CN113138212A

CN113138212A - Low-cost high-throughput electrochemical and photoelectrochemical sensor and preparation method thereof

Info

Publication number: CN113138212A
Application number: CN202110357418.8A
Authority: CN
Inventors: 胡成国
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 2021-04-01
Filing date: 2021-04-01
Publication date: 2021-07-20
Anticipated expiration: 2041-04-01
Also published as: CN113138212B

Abstract

The invention provides a preparation method of a low-cost high-throughput electrochemical and photoelectrochemical sensor, which comprises the following steps: step 1): constructing a large-area, high-uniformity and high-conductivity thin film electrode and/or a photoelectric thin film by using the dispersion liquid of the conductive material and/or the photoelectric material; step 2): constructing a micropore array; step 3): assembling the micropore array film electrodes and/or the photoelectric film obtained in the step 2) into a two-electrode micropore array sensor by adopting an adhesive or hot pressing mode; step 4): dripping a test solution on the surface of the addressable two-electrode micropore array sensor obtained in the step 3) to form a liquid drop detection cell array, and exciting the liquid drop detection cell array by addressing based on an electric or optical excitation signal to obtain the low-cost high-flux electrochemical and photoelectrochemical sensor. The method is simple and controllable, the production equipment is low in cost, automatic mass production is easy to realize, the detection device is integrated, the sample consumption is low, and the detection flux can be flexibly adjusted.

Description

Low-cost high-throughput electrochemical and photoelectrochemical sensor and preparation method thereof

Technical Field

The invention relates to the field of electronic device preparation, in particular to a low-cost high-throughput electrochemical and photoelectrochemical sensor and a preparation method thereof.

Background

In vitro diagnostic techniques have important value for the discovery and monitoring of major diseases and for the life health of people. Taking the new coronary pneumonia epidemic situation as an example, the early discovery and isolation become the advantages of our country in overcoming the spread of the epidemic situation. Currently, optical analysis methods are mostly adopted for in vitro diagnosis, including high-sensitivity and high-flux automatic fluorescence, chemiluminescence and other instrument analysis methods and colloidal gold test strips and other portable detection devices. However, the large-scale optical instrument analysis method is expensive in equipment and difficult to realize rapid on-site analysis, and the colloidal gold test strip is convenient to use and rapid in detection speed, but relatively poor in sensitivity. Therefore, the development of novel low-cost, highly sensitive, high-throughput, portable biochemical assays is of great interest in the field of in vitro diagnostics.

The electrochemical sensor has the characteristics of simple and portable detection equipment, low detection cost, high sensitivity and the like, and has a better application prospect in the field of portable field analysis. For example, the mainstream technology for blood glucose detection is portable electrochemical blood glucose analyzer based on enzyme catalysis reaction. However, there is a large gap in the conventional electrochemical sensing principle in terms of detecting flux compared to the optical method, limited by its sensing principle. At present, the electrochemical sensing method generally adopts a multi-signal mark or multi-electrode array and other modes to realize high-flux detection, the detection flux of the former is limited, the equipment and the material consumption of the latter are high, the multi-electrode preparation process is complex, and the commercial application is difficult to realize. Therefore, the development of high-throughput detection systems like the optical 96/256 well plate with low-cost single-channel electrochemical detection equipment remains a great challenge.

A single working electrode with a large area is partitioned, and then addressing detection of electric or light excitation signals can be carried out, so that high-throughput electrochemistry and photoelectrochemistry biochemical analysis can be realized by adopting single-channel electrochemical detection equipment. Based on this principle, we have previously established a series of addressed photoelectrochemical biosensors, including: (1) based on the principles of DNA hybridization and affinity reaction, a gold membrane electrode with a large area and a fullerene-based photoelectric biological probe are used to establish a high-sensitivity photoelectrochemical sensor (Analytical Chemistry 2015,87(18),9368-9375) for the related DNA of the multi-target virus; (2) based on steric effect unmarked sensing principle, large-area electro-deposition of Bi is used₂S₃A photoelectric film, which establishes a rapid detection photoelectrochemical sensor (Biosensors and Bioelectronics 2017,91,53-59) of the multi-target tumor marker; (3) based on the cutting effect of thrombin on immobilized biotin-labeled polypeptide in a micropore array on the surface of a large-area gold electrode, the fullerene photoelectric biological probe is labeled by avidin,a high-throughput detection and screening method for thrombin and thrombin inhibitors (Analytical Chemistry 2018,90(15),9366-9373) is established. The method proves the feasibility of single electrode addressing photoelectrochemical biosensing from the aspects of principles and devices, but has a plurality of defects in the aspect of practical application. Firstly, the working electrode and the reference electrode of the sensor are structurally separated, all the working electrode partitions and the reference electrode and the counter electrode must be placed in the same solution when photoelectric testing is carried out, and different samples cannot be monitored simultaneously or dynamically by using a liquid drop array; secondly, the gold membrane electrode with a larger area prepared by electroless deposition is used as a working electrode in the work (1) and (3), the preparation period of the gold membrane electrode is long, the influence factors are more, and the disease marker can be detected only by adopting a sandwich immunity or DNA hybridization structure with multi-step incubation; finally, work (2) although preparing Bi with higher uniformity₂S₃The photoelectric film has more influencing factors and lower production efficiency in the aspect of preparing a large-area functional film by adopting an electrodeposition method.

Therefore, the development of the addressing electrochemical or photoelectrochemical sensing device and the preparation method thereof, which have controllable preparation process, high production efficiency, more applicable sensing materials and strong universality, has important value for promoting the industrial application thereof.

Disclosure of Invention

The invention aims to solve at least one technical problem in the prior art to a certain extent, and provides a preparation method of a low-cost high-throughput electrochemical and photoelectrochemical sensor, which adopts the schemes of filtration and the like to construct a large-area, high-uniformity and high-conductivity thin film electrode and a photoelectric thin film, uses the cutting technology of laser engraving and the like to construct a micropore array on the thin film electrode and the photoelectric thin film, and assembles the micropore array thin film electrode and the photoelectric thin film into an addressable double-electrode micropore array sensor with a stacked structure (the composition and the basic structure schematic diagram of a single-channel addressable electrochemical and photoelectrochemical sensor are shown in figure 1). Based on addressing excitation of an electric or optical excitation signal to a liquid drop detection pool on the micropore array sensor, the single-channel electrochemical detection equipment and the automatic addressing device with low cost are adopted, the detection efficiency of the optical 96/256 pore plate can be realized, the preparation process is simple and controllable, the production equipment cost is low, the automatic mass production is easy to realize, the detection device is integrated, the sample consumption is low, and the detection flux can be flexibly adjusted.

Meanwhile, the sensor integrates the working electrode and the reference electrode together to form a micropore array, and a micro-volume test solution is introduced to the micropore array to form a mutually isolated liquid drop array detection cell. In the addressing detection process, all the subarea liquid drop array detection cells of the sensor comprise working electrodes and reference electrodes, so that the potential stability of each subarea working electrode can be greatly improved, the noise interference can be reduced, and meanwhile, the structure can be compatible with signal output modes such as electrochemistry, photoelectrochemistry and electrochemiluminescence, so that the automatic addressing detection of different samples or the continuous dynamic monitoring of different micro-reaction systems can be realized. Therefore, the sensor can be used as a universal electrochemical biosensing platform to develop a portable, low-cost, high-sensitivity and high-flux POCT/drug screening/pesticide residue detection system.

In a first aspect of the present invention, the present invention provides a method for preparing a low-cost high-throughput electrochemical and photoelectrochemical sensor, comprising the steps of:

step 1): depositing the dispersion liquid of the conductive material and/or the photoelectric material on the surface of a substrate or a microporous or nanoporous filter membrane through a filtration scheme or an ink-jet printing scheme to construct a large-area, high-uniformity and high-conductivity thin-film electrode and/or a photoelectric thin film;

step 2): constructing a micropore array on the thin film electrode and/or the photoelectric thin film obtained in the step 1) by adopting technologies such as laser or mechanical cutting;

step 3): assembling the micropore array film electrodes and/or the photoelectric film obtained in the step 2) into an integrated addressable two-electrode micropore array sensor with a stacked structure by adopting an adhesive or hot pressing mode, and performing insulation packaging on the addressable two-electrode micropore array sensor by adopting a UV printing, screen printing or adhesive tape template mode;

step 4): dripping a test solution on the surface of the addressable two-electrode micropore array sensor obtained in the step 3) to form a droplet detection cell array, and realizing high-flux electrochemical and photoelectrochemical detection by adopting single-channel electrochemical detection equipment and automatic or manual addressing detection equipment based on addressing excitation of an electric or optical excitation signal to the droplet detection cell array, thereby obtaining the low-cost high-flux electrochemical and photoelectrochemical sensor.

In one or more embodiments of the present invention, in the step 1), the conductive material is selected from a composite conductive material composed of one or more of gold, silver, platinum, carbon nanotubes, nanoparticles of graphene, nanowires, nanotubes, and nanosheets.

In one or more embodiments of the present invention, in the step 1), the photoelectric material is selected from one of fullerene, bismuth sulfide, silver sulfide, bismuth vanadate, or a composite photoelectric material composed of one or more of nano-gold, carbon nanotube and graphene.

In one or more embodiments of the present invention, in the step 1), the filtering scheme is to deposit the dispersion liquid of the conductive material on the surface of the microporous or nanoporous filter membrane by a filtering method, and then dry the membrane electrode to form the large-area, highly uniform, and highly conductive membrane electrode.

In one or more embodiments of the present invention, in the step 1), the inkjet printing scheme is to deposit a dispersion of a conductive material or a precursor thereof on the surface of the substrate by inkjet printing, and then dry the substrate to form a large-area, highly uniform, and highly conductive thin film electrode.

In one or more embodiments of the present invention, in the step 1), the filtering scheme is to deposit the conductive material and the photoelectric material on the surface of the microporous or nanoporous filter membrane in a mixed or layered filtering manner, and form the large-area, highly uniform, and highly conductive photoelectric thin film after drying;

in one or more embodiments of the present invention, in the step 1), the inkjet printing scheme is to inkjet print the mixed solution of the conductive material and the photoelectric material onto the substrate, or to inkjet print a large-area continuous conductive film first, then to inkjet print a continuous or patterned photoelectric material layer, and to form a large-area, highly uniform, and highly conductive photoelectric film or pattern after drying;

in one or more embodiments of the present invention, in the step 1), the material of the micro-or nano-porous filter membrane is selected from cellulose, polytetrafluoroethylene, polyvinylidene fluoride, nylon, polyether, polysulfone, alumina or derivatives thereof.

In a second aspect of the present invention, the present invention provides a low-cost high-throughput electrochemical sensor, which includes a plurality of micropore array detection cells arranged in an array, each micropore array detection cell includes a disk-shaped working electrode at a bottom layer, a ring disk-shaped reference electrode at a middle layer, a test solution at an upper layer, and a counter electrode for addressing detection at the top of the solution, the working electrode is bonded to the reference electrode, and the surface of the reference electrode is encapsulated with a hollow adhesive tape, insulating paint, or ink.

The disc-shaped working electrode and the ring-disc-shaped reference electrode are bonded together in an adhesive or hot-pressing mode to form an addressable two-electrode micropore array, the hollow part of the ring-disc-shaped reference electrode controls the area of the working electrode in a single micropore detection pool, and the surface of the ring-disc-shaped reference electrode is packaged by using a hollow adhesive tape, insulating paint or printing ink and is used for controlling the area of the reference electrode in the single micropore detection pool and separating different test sample solutions to form an addressable droplet array; the addressing detection is carried out by adopting the counter electrode, the mechanical addressing detection can be carried out on the liquid drop array to be detected by adopting a single counter electrode, or the complete three-electrode electrolytic cell can be respectively formed by the counter electrode array and all micropore detection cells, and then the detection is carried out by adopting an electronic addressing mode.

Preferably, the low-cost high-throughput electrochemical sensor according to the second aspect of the present invention is produced by the method according to the first aspect of the present invention.

In a third aspect of the present invention, the present invention provides a low-cost high-throughput photoelectrochemical sensor, which comprises a plurality of micropore array photoelectric detection cells arranged in an array, wherein each micropore array photoelectric detection cell comprises a bottom disc-shaped photoelectric working electrode, a middle ring disc-shaped photoelectric reference electrode/counter electrode, an upper photoelectric test solution and a small light spot light source for addressing detection at the top of the solution, the working electrode is bonded with the reference/counter electrode, and the surface of the reference electrode is encapsulated by a hollow adhesive tape, insulating paint or ink.

The working electrode and the reference/counter electrode are bonded together in an adhesive or hot-pressing mode, the hollow part of the annular disc-shaped reference/counter electrode controls the area of the working electrode in a single micropore detection pool, and the surface of the reference/counter electrode is packaged by using a hollow adhesive tape, insulating paint or printing ink and is used for controlling the area of the reference/counter electrode in the single micropore detection pool and separating different test sample solutions to form an addressable droplet array; the small light spot excitation light source is adopted for addressing detection, a single light source can be adopted for mechanically addressing detection of the liquid drop array to be detected, or the light source array and all micropore detection cells can be used for respectively forming complete photoelectric detection cells, and then the detection is carried out in an electronic addressing mode.

Preferably, the low-cost high-throughput photoelectrochemical sensor according to the third aspect of the present invention is prepared by the method according to the first aspect of the present invention.

In a fourth aspect of the invention, the invention provides a method for preparing the low-cost high-throughput electrochemical and photoelectrochemical sensor according to the first aspect of the invention or the low-cost high-throughput electrochemical sensor according to the second aspect of the invention or the low-cost high-throughput photoelectrochemical sensor according to the third aspect of the invention for use in the fields of electrochemistry, photoelectrochemistry and electrochemiluminescence in vitro diagnostics, drug screening and pesticide residue detection.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the preparation method of the low-cost high-flux electrochemical and photoelectrochemical sensor provided by the invention is simple and controllable, the production equipment cost is low, the automatic mass production is easy to realize, the detection device is integrated, the sample consumption is small, and the detection flux can be flexibly adjusted;

2. the preparation method of the low-cost high-flux electrochemical and photoelectrochemical sensor adopts schemes such as filtering and the like to construct a large-area, high-uniformity and high-conductivity film electrode and a photoelectric film, uses cutting technologies such as laser engraving and the like to construct a micropore array on the film electrode and the photoelectric film, and assembles the micropore array film electrode and the photoelectric film into an addressable double-electrode micropore array sensor with a stacked structure (as shown in figure 1). Based on addressing excitation of a liquid drop detection pool on the micropore array sensor by an electric or optical excitation signal, the detection efficiency of an optical 96/256 pore plate can be realized by adopting low-cost single-channel electrochemical detection equipment and an automatic addressing device;

3. the invention provides a low-cost high-throughput electrochemical sensor and a photoelectrochemical sensor, wherein a working electrode and a reference electrode are integrated together to form a micropore array, and a micro-volume test solution is introduced onto the micropore array to form a mutually isolated liquid drop array detection cell. In the addressing detection process, all the subarea liquid drop array detection cells of the sensor comprise working electrodes and reference electrodes, so that the potential stability of each subarea working electrode can be greatly improved, the noise interference can be reduced, and meanwhile, the structure can be compatible with signal output modes such as electrochemistry, photoelectrochemistry and electrochemiluminescence, so that the automatic addressing detection of different samples or the continuous dynamic monitoring of different micro-reaction systems can be realized.

4. The low-cost high-flux electrochemical sensor and the photoelectrochemical sensor provided by the invention can be used as a universal electrochemical biosensing platform and can be developed into a portable, low-cost, high-sensitivity and high-flux POCT/drug screening/pesticide residue detection system.

Drawings

FIG. 1 is a schematic diagram of the composition and basic structure of a single-channel addressable electrochemical and photoelectrochemical sensor;

FIG. 2 is a schematic diagram of the structure and operation mode of a single-channel addressable electrochemical sensor;

FIG. 3 is a schematic diagram of the structure and operation mode of a single-channel addressable photoelectrochemical sensor;

FIG. 4 is a pictorial view of a single channel 8 flux addressable photoelectrochemical sensor;

FIG. 5 is a schematic diagram of a low cost high throughput electrochemical sensor in operation;

FIG. 6 is a schematic structural view of a low-cost high-throughput photoelectrochemical sensor in operation;

FIG. 7 is a schematic diagram of the structure, physical map and test data of an addressed electrochemical sensor with different electrode compositions; fig. 7A is a schematic structural diagram, a real object diagram and test data of an addressable electrochemical sensor constructed by integrating a reference electrode and a working electrode; FIG. 7B is a schematic structural diagram, a physical diagram and test data of an addressable electrochemical sensor constructed by integrating a reference electrode and a counter electrode;

wherein the working electrode 1 a; reference electrode 2a, test solution 3 a; a counter electrode 4 a; a detection cell 5 a; a photoelectric working electrode 1 b; photoelectric reference/counter electrode 2 b; a photoelectric test solution 3 b; a small spot light source 4 b; and a photoelectric detection cell 5 b.

Detailed Description

The scheme of the invention will be explained with reference to the examples. It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The methods used are conventional methods known in the art unless otherwise specified, and the consumables and reagents used are commercially available unless otherwise specified. Unless otherwise defined, technical and scientific terms used herein have the same meaning as is familiar to those skilled in the art. In addition, any methods or materials similar or equivalent to those described herein can also be used in the present invention.

Example 1

Preparation of conductive material dispersion liquid:

dispersion 1

60mg of single-walled carbon nanotubes (SWNTs) were added to 500mL of a 5mM Sodium Dodecyl Sulfate (SDS) solution, ultrasonically dispersed in a 50W ultrasonic apparatus for 2 hours, and the resulting black solution was allowed to stand at room temperature for 2 days, and the upper black solution was collected to obtain a stock solution of SWNTs dispersed in the SDS aqueous solution.

Dispersion 2

The nano silver wire (AgNWs) dispersion solution is purchased from Nanjing Xiancheng nanometer material science and technology company, and the specific parameters are as follows: the diameter is 40nm, the length is 20-60 mu m, and the concentration is 20 mg/mL.

Dispersion 3

5.5mL of a 1 wt% chloroauric acid solution was added to 495mL of ultrapure water, stirred at room temperature for 5min, then 11mL of a 38.8mM sodium citrate solution was added, stirred at room temperature for 3min, and finally 5.5mL of 0.075 wt% NaBH prepared in a 38.8mM sodium citrate solution was added slowly₄The solution is stirred for 20min at room temperature to obtain 3nm nanogold (AuNPs) solution.

Preparing photoelectric material dispersion liquid:

dispersion 4

Mixing fullerene C with the mass ratio of 1:3₆₀Dissolving 4mg of a 1-hour ball-milled mixture with Congo Red (CR) in a 2mL plastic centrifuge tube filled with 1mL of water, ultrasonically dispersing for 1 minute, mixing with a 2M NaOH aqueous solution in an equal volume, centrifuging the mixed solution at 10000 r/min for 5 minutes, carefully removing an upper clear solution, and ultrasonically dispersing bottom sediment with 1mL of water; and repeating the alkali precipitation assisted centrifugal purification process until the upper layer solution is colorless, carefully washing the black and red muddy precipitate at the bottom twice with water, ultrasonically dispersing the muddy precipitate with water into 1mg/mL aqueous solution, and dialyzing for 1 day.

Dispersion 5

Solution A (1.82g Bi (NO)₃)₃·5H₂O in 25mL ethylene glycol), solution B (1.35g Na)₂S·9H₂O dissolved in 30mL of water), solution C (1.92g of urea in 20mL of water). Dropwise adding the solution B into the solution A, changing the solution into black under the stirring condition, then pouring the solution C into the mixed black solution, stirring, and transferring into a 100mL reaction kettle for reaction at 180 ℃ for 12 hours. Washing, drying, grinding into powder, and storing to obtain bismuth sulfide (Bi)₂S₃) An optoelectronic material. Taking 8mg of Bi₂S₃Adding the powder into 40mL of water, and ultrasonically dispersing for 0.5 hour to obtain more stable Bi of 0.2mg/mL₂S₃An aqueous dispersion solution.

Example 2

Filtration preparation of large-area SWNTs membrane electrode: taking 10mL of SWNTs dispersion liquid (dispersion liquid 1), ultrasonically dispersing into 100mL of water, forming a layer of uniform SWNTs film on a PVDF filter membrane with the diameter of 50mm soaked in ethanol in advance in a reduced pressure filtration mode, washing with a large amount of water to remove redundant SDS surfactant, and then drying in an oven at 60 ℃ for 2 hours to obtain the SWNTs film electrode with good conductivity.

Example 3

The filtration preparation of the large-area AgNWs film electrode comprises the following steps: 50 mu L of AgNWs solution (dispersion liquid 2) is taken and dispersed into 90mL of mixed liquid (8:1, v/v) of water and ethanol, a uniform AgNWs film is formed on a PVDF filter membrane which is soaked by ethanol in advance and has the diameter of 50mm by adopting a reduced pressure filtration mode, then a large amount of water is used for washing to remove the redundant dispersion aid, and then the AgNWs film electrode with good conductivity is obtained after being placed in an oven and dried for 2 hours at the temperature of 60 ℃.

Example 4

And (3) filtering preparation of the large-area nano porous gold film electrode: 100mL of AuNPs (dispersion 3) and 1M of NaCl aqueous solution are mixed in equal volume to ensure that gold nanoparticles are agglomerated, a layer of uniform nano-porous gold film is formed on a PVDF filter membrane which is soaked in ethanol in advance and has the diameter of 50mm by adopting a reduced pressure filtration mode, then a large amount of water is used for washing to remove redundant NaCl, and then the nano-porous gold film electrode with good conductivity is obtained after the nano-porous gold film is placed in an oven for drying for 2 hours at the temperature of 60 ℃.

Example 5

Bi₂S₃-filtration preparation of SWNTs composite photovoltaic films: 5mL of the dispersion 1 was added to 50mL of water, 40mL of the dispersion 5 was added and sonicated for 30min, and the mixture was filtered under reduced pressure onto the surface of the SWNTs thin film electrode prepared in example 2 to obtain Bi₂S₃SWNTs photovoltaic films, tested with a 500mW 405nm laser source and 0.1M Ascorbic Acid (AA), have a photocurrent of about 20. mu.A.

Example 6

C₆₀Filtering preparation of-CR/AgNWs composite photoelectric film: adding 50 μ L AgNWs (dispersion 2) into 90mL of a mixture of water and ethanol (8:1, v/v), adding 1mL of dispersion 4 into the AgNWs solution under stirring, mixing, filtering under reduced pressure to a pre-ethanol-soaked PVDF filter membrane with a diameter of 50mm, and adding a large amount of waterWashing to remove excessive auxiliary dispersant, and drying in oven at 60 deg.C for 2 hr to obtain C with good conductivity and photoelectric conversion efficiency₆₀-CR/AgNWs composite photovoltaic thin film. The photocurrent of the composite photoelectric film was measured using a 500mW 405nm laser source and 0.1M Ascorbic Acid (AA) and was about 120. mu.A.

Example 7

Preparation of addressing electrochemical sensor: the SWNTs film electrode prepared in the embodiment 2 is cut into a strip-shaped working electrode of 2cm multiplied by 1cm, PVDF on the back surface of the working electrode is fixed on a PET plastic sheet with the same size through a double faced adhesive tape, and the edge of the SWNTs layer on the front surface is led out by a nickel adhesive tape in a width of about 3mm to be used as an electrode lead; attaching double-sided adhesive tapes to the PVDF on the back surface of the AgNWs thin film electrode prepared in the embodiment 3, constructing a through round hole array with the aperture of 2mm and the interval of 2mm on the electrode by using a laser engraving technology, cutting the through round hole array into a 2cm multiplied by 1cm long strip-shaped reference electrode, and leading out the edge of the AgNWs layer on the front surface by using a nickel adhesive tape with the width of about 3mm as an electrode lead; and then, an AgNWs thin-film electrode with a circular hole array is adhered to the front surface of the SWNTs working electrode through a double-sided adhesive on the back surface of the electrode, and the surface of the electrode is further covered with a laser-engraved PVC circular hole adhesive tape with the aperture of 3mm and the interval of 1mm, so that an 8-flux addressable double-electrode micropore array electrochemical sensor with a working electrode 1a with the diameter of 2mm at the bottom, an AgNWs quasi-reference electrode 2a with the diameter of 0.5mm at the middle ring and a PVC circular hole with the diameter of 3mm at the upper layer is prepared (the structure and the working mode schematic diagram of the single-channel addressable electrochemical sensor are shown in figure 2).

Example 8

Auto-addressed detection of addressed electrochemical sensors: welding a platinum wire with the length of about 2cm and the diameter of 0.3mm to the tail end of the thin copper rod, sealing the outer layer of the platinum wire with hydrophobic nail polish, and cutting off a platinum microdisk with the tail end with the diameter of 0.3mm to serve as a counter electrode 4 a; the addressable two-electrode electrochemical sensor prepared in example 7 was placed on a sample stage of an innovative three-dimensional CR-83D printer, 6 μ L of the test solution 3a was dropped into each microwell array 5a of the sensor, then the Pt microdisk counter electrode described above was fixed to the print head of the 3D printer, and the working electrode 1a, the reference electrode 2a, and the counter electrode 4a were connected to an electrochemical workstation, respectively, and the droplet array test solution on the sensor was automatically addressed by the counter electrode on the print head controlled by a computer. In the addressing process of the counter electrode, a complete three-electrode electrolytic cell system is formed when the counter electrode contacts each liquid drop, the liquid drop detection is completed after the contact is separated, and then the liquid drop is continuously moved to the next liquid drop, so that the automatic high-flux electrochemical sensing is realized by utilizing the ampere detection principle and the mechanical addressing of the counter electrode. Fig. 7A is a schematic structural diagram, a schematic physical diagram and test data of the addressable electrochemical sensor constructed by integrating the reference electrode and the working electrode in this embodiment.

By contrast, the filamentous reference electrode and the counter electrode are wound and insulated and packaged together through Parafilm, and the microdisk reference electrode and the counter electrode which are isolated from each other are exposed at the ends of the microdisk reference electrode and the counter electrode are cut off, so as to construct the addressable electrochemical sensor, wherein the schematic structural diagram, the physical diagram and the test data are shown in fig. 7B.

As can be seen from fig. 7, in the addressable electrochemical sensor constructed in this embodiment, in the test process, the working electrode and the reference electrode in each sample well are always in solution connection, so that the potential of the working electrode can be better stabilized, and the signal-to-noise ratio can be improved; meanwhile, when a single counter electrode is adopted for addressing, the solution connection condition caused in the addressing process can be effectively avoided due to the small size of the tail end of the counter electrode. On the contrary, if the counter electrode and the reference electrode are integrated together, when the working electrode is addressed, the potential of the working electrode is not accurately controlled, the base line is not flat and the signal-to-noise ratio is poor because the working electrode and the reference electrode are not connected in the test process; meanwhile, the tail end of the counter electrode and the reference electrode assembly is large in size, and adjacent droplets are easily connected together in the addressing detection process, so that the effect of droplet addressing high-throughput detection is lost.

Example 9

Preparation of addressing photoelectrochemical sensor: c prepared in example 6₆₀Cutting the-CR/AgNWs composite photoelectric film into a 2cm multiplied by 1cm strip-shaped working electrode, fixing the PVDF on the back surface of the working electrode on a PET plastic sheet with the same size through a double faced adhesive tape, and fixing the PVDF on the front surface C of the working electrode₆₀The edge of the CR/AgNWs layer is drawn out by a nickel adhesive tape in a width of about 3mm to be used as an electrode lead; the PVDF tape on the back of the AgNWs thin film electrode prepared in example 3 is pasted with a double-sided adhesive tape, and a hole is formed on the double-sided adhesive tape by using a laser engraving technologyCutting a through circular hole array with the diameter of 2mm and the distance of 2mm into a 2cm multiplied by 1cm strip-shaped reference electrode, and leading out the edge of the front AgNWs layer with the width of about 3mm by using a nickel adhesive tape to be used as an electrode lead; then, the AgNWs thin film reference electrode with the round hole array is adhered to the C through the back double-sided adhesive₆₀The front surface of the CR/AgNWs working electrode is further covered with a laser-engraved PVC round hole adhesive tape with the aperture of 3mm and the interval of 1mm, so that a single-channel 8-flux addressable double-electrode micropore array photoelectrochemical sensor with the bottom diameter of 2mm, the middle ring diameter of 0.5mm AgNWs reference/counter electrode 2b and the upper layer diameter of 3mm PVC round holes is prepared, the schematic structure and the working mode of the single-channel 8-flux addressable photoelectrochemical sensor are shown in figure 3, and figure 4 is a real object diagram of the single-channel 8-flux addressable photoelectrochemical sensor. Although this embodiment shows only the photoelectrochemical sensor having the detection flux of 8, the flux thereof may be extended as necessary. For example, a common PVDF (polyvinylidene fluoride) microporous filter membrane with the diameter of 50mm is used for constructing a paper-shaped addressable photoelectrochemical sensor with the detection flux reaching 42.

Example 10

Ink-jet printing preparation of addressing photoelectrochemical sensors: the fullerene photoelectric material (dispersion liquid 5) is centrifuged at 10000 r/min for 30min, an upper layer stable solution is carefully collected to be used as special ink of an ink-jet printer, and a photoelectric material array with the diameter of 2mm and the interval of 2mm is formed on the nano-porous gold film electrode or other large-area flexible working electrodes prepared in the example 4 in an ink-jet mode. Cutting the nano-gold conductive layer into a 2cm multiplied by 1cm strip-shaped working electrode, fixing PVDF on the back of the working electrode on a PET plastic sheet with the same size through a double faced adhesive tape, and leading out the edge of the front nano-gold conductive layer with the width of about 3mm by using a nickel adhesive tape as an electrode lead; attaching double-sided adhesive tapes to the PVDF on the back surface of the AgNWs thin film electrode prepared in the embodiment 3, constructing a through round hole array with the aperture of 2mm and the interval of 2mm on the electrode by using a laser engraving technology, cutting the through round hole array into a 2cm multiplied by 1cm long strip-shaped reference electrode, and leading out the edge of the AgNWs layer on the front surface by using a nickel adhesive tape with the width of about 3mm as an electrode lead; then, the AgNWs thin film reference electrode with the round hole array is adhered to the C through the back double-sided adhesive₆₀-CR array modified nano porous gold working electrode positive electrodeAnd the hollow round holes of the reference electrode just cover the round photoelectric array of the working electrode. And finally, further covering the surface of the reference electrode with a laser engraving PVC round hole adhesive tape with the aperture of 3mm and the interval of 1mm, thereby preparing the 8-flux addressable double-electrode micropore array photoelectrochemical sensor with the bottom diameter of 2mm, the middle ring diameter of 0.5mm AgNWs reference/counter electrode 2b and the upper layer diameter of 3mm PVC round holes.

Example 11

Automatic addressing detection of addressed photoelectric chemical sensors: the addressable photoelectric sensor directly adopts a two-electrode system, namely C prepared in example 9₆₀the-CR/AgNWs working electrode + AgNWs reference/counter electrode can form a complete photoelectrochemical sensor without an additional counter electrode and has a structure similar to a solar cell. The sensor is placed on the sample stage of an inventive three-dimensional CR-83D printer, 6. mu.L of a test solution 3b containing an electron donor ascorbic acid is dropped onto each microwell array 5b of the sensor, after which a small spot laser light source 4b (e.g., 50mW, 650nm) is fixed to the print head of the 3D printer, and C is applied₆₀the-CR/AgNWs electrode is connected with a working electrode clamp of an electrochemical workstation, the AgNWs electrode is simultaneously connected with a reference electrode and a counter electrode clamp, and a light source on a printing head is controlled by a computer to automatically address the liquid drop array test solution on the sensor. In the addressing detection process of the exciting light, when the exciting light irradiates on the working electrode, a complete two-electrode micro-solar cell type photoelectric detection cell is formed, the liquid drop detection is completed after the light source is separated from the working electrode, and then the liquid drop detection device continuously moves to the next liquid drop, so that the automatic high-flux photoelectrochemical sensing is realized by utilizing the photoelectric detection principle and the non-contact automatic addressing excitation of the light source.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A preparation method of a low-cost high-flux electrochemical and photoelectric chemical sensor is characterized by comprising the following steps:

2. The method for preparing a low-cost high-throughput electrochemical and photoelectrochemical sensor according to claim 1, wherein in the step 1), the conductive material is a composite conductive material consisting of one or more of gold, silver, platinum, carbon nanotubes, nanoparticles of graphene, nanowires, nanotubes and nanosheets; preferably, in the step 1), the photoelectric material is selected from one of fullerene, bismuth sulfide, silver sulfide and bismuth vanadate or a composite photoelectric material composed of one or more of nano-gold, carbon nano-tube and graphene.

3. The method for preparing a low-cost high-throughput electrochemical and photoelectrochemical sensor according to claim 1, wherein the step 1) comprises depositing a dispersion of a conductive material on the surface of a microporous or nanoporous filter membrane by filtration, and drying to form a large-area, highly uniform, and highly conductive membrane electrode.

4. The method for preparing a low-cost high-throughput electrochemical and photoelectrochemical sensor according to claim 1, wherein in the step 1), the inkjet printing scheme is that after the dispersion of the conductive material or the precursor thereof is deposited on the surface of the substrate by inkjet printing, the substrate is dried to form the large-area, high-uniformity and high-conductivity thin film electrode.

5. The method for preparing a low-cost high-throughput electrochemical and photoelectrochemical sensor as claimed in claim 1, wherein in the step 1), the filtering scheme is to deposit the conductive material and the photoelectric material on the surface of the microporous or nanoporous filter membrane by mixing or layered filtering, and then drying to form the photoelectric thin film with large area, high uniformity and high conductivity.

6. The method for preparing a low-cost high-throughput electrochemical and photoelectrochemical sensor according to claim 1, wherein in the step 1), the inkjet printing scheme is to inkjet print the mixed solution of the conductive material and the photoelectric material onto the substrate, or to inkjet print a large-area continuous conductive film, then inkjet print a continuous or patterned photoelectric material layer, and form a large-area, highly uniform and highly conductive photoelectric film or pattern after drying.

7. The method for preparing a low-cost high-throughput electrochemical and photoelectric chemical sensor of claim 3 or 5, wherein in the step 1), the material of the microporous or nanoporous filter membrane is selected from cellulose, polytetrafluoroethylene, polyvinylidene fluoride, nylon, polyether, polysulfone, alumina or derivatives thereof.

8. The low-cost high-flux electrochemical sensor is characterized by comprising a plurality of micropore array detection cells (5a) which are arranged according to an array, wherein each micropore array detection cell (5a) comprises a disc-shaped working electrode (1a) at the bottom layer, a ring-disc-shaped reference electrode (2a) at the middle layer, a test solution (3a) at the upper layer and a counter electrode (4a) for addressing detection at the top of the solution, the working electrode (1a) is bonded with the reference electrode (2a), and the surface of the reference electrode (2a) is packaged by hollow adhesive tape, insulating paint or printing ink;

preferably, the low-cost high-flux electrochemical sensor is prepared by the method of claims 1-8.

9. The low-cost high-flux photoelectrochemical sensor is characterized by comprising a plurality of micropore array photoelectric detection cells (5b) which are arranged in an array, wherein each micropore array photoelectric detection cell (5b) comprises a disc-shaped photoelectric working electrode (1b) at the bottom layer, a ring disc-shaped photoelectric reference electrode/counter electrode (2b) at the middle layer, a photoelectric test solution (3b) at the upper layer and a small light spot light source (4b) for addressing detection at the top of the solution, the working electrode (1b) is bonded with the reference/counter electrode (2b), and the surface of the reference electrode (2b) is packaged by a hollow adhesive tape, insulating paint or ink;

preferably, the low-cost high-flux photoelectrochemical sensor is prepared by the method of claims 1-8.

10. Use of the low-cost high-throughput electrochemical and photoelectrochemical sensor of claims 1-7 or the low-cost high-throughput electrochemical sensor of claim 8 or the low-cost high-throughput photoelectrochemical sensor of claim 10 in the fields of electrochemistry, photoelectrochemistry, and electrochemiluminescence in vitro diagnostics, drug screening, and pesticide residue detection.