TWI406940B - Matrix array nanobiosensor - Google Patents

Description

Matrix column nano biosensor

The present invention generally relates to biosensors, particularly biosensors configured in a matrix array.

Simultaneous monitoring of multiple analytes (liquids and gases) has diverse applications in a variety of fields, such as metabolic monitoring, chemistry, biowafer detection, gas detection, and more. Most current sensors have many limitations when monitoring more than one analyte due to cross-sensitivity and other compound interference problems. This limitation is detrimental to the continuous detection of multiple analytes. Some multiplex analyte monitoring systems do not have sufficient miniaturization for in vivo applications or other sensitive applications. There is no joint sensor array that can simultaneously monitor gases and liquids.

There have been several research reports on the development of biosensor arrays using different methods. A common biosensor format for enzyme-based biosensor arrays to monitor fruit quality has been reported (see Biosensors & Bioelectronics (2003), 18(12), 1429-1437). These sensors use pectin as a fixed substrate, but the fixing method is "drop and dry mechanism", which does not produce good sensitivity.

A two-enzyme biosensor for characterization of wastewater combines tyrosinase and horseradish peroxidase (HRP) or cholinesterase-modified electrodes on the same array (see Analytical and Bioanalytical Chemistry, Vol. 376, Issue 7, 2003, p. 1098). It discusses the performance of a double enzyme biosensor array in batch mode and flow-injection system.

A multi-functional biosensing wafer based on hydrogen peroxide generated by electrochemiluminescence (ECL) detection enzymes has been reported (see Marquette, Christophe A.; Degiuli, Agnes; Blum, Loic J., Biosensors & Bioelectronics (2003), 19(5), 433-439). Among them, six different oxidases specific for choline, glucose, glutamate, lactate, lysine and urate are non-covalently immobilized on the array sensor, but the detection range is limited. In hydrogen peroxide.

It has been reported that a pin printed biosensor arrays (PPBSA) in which needle-printed protein-coated xerogels are used (see Cho, Eun Jeong; Tao, Zunyu; Tehan, Elizabeth) C.; Bright, Frank V., Analytical Chemistry (2002), 74(24), 6177-6184). The sensor detects glucose and oxygen simultaneously. Its total array-to-array response reproducibility is around 12%, which limits the long-term stability of the sensor.

For a more complete understanding of the present invention and its advantages, reference will now be made to the accompanying drawings.

In the following description, numerous specific details are set forth, such as specific memory array configurations and the like, to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without the specific details. In other instances, well-known circuits are shown in block diagram form in order to avoid obscuring the invention in unnecessary detail. In most cases, details regarding timing and the like have been omitted since such details are not required to fully understand the present invention and are within the skill of the ordinary skill in the art.

The elements shown in the drawings are not necessarily to scale, and the like elements are in the

The system of the invention shown in Figures 1-2 is a matrix column nanobiosensor for monitoring nine analytes comprising a carbon nanotube, a conductive polymer, a biological enzyme, a nanoparticle and Other nanoscale materials are built into the sensor element (working electrode) in a three-electrode electrochemical system. The sensor elements are sufficiently miniaturized to operate with very small amounts of analyte and can be used in sensitive applications. The substrate is prepared using a low cost lithography fabrication process, and the sensor has a miniaturized electronic configuration that can couple nine individual electrodes for efficient detection.

The sensor can be used, for example, in the following areas: metabolic monitoring (glucose, lactose, fructose, urea, uric acid, phenol, alcohols, ascorbic acid, hydrogen peroxide, phospholipids, and other metabolites), chemical warfare detection (salin ( Sarin), tabun (ie dimethyl cyanoacrylate), soman, hydrogen cyanide, cyanogen chloride, mustard, chlorine and other chemical warfare agents, biological warfare agents (ricin, Peptides and others), potential biochemical agents (PCB's such as organophosphates, DMMP, marathon, ethion, balason, paraozon and others), DNA hybridization, gas monitoring (toxic gases) Such as CO, SO ₂ , NO, NO ₂ , NH ₃ , H ₂ S and others), as well as metals (mercury, arsenic and others). The matrix nano biosensor can be used to detect gas and liquid multiplex analytes.

Lithography fabrication of matrix nano biosensors:

Referring to Figure 1, 1 micron cerium oxide is deposited on a germanium wafer by chemical vapor deposition (CVD) (step a). A shadow mask having a desired pattern is placed on the substrate (step b), and 100 angstroms are deposited by electron beam deposition (electron beam deposition) Chromium and then 500 angstroms of gold (step c). Remove the shadow mask (step d). 0.3 μm of tantalum nitride was deposited by a CVD method (step e). The substrate is coated with a photoresist (step f). The substrate is patterned by photolithography using a mask (step g) (step h). The exposed tantalum nitride (Si ₃ N ₄ ) pattern is removed via reactive ion etching (RIE) (step i). The photoresist was removed (step j), and an Ag/AgCl paste (available from Gwent Electronic Materials Ltd, UK) was screen printed onto the reference electrode pattern (step k). The Ag/AgCl can also be obtained by electrodeposition of a layer of silver at -200 mV by a potentiostatic method followed by electrodeposition of a chloride layer at +200 mV. The electrical connector is then soldered to each electrode (step 1).

Sensor manufacturing:

The step of developing the matrix nano biosensor substrate by photolithography in FIG. 1(h) is shown in step (1) of FIG. 2, wherein there are nine individual working electrodes 201 and one reference electrode. 203 (web-printed Ag/AgCl paste), and a counter electrode 202 (gold).

In step 2 (Fig. 2), a carbon nanotube (CNT) 204 is dispensed (sprayed or screen printed) onto the nine working electrodes 201 using a suitable mask (not shown).

By mixing 50% by weight of carbon nanotubes with 43% by weight of organic (or inorganic) vehicle and 7% by weight of glass frit in mortar and pestle for 30 minutes, followed by milling in a three-roll mill 20 The carbon nanotube paste electrode (0.5 square centimeter) was prepared by dispersing the agglomerates in the mixture in minutes. The inorganic vehicle was purchased from Cotronics Corp., Brooklyn, NY, USA. The substrate was then baked in an oven at 100 ° C for 10 minutes and cooled at room temperature. Electrodes can also be prepared using different weight percentages of carbon nanotubes. The prepared carbon nanotube paste electrode can be heated (hot baked) to remove the organic vehicle and activated by tape.

By dissolving a known amount of carbon nanotubes (eg, 0.1 g) in 20 ml of isopropanol, followed by ultrasonic treatment for 5 minutes, and spraying the resulting solution onto the substrate (矽 substrate, vacuum evaporation) A carbon nanotube spray electrode (0.5 square centimeter) was prepared with 20 angstroms of chromium and 500 angstroms of gold. The spray electrode was then baked in an oven at 100 ° C for 10 minutes and cooled at room temperature.

The carbon nanotubes which can be used in the present invention can also be prepared by chemical vapor deposition including a catalyst such as nickel, copper, cobalt, iron and a carbon source such as acetylene, ethylene, methane and other hydrocarbons. Or prepared by other methods known to those skilled in the art.

In step 3 (Fig. 2), the oxidation of aniline (0.1M) and 1 mg/ml of different biological enzymes in a solution containing 0.2 MH ₂ SO ₄ in a pH 7.0 buffer are used. Enzyme, the preparation of the enzyme solution will change according to the enzyme activity at a specific pH), continue to electrochemically polymerize the carbon nanotube electrode in situ and immobilize the enzyme (applicable to all the aforementioned electrodes) . In the electropolymerization and enzyme immobilization, a potential window of -1 volt to 1 volt and a scan rate of 50 millivolts per second were used for 10 cycles. The different enzymes 205 for the nine sensor elements 201 can be selected according to the specific analytes in Table 1, but the enzyme systems that can be used for the matrix nanobiosensor are not limited to those in Table 1 below.

The electropolymerization and enzyme immobilization of polypyrrole and these enzymes were carried out under the same electrochemical conditions by oxidation of pyrrole (0.1 M) in a solution containing 0.1 M NaClO ₄ in a pH 7.0 buffer. The electrode was then rinsed with water and air dried. Other conductive polymers can also be used in these matrix nano biosensors. In addition, other biological entities such as antibodies, nucleic acids, aptamers, and the like can be immobilized on the nanotubes using similar methods.

In step 4 (FIG. 2), the sensor element is placed in a suitable electronics housing and coupled to an external electronic configuration via electrode 206. The sensor element is also filled with an electrolyte required for a particular electrochemical reaction based on the analyte (liquid or gaseous) to be detected. The nine working electrodes 201, the opposing electrode 202, and the reference electrode 203 are coupled to a drive electronics configuration (described below) that is a constant potential circuit required for any three-electrode electrochemical system.

Electronic drive combination:

Referring to Figure 3, the proposed electronic configuration coupled to the aforementioned array is comprised of a multiplexer driver. It can be operated in either pulsed or continuous scan mode, using a low power microprocessor and is programmable. The processor drive signal is output to a digital analog converter (D/A converter) that drives all of the sensors and a digital analog converter that reads the output of the sensor. For each sensor there is a controlled impedance op amp that is multiplexed to handle the periodic reading of each sensor in turn. The software in the processor calculates the current background current and performs an algorithm to detect peaks above the expected background value. After correcting the chemically induced peak shift, the peak is compared to the pattern of known analytes. The results are presented in qualitative and quantitative output pathways. In the final system, the qualitative pathway will be selective, and if the analyte is present, it will be displayed as an LED display or other suitable device. Since the peak current of the only redox potential of the analyte is a significant improvement over the simple resistive base sensor array, false positive/negative values can be effectively eliminated. The components of the electronic combination can be the following:

(a) Electrometer

The electrometer circuit 301 measures the voltage difference between the reference electrode 203 and the working electrode 201. Its output has two main functions: it is a feedback signal in a constant potential circuit, and it is a signal that is measured whenever a cell voltage is required. An ideal electrometer has zero input current and unlimited input impedance. The current flowing through the reference electrode 203 changes its potential. But in reality, all modern electrometers have input currents close enough to zero, so this effect is usually negligible. Two important characteristics of an electrometer are its bandwidth and its input capacitance. The electrometer bandwidth characterizes the measurable AC frequency when the electrometer 301 is driven by a low impedance. The electrometer bandwidth is higher than the bandwidth of other electronic components in the constant potential circuit. The electrometer input capacitance forms a RC filter with the reference electrode resistance. If the time constant of this filter is too large, it will limit the effective bandwidth of the electrometer and cause system instability. Smaller input capacitance means more stable operation and greater tolerance to high impedance reference electrodes.

(b) Current and voltage converter

The current-voltage (I/E) converter 302 in this diagram measures the cell current. It forces the cell current through the current measuring resistor Rm. The voltage drop across Rm is a measure of the cell current. Several different Rm resistors can be transferred to the I/E circuit 302 under computer control. This allows measurement of widely varying currents, each of which can be measured using a suitable resistor. An "I/E autoranging" algorithm is usually used to select the appropriate resistor value. The bandwidth of the I/E converter is mainly determined by its sensitivity. Small current measurements require large Rm values. The stray (unwanted) capacitance in the I/E converter 302 forms an RC filter with Rm, limiting the I/E bandwidth.

(c) Control amplifier

Control amplifier 303 is a servo amplifier. It compares the measured cell voltage to the desired voltage and drives the current into the cell to force the voltage to be the same. It should be noted that the measured voltage is input to the negative input of the control amplifier 303. A positive perturbation in the measured voltage produces a negative control amplifier output. This negative output counteracts the initial perturbation. This combination of controls is a conventional negative feedback. Under normal conditions, the cell voltage is controlled to be the same as the signal source voltage.

(d) signal

Signal circuit 304 is a computer controlled voltage source. It is typically the output of a digital analog (D/A) converter (see the DAC in Figure 15), which converts the computer-generated digital to voltage. Proper selection of the digital sequence allows the computer to generate a constant voltage, a voltage ramp, or even a sine wave of the signal circuit output. When a D/A converter is used to generate a waveform such as a sine wave or ramp, the waveform is a digital approximation of the same analog waveform. It contains a small voltage step. The size of these steps is controlled by the resolution of the D/A converter and the rate at which new digital updates are made.

Sensing agency:

One of the sensing mechanisms is electrochemical based as previously described. The stereometric system is achieved by cyclic voltammetry which characterizes the unique current oxidation potential. The stereometric measurement is performed by a chronoamperometric measurement at a fixed characteristic potential as determined by cyclic voltammetry. The liquid phase sensor requires only a small amount of analyte (micro-mole range), while the gas phase sensor is provided with a hydrophobic film and a liquid or solid electrolyte. The solid electrolyte can be any anion exchange membrane (such as nafion), nanoporous ceria (such as xerogel, hydrogel).

Cyclic voltammetry (CV) techniques can be used to immobilize enzymes onto the nanotubes (in this voltage system step change, typically between -1 volt and +1 volt and sweeping a loop). Nine different enzymes (E) can be immobilized on the sensor elements using CV to form a sensor array. The nine different enzymes are selected to have a unique response to nine different analytes (A) [eg glucose oxidase (E) versus glucose (A)]. When the analyte is in contact with the sensor, the matrix is initiated by an electronic structure (the background electrochemical procedure in the electronic configuration is CV), and the CV has a reaction from the enzyme (E) to the analyte (A) for each analyte. The only redox peak. The soft body corrects the concentration level of the analyte based on the resulting redox peak of each analyte.

The chronoamperometry is operated by fixing the constant voltage, and the current versus time is plotted. The characteristic voltage of each analyte obtained from the previous execution of CV was fixed. The advantage of this technology is that it can be measured on the fly and is faster than the CV scan method.

The response of the matrix nanobiosensor to hydrogen peroxide is shown in equation (1) below. As an example, ten enzyme systems are exemplified. From this it can be seen that hydrogen peroxide is a by-product of the enzyme reaction in equations (2) to (6).

2H ₂ O ₂ → 2H ₂ O+O ₂ +2e ^- ---(1)

The abbreviations used are: α-KG=α-oxoglutarate L-Glu=L-glutaminate β-NADH=β-nicotamine adenine dinucleotide, reduced form β-NAD=β - nicotinamide adenine dinucleotide, oxidized form---(8)

The response of the nine individual components of the matrix nanobiosensor to hydrogen peroxide is shown in Figure 4. Although the original carbon nanotubes oxidize hydrogen peroxide, the presence of enzymes and conductive polymers is essential for the enzyme biosensing applications of the present invention. As can be seen from the figure, there is a small change in peak response and current oxidation voltage, but the anodization potential is still much lower than that described in the literature. It has previously been reported that glucose sensors have been developed by adding palladium, copper, ruthenium or osmium and glucose oxidase to carbon paste electrodes (Sylvia A. Miscoria, Gustavo D. Barrera, Gustavo A. Rivas, "Analytical Performace of a Glucose Biosensor Prepared by Immobilization of Glucose Oxidase and Different Metals into a Carbon Paste Electrode", Electroanalysis, 14, No. 14 2002, pp. 981-987) and incorporation of ruthenium particles and polyphenol oxidase into the carbon paste matrix A phenol sensor (MDRubianea, GARivas, Electroanalysis , 12, 1159) was obtained. However, these methods do not include a conductive polymer matrix and involve mechanical mixing of the enzyme into the carbon paste matrix.

The enzyme system exemplified in equations (7) to (10) does not release hydrogen peroxide due to biochemical reactions, but can be monitored by monitoring other products, namely dehydroascorbic acid (ascorbate oxidase, equation 7), glutamic acid Salt (L-glutamic acid dehydrogenase, Equation 8), CO ₂ (formate dehydrogenase, Equation 9), benzoquinone (polyphenol oxidase, Equation 10), and analytes were detected. The present invention is not limited to the ten enzymes exemplified in the reaction systems or those shown in Table 1, but can be applied to any enzyme system having redox activity. As an example, a cyclic voltammogram of the in situ polymerization of aniline (0.1 M in 0.2 MH ₂ SO ₄ ) and ascorbic acid (equation (7)) is fixed to the carbon nanotube electrode. Figure 5. A response plot of peak response current (0.6 volts) due to oxidation of ascorbic acid to dehydroascorbic acid is shown in Figure 6. The selectivity of the sensor is illustrated in Figure 7, where the oxidation peaks of hydrogen peroxide are clearly distinguishable. This removes the interference of ascorbic acid and provides a higher selectivity.

Similar results were obtained for other enzyme systems. Although the different enzymes were immobilized on nine individual components, the matrix nanobiosensor was not disturbed by the continuous sensor elements.

Matrix nano biosensor stability:

The matrix nanobiosensor array is stable in multiple measurements (more than one hundred measurements) and the sensor lifetime is a function of enzyme activity. The conductive polymer matrix in the nanobiosensor provides good stability to the nanotube matrix. The specific enzyme stability based on the biochemical activity of the enzyme is shown in Table 2. The stability of the enzyme extends the life of the sensor.

Matrix nano biosensors are used to detect toxic gases: carbon monoxide (CO) sensors: the working electrode is made up of nanostructured platinum material, ie platinum nanoparticles or carbon nanotubes coated with platinum nanoparticles. . The main reason for using platinum as a working electrode is its known catalytic oxidation of carbon monoxide. Coating the platinum nanoparticles on the carbon nanotubes increases the surface catalytic activity of the working electrode on CO, resulting in higher sensitivity. The opposite electrode is composed of a metal such as platinum, gold, or the like and a reference electrode such as Ag/AgCl. The electrolyte is a strongly acidic electrolyte (such as 5M H ₂ SO ₄ ), and the sensor is enclosed in a hydrophilic semipermeable membrane.

The electrochemical reaction involved in detecting carbon monoxide using the sensor is: reaction on the sensing electrode: CO + H ₂ O → CO ₂ + 2H ⁺ + 2e ^- reaction on the opposite electrode: 1/2O ₂ + 2H ⁺ + 2e ^- → H ₂ O total reaction: CO + 1/2 O ₂ → CO ₂

The cyclic voltammogram of CO oxidation occurring on the platinum electrode using this sensor is shown in Figure 8, where the lower curve does not show characteristic peaks because there is no CO present. When CO is exposed to the sensor, there is a characteristic oxidation peak at about 0.85 volts. The proposed method using the carbon nanotube-platinum nanoparticle composite will have higher sensitivity and lower oxidation potential than those observed with a hydrogen peroxide sensor. Figure 9 illustrates the timing current response of the sensor to CO exposure. Because the platinum-catalyzed CO oxidation has a characteristic of a 0.85 volt oxidation peak, the sensor has a fast response time and provides reliable measurements.

The above system illustrates the fabrication of a nine-element matrix for use in developing nano biosensors. Previously designed electronic configurations included individual drives of individual electronic components and reference and opposing electrodes. While this design is a good development for single-element biosensors, extending this design to the development of n x n sensor components is somewhat difficult. The prior design also included a planar structure in which the reference, opposing, and working electrodes were all in a tantalum wafer oriented in the X-Y plane. If the biosensor substrate is linear, the nanobiosensor can be extended to detect hundreds of analytes. Therefore, an optimized design and electronic drive are needed to expand the diversity of nano biosensors.

The following systems provide selective design of nano biosensors. The disclosure herein is: 1) A linear design method for a three-electrode system (working, opposing, reference electrodes).

2) The reference electrode is specifically placed in the vicinity of the working electrode in a single element and matrix column form.

3) A design in which one half of the opposite electrode is permeable to the hydrophobic film, and the opposite electrode is placed in the electrolyte separate from the film at a position close to the reference and working electrodes. This is extremely important for the development of electrochemical gas sensors.

4) Develop miniaturized electronic structures that can drive linear and matrix column elements. The sensor electronics are capable of performing cyclic voltammetry and chronoamperometry in the sensor without the need for a standard laboratory constant potential circuit.

5) Design an active matrix for nano biosensor applications (similar to the active matrix of liquid crystal display devices) that can contribute to the development of n x n sensor elements in small areas. The present invention first reveals the development of active matrix systems for power chemistry (three-electrode) systems. The electronic construction developed for the active matrix uses a shift register and can drive all of the sensor elements in the active matrix.

An electrochemical sensor with a three-electrode system (working, opposing, and reference electrodes) operates in an electrolyte coupled to an external potentiometric circuit (see Figure 3). A variety of designs have been reported for electrochemical-based sensors, but there are few array-based sensors dedicated to the development of detection of multiple analytes. The challenges of multi-sensor arrays are cross-interference from other compounds, stability of sensor elements, and the like. Biosensors using capture reagents have been reported. Apparatus and methods for detecting analytes using biosensors with capture agents are found in World Patent WO 0138873 (2001), but are limited to detecting a single analyte. Although different nanoscale materials, such as nanotubes, nanowires, and nanoparticles, have been used as matrix or binders, there is still a lack of a uniform approach to the development of matrix nano-organisms capable of multiple analyte detection. Sensor. Compared to technologies based on optical, dielectric, capacitive, and electrical resistance, electrochemical biosensing technology has excellent diversity in accurately detecting liquid and gas analytes. In the disclosed invention, the specific interaction of the analyte with the biological agent can be monitored electrochemically over time.

It is disclosed in U.S. Patent No. 6,656,712 that the protein is subsequently passed to a carbon nanotube by incubation (without agitation). The biomacromolecule in solution is then at the appropriate temperature and pH conditions, then to the near end of the carbon nanotube. The present invention utilizes a method comprising electropolymerization with a conductive polymer matrix for the subsequent attachment of macromolecules, enzymes, proteins, antibodies, aptamers, nucleic acids, antigens, DNA, ribosomes. An array of such sensors can be completed in a matter of minutes and provides a stable architecture for electrochemical/biochemical reactions. The present invention also provides a highly efficient method for simultaneously detecting gas and liquid analytes using a hydrophobic semipermeable membrane. The electrolyte can be wet (liquid phase) or dry (nifepene film, nanostructured cerium oxide, hydrogel and others) for detection of chemical, biological warfare agents, gas detection, metabolic monitoring and others. application.

Linear Array Nano Biosensor:

The design of a linear nanobiosensor of one system of the present invention is shown in Figures 10, 11A and 11B. 11A and 11B are a plan view and a partial cross-sectional view, respectively, of one of the electrode combinations illustrated in Fig. 10. As previously mentioned, the sensor elements are comprised of a carbon nanotube 1100, a conductive polymer, and a biological enzyme 1101. The sensing element is a working electrode 1104 that is carried on the germanium substrate 1110; other substrates such as plastic (polymerizable), glass, ceramic, ITO, kapton, and printed circuit board can also be used. An insulating layer for the bare substrate may be a metal nitride, a metal oxide, a polymer, or the like. The reference electrode 1103 can be made of Ag/AgCl (silver, silver chloride), SCE (standard calomel electrode), SHE (standard hydrogen electrode) or other standard reference electrode. The opposite electrode 1102 can be a conductive layer such as gold, silver, copper, titanium, platinum, chromium, aluminum, or the like. In a linear configuration, an insulating carrier (not shown) may be provided to separate the reference electrode 1103, the working electrode 1104, and the opposing electrode 1102 because the three electrodes must be separated from each other during the electrochemical procedure. The present invention provides an efficient way to detect liquid and gas analytes. The gas sensor can use a closed hydrophobic semipermeable membrane (not shown) which can also be selectively permeable to distinguish between different gases (electron and electron acceptors). The film can be on the opposing/working electrode or separate from the system. The purpose of the membrane is to allow the gas to enter the working electrode in a single direction for electrochemical reaction. It will be appreciated that the purpose of the reference electrode 1103 in the three-electrode system is to maintain a stable potential around the working electrode 1104.

In the designs provided in Figures 10, 11A and 11B, the opposing electrode 1102 is placed over a linear system. It is generally preferred to position the opposing electrode 1102 away from the working electrode 1104 and at least ten times the area of the working electrode area.

Active Matrix Lenami Biosensor:

Active matrix circuits have previously been used in liquid crystal display devices (Azuma, Seiichiro, " Fabrication of Thin-Film Transistor for Active-Matrix Liquid-Crystal Display, " Patent: JP 2003100639, 2003; Hebiguchi, Hiroyuki, " Active Matrix Type LCD In Which a Pixel Electrodes Width Along a Scanning Line is Three Times lts Data Line Side Width, "US Patent No. 6 , 249 , 326, 2001). The effectiveness of the matrix nanobiosensor can be improved by using a row-column addressable array that can develop nxn matrices that are manufactured cost-effectively and miniaturized. Figure 12 shows a top view of an exemplary 3 x 3 matrix column comprising nine working electrodes (W _{1 1} to W _{3 3} ) (as described above with respect to Figure 11), wherein each working electrode configuration is comprised of a column and Driven by a row driver (see Figure 14). For example, the working electrode W _{1 1} is driven by column 1 (R1) and row 1 (C1). Sensor elements (ie, the working electrode configuration) also includes an active device (AC) for the column - row addressing, which should be "open" R1 and C1 to start working electrode W _{1 1.} The active matrix column design can drive multiple working electrodes simultaneously, which is not possible with linear array design. For example, a voltage of -1 volt to 1 volt at a scan rate of 50 millivolts per second in a cyclic voltammetry procedure would take 80 seconds for an electrode. The design of Figure 2, in which the working electrodes are arranged in a linear fashion, takes 12 minutes to read the responses of the nine analytes. This is a big disadvantage in the sensing of multiple analytes. Figure 14 illustrates an active matrix configuration in which the simultaneous driving of the working electrode significantly reduces the detection time (for example, a voltage of -1 volt to 1 volt at a sweep rate of 50 mV/sec. 80 seconds). This design provides a lot of room for the multiplexer of the sensor and the miniaturization of hundreds of sensors with micro-assembly technology. An active component (AC) is formed on the circuit, which can include different configurations as shown in FIG. The active circuit can include two diodes (Fig. 13a) connected to a diode of a capacitor and a resistor (Fig. 13b), or a transistor (Fig. 13c). The invention is not limited to the active matrix components described above, but can be extended to any "active" electronic circuit that can perform column-to-row addressing operations on a matrix column nano biosensor. For any of the working electrode configurations (W _{x y} ) shown in Figure 13, the active matrix should be connected to columns (R _x ) and rows (C _y ) as shown in Figure 12.

These active working electrode assemblies should be combined with reference and opposing electrodes (see Figure 11) to supply a chemical reaction. Electrochemical techniques include, but are not limited to, cyclic voltammetry, chronoamperometry, differential pulse voltammetry, linear sweep voltammetry, stripping voltammetry, AC voltammetry, AC impedance, and the like. The sensor can also be used to detect analytes by amperometry, potentiometry, conductance assay, voltammetry, or a combination thereof. Figure 14 shows a cross-sectional view of an n x n array matrix nano biosensor with column driver 1401 and row driver 1402. The structure comprises an n x n array of working electrodes 1104, each of which comprises a specific carbon nanotube 1100, a conductive polymer, an enzyme combination 1101 as previously described. The present invention is not limited to the above-described mixing of the above components, but carbon (all forms), precious metals (gold, platinum, etc.) and proteins, antibodies, nucleic acids (DNA, RNA), peptides, suitable bodies, and suitable bodies can be used. An aptazyme, and a combination of different conductive polymers.

Drive electronics construction:

The drive electronics configuration of the matrix Lenami biosensor is shown in FIG. The active matrix Lenami biosensor includes a shift register 1401 coupled to the nxn array working electrode 1104, the shift register being coupled to a data input, a clock, and an enable. The working electrode array is coupled to a current voltage (I/E) converter 1402, the reference electrode is coupled to an electrometer circuit 1403, and the electrometer circuit is coupled to a control amplifier 1404 coupled to the opposing electrode 1102. The different components of the electronic circuitry of the linear array sensor are similar to those shown in FIG. The reference electrode 1103 shown in the drawing is arranged to cross the working electrode 1104, but different configurations may be used without being limited to those shown in the present invention. The commonly used voltage sweep is about -1 volt to +1 volt, the scan rate is 50 millivolts, and the step is 1 millivolt, but other voltage windows, scan rates, and step sizes can also be used for cyclic voltammetry. measuring. The multi-pass output from the nxn array is coupled to a display device (not shown) or an alarm (not shown) to show the presence of the analyte. The design shown in Fig. 15 can be used to simultaneously drive nxn sensor elements by constructing miniaturized circuitry (electrometer, I/E converter, control amplifier) for each sensor element. The column and row drivers shown in Figure 14 can address any X-Y component in the sensor matrix. Each active component 1405 (AC) can be controlled by column-row addressing by opening 1406.

Although the present invention and its advantages are described in detail, it is understood that various changes, substitutions and changes can be made without departing from the spirit and scope of the invention as defined by the appended claims.

In Figures 2 and 3:

201. . . Working electrode

202. . . Relative electrode

203. . . Reference electrode

205. . . Enzyme

301. . . Electrometer

302. . . I/E converter

303. . . Control amplifier

304. . . signal

R _m . . . Resistor

In Figures 10 to 15:

1100. . . Carbon nanotube

1101. . . Enzyme

1102. . . Relative electrode

1103. . . Reference electrode

1104. . . Working electrode

1110. . . Substrate

1401. . . Column driver (Figure 14), shift register (Figure 15)

1402. . . Row driver (Figure 14), I/E converter (Figure 15)

1403. . . Electrometer

1404. . . Control amplifier

1405. . . Active component

1406. . . open up

AC. . . Active component

W _{1 1} ~ W _{3 3} . . . Working electrode

R ₁ ~R ₄ . . . Columns 1 to 4

C ₁ ~ C ₄ . . . Lines 1 to 4

W _{x y} . . . Working electrode

R _x . . . Column x

C _y . . . Line y

Figure 1 shows a system of the invention.

Figure 2 shows a system of the invention.

Figure 3 shows the electronic circuitry for information input and output in the system of the present invention.

Figure 4 shows the responses from nine sensors.

Figure 5 shows the response of the system of the invention.

Figure 6 shows the response of a matrix biosensor to ascorbic acid.

Figure 7 shows a response diagram of an exemplary system of the present invention.

8 through 9 show operational diagrams of a sensor configured in accordance with the present invention.

Figure 10 shows another system of the invention.

Figures 11A and 11B show further details of another system of the present invention.

Figure 12 shows a matrix column system of the present invention.

Figure 13 shows an active circuit for use in an array of the present invention.

Figure 14 shows a matrix column configuration in accordance with the system of the present invention.

Figure 15 shows another system of the invention.

Claims (6)

A method for detecting multiple analytes using an array of nanobiosensors, wherein a plurality of nanobiosensors in the array have fixed by conductive polymer by electrochemical polymerization and biological entity immobilization a unique biological entity on a carbon nanotube, wherein the first of the plurality of nanobiosensors has a first biological entity immobilized on a carbon nanotube, and wherein the plurality The second of the nano biosensor has a second biological entity immobilized on the carbon nanotube, the first biological entity being unique relative to the second biological entity, and each of the nano organisms The sensor includes a working electrode having a biological entity immobilized on a carbon nanotube, a reference electrode, and an opposite electrode. The method of claim 1, wherein the electrodes are connected to circuitry to scan each of the nanobiosensors. A device for detecting multiple analytes comprising an array of nanobiosensors, each of the sensors comprising a biological entity immobilized on a carbon nanotube using a conductive polymer, wherein the array Most of the nano biosensors have a unique biological entity, wherein the first of the plurality of nano biosensors has a first biological entity immobilized on a carbon nanotube, and the majority The second of the nano biosensor has a second biological entity immobilized on the carbon nanotube, the first biological entity being unique relative to the second biological entity, and each of the nano organisms The sensor includes a fixed carbon nanotube The working electrode of the biological entity, the reference electrode, and the opposite electrode. The device of claim 3, wherein the electrodes are connected to the circuitry to scan each of the nanobiosensors. The device of claim 3, wherein the reference electrode system is in close proximity to the individual working electrodes and is configured in an active matrix configuration. The apparatus of claim 3, wherein the plurality of working electrodes configured in the active matrix are simultaneously driven to detect multiple analytes.