substrate surface using the primary printing method. The primary printing system is preferably a gravure printing system, a gravure offset printing system, a flexographic printing system, an offset lithographic system, electrophotographic printing system, or a combination of these.

Gravure printing includes direct gravure printing, in which the printable pattern is transferred from the printing cylinder to the printing surface, gravure offset printing in which the printable pattern is transferred from the printing cylinder to a second cylinder and from it to the printing surface, and intaglio printing. In intaglio printing process viscous inks are used which allow the printing patterns of larger uniform areas. After the primary printing phase the printed optical element is optionally treated with an additional printing method(s). In the additional printing phase devices for digital printing, hot stamping, silk, screen printing and/or photolithographic printing may be applied.

The method makes it possible to produce high quality optical elements at a cost which is a remarkably lower than whoa using conventional methods. This is preferably achieved by manufacturing a printing cylinder provided with surface structures to form optical elements on a substrate material. The printed optical component is formed by using a liquid form optical material that is suitable for printing systems, and is, if needed, cured with suitable method. The printed optical elements can further be laminated, covered or printed with additional optical layers. The curing method can be such as thermal curing or UV curing.

Advantages of using the gravure printing method are deep enough, structures achievable in gravure printing, high quality of the transfer of the printing pattern, high throughput, and low price compared to the conventional methods of producing optical elements. The gravure printing method can also be easily integrated to other process parts such as lamination, coating or embossing.

In additional step the printed optical element is further provided with additional layers to form the desired optical and biochemical coatings. Suitable methods for additional treatment of the optical elements are hot stamping, photolithographic printing method and silk screen printing. In hot stamping printing method, ink coated on a film transfers by heat and pressure to a web. The raised parts of the profile contact the film, and the resulting heat flow causes liquidification of the ink. In silk screen printing method the printing plate is replaced by a stencil having different porosity in the printing and nonprinting areas. Ink is pressed through the stencil to the paper or other substrate positioned below the stencil. According to the process method the additional step for manufacturing optical elements may also include using a stamping unit in which an area consisting of an optical layer is printed on the web and then an optical pattern is stamped on this area. In the method for producing optical elements a printing cylinder is prepared containing printing elements of the form of optical elements. The optical elements are created on a substrate surface ranning as a web through the printing system. According to the method the printing elements in the printing cylinder are preferably of the form of lines or other three-dimensional structures instead of point structures of the prior art printing cylinders. According to the process method the additional step for manufacturing may include coating of biochemically sensitive coating on a previously prepared optical components. The biochemically sensitive coatings are created on a substrate surface running as a web through the printing system.

Claims

CLAIMS:

1. Biocompatible material characterized in that it comprises a composition obtained by hydrolyzing;

1) a monomeric silicon compound having at least one hydrolysable or condensable group attached to the silicon atom of the compound with;

2) another monomeric compound having at least one chemically reactive group attached to the metal or metalloid atom of the compound to form a hybrid siloxane composite material.

2. Biocompatible material according to claim 1, characterized in that the composition contains a monomeric silicon compound having at least one organic crosslinking group attached to the silicon atom to from a hybrid siloxane composite optical biocompatible material.

3. Biocompatible material according to claim 1, characterized in that the composition contains a monomeric silicon compound having at least one organic crosslinking group attached to the silicon atom and aluminum oxide nanoparticle compounds to from a hybrid siloxane composite optical biocompatible material.

3. Biocompatible material according to claim 1, characterized in that the composition is optically active against biological analyte.

4. Biocompatible material according to claim 1, characterized in that the refractive index of the material is active against biological analyte.

5. Biocompatible material according to claim 1, characterized in that the composition comprises a biological agent containing hybrid organosiloxane.

6. Biocompatible material according to claim 1, characterized in that the composition comprises a crosslinked hybrid organosiloxane.

7. Biocompatible material according to claim 1, characterized in that at least one the hydrolysable groups is chlorine.

8. Biocompatible material according to claim 1, characterised in that the composition comprises a hybrid organosiloxane obtained by hydrolyzing or condensing a first silicon compound having the general formula A

wherein X¹ represents a hydrolysable or condensable group;

R¹ is an epoxy, alkenyl or alkynyl group, which optionally bears one or more substituents;

R and R are independently selected from hydrogen, substituted or non-substituted alkyl groups, substituted or non- substituted epoxy, alkenyl and alkynyl groups, and substituted or non-substituted aryl groups; a is an integer 1, 2 or 3; b is an integer ; 0, 1, 2 or 3; c is an integer 0, 1, 2 or 3; d is an integer 0, 1, 2 or 3; and b + c + d > l, but < 4

with a second compound having the general formula B

X _4-eMR _fR _gR B

wherein X represents a hydrolysable or condensable group;

R⁴ is an aryl group, which optionally bears one or more substituents;

R and R are independently selected from hydrogen, substituted or non-substituted alkyl groups, substituted or non- substituted alkenyl, alkynyl groups, substituted or non- substituted aryl groups, or substituted or non-substituted acrylate; e is an integer 0, 1, 2 , 3 or 4; f is an integer 0, 1, 2 , 3 or 4; g is an integer 0, 1, 2 , 3 or 4; h is an integer 0, 1, 2 , 3 or 4; and f+ g + h < 4

9. Biocompatible material according to claim 8, characterized in that the composition is obtained by hydrolyzing the first and the second compounds with a third compound having the general formula C

wherein X³ represents a hydrolyzable or condensable group;

R is hydrogen, amine, cyano or mercapto group, which optionally bears one or more substituents; R and R are independently selected from hydrogen, substituted or non-substituted alkyl groups, substituted or non-substituted alkenyl or alkynyl groups, substituted or non-substituted aryl groups, substituted or non-substituted oxane, substituted or non- substituted aery late or hydroxyl group; i is an integer 0, 1, 2 or 3; j is an integer 0, 1, 2, 3 or 4; k is an integer 0, 1, 2, 3 or 4; 1 is an integer 0, 1, 2, 3 or 4; and j + k + l < 4.

10. Biocompatible material according to claim 8, characterized in that the composition is obtained by hydrolyzing or condensing the first and the second compounds with nanoparticles.

11. Biocompatible material according to claim 9, characterized in that the nanoparticle is silicon dioxide, aluminum oxide or titanium dioxide.

12. Biocompatible material according to claim 9, characterized in that the nanoparticle is GaAs, PdS or ZnS.

13. Biocompatible material according to claim 9, characterized in that the R⁷ act as a chemical linger of biological agent into the matrix.

14. Biocompatible material according to claim 3 or 4, characterized in that the

1 "" hydro ollyyssaabbllee ggrroouuppss XX¹ ,, XX² and X³ are independently selected from hydroxyl, alkoxy, acyloxy and halogen.

15. Biocompatible material according to claim 5, characterized in that the hydrolysable groups X , X and X are different.

16. Biocompatible material according to claim 5, characterized in that the

1 9 " hydrolysable groups X , X and X are identical.

17. Biocompatible material according to claim 7, characterized in that each of the hydrolysable groups X¹, X² and X³ stands for halogen, preferably chlorine or bromine.

18. Biocompatible material according to claim 1, characterized in that the refractive index of the material at He-Ne is between 1.29 to 2.4, preferably between 1.4 to 1.6.

19. The use of biocompatible material according to any preceding claim, characterized in that it is used in a sensor device.

20. The use according to claim 19, characterized in that the sensor device is biosensor or biochip.

21. The use of biocompatible material according to any of the claims 1-18, characterized in that the material is used when constructing a microfluidic channel.

22. The use of biocompatible material according to any of the claims 1-18, characterized in that the material is printed to a surface.

23. The use of biocompatible material according to any of the claims 1-18, characterized in that the material is used in bioactive filter.

24. The use of biocompatible material according to claim 23, characterized in that the filter contains an agent having biological or chemical activity.

25. The use of biocompatible material according to claim 24, characterized in that the biological or chemical activity if antimicrobial activity.

26. Biocompatible material according to claim 1, characterized in that the composition contains at a monomeric silicon compound having at least one organic crosslinking group which is epoxy.

27. Biocompatible material according to claim 1, characterized in that the composition contains at a monomeric silicon compound having at least one organic crosslinking group which is vinyl.

28. Biocompatible material according to claim 1, characterized in that the composition contains at a monomeric silicon compound having at least one organic crosslinking group which is acrylic.

29. Biocompatible material characterized in that it comprises a composition obtained by hydrolyzing and/or condensing;

1) a monomeric silicon compound having at least one hydrolysable or condensable group attached to the silicon atom of the compound with;

2) another monomeric compound having at least one chemically reactive group attached to the metal or metalloid atom of the compound to form a biochemically compatible optical material.

30. Biocompatible material characterized in that it comprises a composition obtained by hydrolyzing and/or condensing; 1) a monomeric silicon compound having at least one hydrolysable or condensable group attached to the silicon atom of the compound with; 2) another compound having particle size less than lOOnm.