A triazophos double photoelectrode self-powered photoelectrochemical sensor and a preparation method thereof

Abstract

This invention discloses a dual-photoelectrode self-powered photoelectrochemical sensor for detecting triazophos and its preparation method. Specifically, it relates to a dual-photoelectrode self-powered molecularly imprinted photoelectrochemical sensor based on a CuO / COF / ITO photoanode and a photocathode operating based on a "lock and key" mechanism of cobalt iron borate (CBFO) molecularly imprinted polymer, for the highly sensitive and selective detection of triazophos. Furthermore, the sensor, combined with molecularly imprinted polymer recognition technology, possesses unique technical advantages in the specific recognition and signal conversion of target molecules, selectively binding to template molecules and exhibiting excellent selective recognition performance. The method of this invention is used for the detection of the organophosphorus pesticide triazophos and is simple, rapid, sensitive, and accurate. The instrument is simple, inexpensive, and suitable for miniaturization, overcoming the disadvantages of traditional chromatographic methods such as expensive instruments, complex sample pretreatment, and difficulty in rapid on-site screening. The dual-photoelectrode self-powered system achieves self-powered detection through the synergistic effect of the photoanode and photocathode, and has broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of dual-electrode self-powered photoelectrochemical sensors, specifically relating to a triazole thionylphosphine dual-electrode self-powered photoelectrochemical sensor, its preparation method, and its application. Background Technology

[0002] In recent years, with the widespread application of organophosphorus pesticides in agricultural production, it has been found that their use causes pollution hazards, easily leading to air, water, soil, and agricultural product pollution, ultimately harming the ecosystem. Even at extremely low concentrations, these residues or their metabolites can still accumulate through the food chain, exerting neurotoxicity on organisms, and long-term exposure may increase the risk of cancer, posing a serious threat to human health. Triazophos (TAP) is an organophosphorus insecticide with high residue and high toxicity, widely used in agriculture for pest and disease control in wheat, vegetables, fruits, and tea. TAP has good chemical and optical stability, is moderately toxic to mammals, but is highly toxic to fish and bees. TAP residues in products and the environment pose certain harms to human health and the ecosystem. TAP can also inhibit some serine hydrolases, such as neuropathic target esterases, lipases, and endogenous cannabinoid hydrolases, threatening the endocrine, metabolic, nervous systems, liver, and kidneys of organisms. Therefore, it is essential to develop a highly sensitive, highly selective, rapid, simple, and low-cost detection method for pesticide residue analysis.

[0003] Currently, methods for detecting TAP include high-performance liquid chromatography (HPLC), gas chromatography (GC), enzyme-linked immunosorbent assay (ELISA), enzyme biosensors, ultraviolet spectrophotometry, and chemiluminescence immunoassay. These methods offer high reliability and accuracy, but their drawbacks include the need for expensive equipment, complex sample processing, trained professionals, and difficulty in on-site detection. In contrast, photoelectrochemically imprinted sensors not only possess the advantages of traditional methods but also offer features such as low detection limits, fast response speeds, high selectivity, ease of operation, and on-site detection capabilities, making them worthy of widespread application. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a method for preparing a self-powered photoelectrochemical sensor for detecting triazole thionylphosphide using a dual electrode. This method is simple to operate and easy to promote. Summary of the Invention

[0005] This invention aims to provide a dual-photoelectrode self-powered photoelectrochemical sensor for detecting triazine thiophanate and its preparation method, addressing the problems of expensive equipment, complex operation, and difficulty in rapid on-site screening in existing detection technologies. The sensor is based on a dual-photoelectrode self-powered system, and its working principle is based on the synergistic photoelectric response of the photoanode (n-type semiconductor) and photocathode (p-type semiconductor), achieving efficient detection without an external power supply. For example, a cobalt borate-doped iron (CBFO) photocathode loaded with a molecularly imprinted recognition element can selectively enrich triazine thiophanate using visible light, generating a modulation signal through the directional transport of photogenerated electrons; while the CuO / COF photoanode possesses excellent broad-spectrum light absorption and efficient carrier separation characteristics, providing current for system operation. Molecular imprinting technology has unique technical advantages in the specific recognition of target molecules. The synthesized molecularly imprinted polymers (MIPs) exhibit predictability and high selectivity for target molecules, specifically recognizing template molecules and demonstrating excellent selective recognition capabilities and sensing performance. The technical problem that this invention also aims to solve is to provide the application of the above-mentioned photoelectrochemical sensor in the field of detection, which has the characteristics of being simple, fast, sensitive, accurate, and having simple and low-cost detection equipment.

[0006] Based on this, the present invention constructs a bipolar self-powered system by using CuO / COF-modified indium tin oxide (ITO) conductive glass as the photoanode and cobalt iron borate (CBFO)-modified ITO as the photocathode. It also constructs a dual-electrode self-powered photoelectrochemical sensor by combining the specific recognition ability of molecularly imprinted polymers. By combining the signal amplification effect and the effect of increasing the specific surface area of ​​nanomaterials, rapid and sensitive detection of triazine thionylphosphide can be achieved, which is of great significance.

[0007] This invention optimizes the composition (template molecule: functional monomer), pH of the substrate, elution time, and recognition time of the electropolymerization molecularly imprinted polymerization solution to obtain the optimal conditions: a template molecule to functional monomer concentration ratio of 1:5, a pH of 6, an elution time of 5 min, and a recognition time of 10 min. Under these optimal conditions, the MIP / CBFO / ITO electrode exhibits excellent photoelectrochemical response.

[0008] The technical solution of this invention is as follows: A triazole thionylphosphonate dual-electrode self-powered photoelectrochemical sensor, characterized by comprising the following steps: (1) Place CuSO4·5H2O and NaOH in a mortar and grind until all the blue solid reacts to form a black solid; (2) The solid from step (1) was then washed sequentially with ultrapure water and anhydrous ethanol, filtered, and dried. Nano-CuO was obtained; (3) Weigh melamine and glutaraldehyde, add dimethyl sulfoxide, and dissolve by sonication; (4) Add the product obtained in step (2) to the suspension in step (3), mix evenly, and heat in a constant temperature furnace; after cooling, wash the sample with water and anhydrous ethanol and adjust the pH value; finally, obtain CuO / COF composite material by vacuum freeze drying. (5) The product obtained in step (4) is mixed in Nafion solution and ultrasonically treated to obtain a suspension; (6) The ITO conductive glass was ultrasonically treated with toluene, acetone, ethanol and ultrapure water respectively, and then placed in an oven to dry before modification. (7) The suspension from step (5) is drop-coated onto ITO conductive glass and dried in an oven to obtain CuO / COF / ITO photoanode; (8) Add bismuth nitrate pentahydrate, cobalt nitrate trihydrate and ferric nitrate nonahydrate to a solution of nitric acid to obtain an electrodeposition precursor solution; (9) The suspension from step (8) was gradually added to NaOH solution to adjust the pH value, and Fe-CBO solution was obtained. (10) Use the solution from step (9) as the electrolyte, ITO as the working electrode, saturated calomel electrode as the reference electrode, Pt column electrode as the counter electrode, and apply a fixed potential. (11) The electrode obtained in step (10) is thoroughly cleaned with deionized water; then it is placed in a muffle furnace for annealing to obtain CBFO / ITO; (12) The electrode obtained in step (10) is used as a template molecule of triazole thiophosphorus and a functional monomer of pyrrole to form a molecularly imprinted polymer film on the electrode surface by electropolymerization. (13) Immerse the electrode from step (12) in an acetic acid-methanol mixture to elute and remove the template molecule TAP. After treatment, the molecularly imprinted polymer modified electrode MIP / CBFO / ITO is obtained. (14) Identify the electrode MIP / CBFO / ITO prepared in step (13) in triazole thionine solution.

[0009] As a preferred technical solution of this application, in step (1), the amount of CuSO4·5H2O is 2.5 g and the amount of NaOH is 1.4 g.

[0010] As a preferred technical solution of this application, the drying temperature in step (2) is 60 ℃.

[0011] As a preferred technical solution of this application, in step (3), the amount of melamine used is 0.3780 g, the amount of glutaraldehyde used is 0.1010 g, and the amount of dimethyl sulfoxide used is 10 mL.

[0012] As a preferred technical solution of this application, in step (4), the constant temperature furnace temperature is 180 ℃, the heating time is 3 h, the pH value is 7~8, and the vacuum freeze drying time is 48 h.

[0013] As a preferred technical solution of this application, the ultrasonic treatment time in step (5) is 20 min.

[0014] As a preferred technical solution of this application, the ultrasonic treatment time in step (6) is 1 h.

[0015] As a preferred technical solution of this application, the drying temperature of the oven in step (7) is 60 ℃.

[0016] As a preferred technical solution of this application, the HNO3 solution in step (8) is 10%; the concentration of bismuth nitrate pentahydrate is 6.0 mM, the concentration of cobalt nitrate trihydrate is 4.0 mM and the concentration of ferric nitrate nonahydrate is 2.0 mM.

[0017] As a preferred technical solution of this application, the pH value of step (9) is 12.

[0018] As a preferred technical solution of this application, the fixed potential in step (10) is 5 V and the duration is 150 s.

[0019] As a preferred technical solution of this application, the temperature of the muffle furnace in step (11) is set to 500 ℃ and the annealing time is 2 h.

[0020] As a preferred technical solution of this application, the concentration of TAP solution in step (12) is 0.1 mM and the concentration of pyrrole is 0.5 mM.

[0021] As a preferred technical solution of this application, the volume ratio of the acetic acid and methanol mixed solution in step (13) is 2:8.

[0022] As a preferred technical solution of this application, the concentration of triazole thiophanate solution in step (14) is 0.1 nM.

[0023] The present invention also includes a dual-electrode self-powered photoelectrochemical sensor obtained by the above-described preparation method.

[0024] The present invention also includes the application of the above-mentioned dual-electrode self-powered photoelectrochemical sensor in the field of detection.

[0025] This invention also includes the application of the aforementioned dual-electrode self-powered photoelectrochemical sensor in the field of detection, characterized by comprising the following steps: 1) Add a buffer solution containing 0.1 M PBS (pH 6.0) to the electrolytic cell; 2) The dual-electrode system consisting of the MIP / CBFO / ITO electrode and the COF / CuO / ITO electrode as described in claim 1 is placed in the above-mentioned electrolytic cell. The light source is a 500 W high-brightness xenon lamp, and photoelectric switching tests are performed under no bias voltage. The photocurrent signal is detected by an electrochemical workstation and displayed on a computer.

[0026] The basic idea of ​​this invention is as follows: CuO / COF powder is mixed in Nafion solution. After ultrasonic treatment, the mixture is modified onto ITO conductive glass; a CBFO film is obtained by electrodeposition and annealing to obtain a CBFO / ITO photocathode electrode. The template molecule triazole thiophosphorus and the functional monomer pyrrole molecule are imprinted onto the CBFO / ITO photocathode electrode by electropolymerization. Triazole thiophosphorus is eluted with a 2:8 volume ratio acetic acid and methanol mixture to obtain the sensor MIP / CBFO / ITO. Triazole thiophosphorus is detected using photocurrent testing (it) in 0.1 M PBS solution (pH 6.0). The electrode is eluted with a 2:8 volume ratio acetic acid and methanol mixture for 5 min, then identified in a recognition solution containing a certain concentration of triazole thiophosphorus for 10 min. The working electrode is placed in the base solution, and photocurrent testing is performed under a 500 W high-brightness xenon lamp without bias voltage. Before the next it scan, the electrode is eluted to ensure the working electrode surface is clean. The CuO / COF photoanode possesses excellent broad-spectrum light absorption and efficient carrier separation, providing current for system operation. The CBFO / ITO photocathode loaded with a molecularly imprinted recognition element can selectively enrich triazophos using visible light, generating a modulation signal through the directional transport of photogenerated electrons. This demonstrates that the MIP / CBFO / ITO electrode exhibits excellent photoelectrochemical analytical capabilities for the detection of triazophos.

[0027] The advantages of this invention compared to the prior art are as follows: 1. This invention successfully uses CuO / COF composite material as a photoanode. This material has broad-spectrum absorption and high carrier separation efficiency, which can provide a stable and enhanced photocurrent signal, thereby improving the detection sensitivity of the sensor.

[0028] 2. Cobalt iron borate-modified electrode (CBFO / ITO) serves as a photocathode substrate, exhibiting excellent photoelectric properties and stability. After loading with molecularly imprinted polymers, it can achieve highly selective recognition and enrichment of triazine thiophosphate molecules, enhancing the specificity of the sensor.

[0029] 3. This invention combines molecular imprinting technology with an optochemical sensing platform. By electropolymerizing triazolium phosphate as a template molecule and pyrrole as a functional monomer, a molecularly imprinted layer with specific recognition sites is constructed on the electrode surface. This design not only fully leverages the high selectivity and reusability of molecular imprinting technology itself, but also, through synergy with the optochemical detection mechanism, enables the entire sensor system to possess the comprehensive advantages of rapid response, convenient operation, and high sensitivity.

[0030] 4. A self-powered photoelectrochemical sensing system based on a MIP / CBFO / ITO photocathode and a CuO / COF / ITO photoanode was constructed, enabling ultrasensitive detection of triazophos without an external power supply. This system exhibits strong signal amplification, low detection limit, and wide linear range, demonstrating good accuracy and reliability in actual sample detection. This proves the sensor's application potential in rapid pesticide residue detection and provides a new approach to replace traditional, complex, and expensive detection methods. Attached Figure Description Figure 1 This is a schematic diagram illustrating the construction of the triazole thionylphosphine dual-electrode self-powered photoelectrochemical sensor of the present invention.

[0031] Figure 2 This is a template / monomer ratio optimization curve for the fabrication conditions of the triazole thionylphosphine dual-electrode self-powered photoelectrochemical sensor in Example 1 of the present invention.

[0032] Figure 3 The pH optimization curve of the base solution for the fabrication conditions of the triazole thiophos dual-electrode self-powered photoelectrochemical sensor in Example 2 of this invention is shown.

[0033] Figure 4 This is a curve showing the optimized elution time for the fabrication conditions of the triazole thiophos dual-electrode self-powered photoelectrochemical sensor in Example 3 of the present invention.

[0034] Figure 5 This is a curve showing the optimized recognition time for the fabrication conditions of the triazole thiophos dual-electrode self-powered photoelectrochemical sensor in Example 4 of the present invention.

[0035] Figure 6 This is the detection curve of the triazophos standard sample in Example 5 of the present invention. Detailed Implementation Example

[0036] 1. Fabrication of a triazole thionylphosphonate dual-electrode self-powered photoelectrochemical sensor: (1) Place 2.5 g CuSO4·5H2O and 1.4 g NaOH in a mortar and grind until all the blue solid reacts to form a black solid; (2) The solid from step (1) was then washed sequentially with ultrapure water and anhydrous ethanol, and dried at 60 °C to obtain nano-CuO; (3) Weigh 0.3780 g of melamine and 0.1010 g of glutaraldehyde, add 10 mL of dimethyl sulfoxide, and dissolve by sonication; (4) Add the product obtained in step (2) to the suspension in step (3), mix evenly, and heat in a constant temperature furnace at 180 °C; after cooling, wash the sample with water and anhydrous ethanol, and adjust the pH value to 7~8; finally, obtain CuO / COF composite material by vacuum freeze drying for 48 h. (5) The product obtained in step (4) was mixed in Nafion solution and sonicated for 20 min to obtain a suspension; (6) ITO conductive glass was ultrasonically treated with toluene, acetone, ethanol and ultrapure water for 1 h and then placed in an oven to dry for modification. (7) The suspension from step (5) is drop-coated onto ITO conductive glass and dried in an oven at 60 °C to obtain a CuO / COF / ITO photoanode; (8) Add 6.0 mM bismuth nitrate pentahydrate, 4.0 mM cobalt nitrate trihydrate and 2.0 mM ferric nitrate nonahydrate to a 10% nitric acid solution to obtain an electrodeposition precursor solution; (9) Gradually add 3 M NaOH solution to the suspension from step (8) to adjust the pH value to 12, and obtain Fe-CBO solution; (10) Use the solution from step (9) as the electrolyte, ITO as the working electrode, saturated calomel electrode as the reference electrode, Pt column electrode as the counter electrode, and apply a fixed potential of 5 V for 150 s. (11) The electrode obtained in step (10) was thoroughly cleaned with deionized water; then it was placed in a muffle furnace at 500 °C for annealing for 2 h to obtain CBFO / ITO; (12) Electropolymerize 0.1 mM triazole thiophosphate and 0.5 mM pyrrole on the electrode surface obtained in step (10); (13) To remove the template molecule TAP, the electrode in step (12) was eluted in a 2:8 acetic acid-methanol mixed solution for 5 min to obtain the molecularly imprinted polymer modified electrode MIP / CBFO / ITO. (14) The MIP / CBFO / ITO electrode prepared in step (13) was identified in 0.1 nM triazole thionine solution for 10 min.

[0037] Figure 2This figure illustrates the effect of the molar ratio of triazole thiophos template molecules to pyrrole functional monomers on the response current in Example 1. The figure shows that the maximum photocurrent (it) occurs when the molar ratio of triazole thiophos template molecules to pyrrole functional monomers is 1:4. The photocurrent increases between molar ratios of 1:3 and 1:5, but decreases with further increases in concentration. The molar ratio of template molecules to functional monomers determines the number of imprinted sites in the MIP layer. Insufficient functional monomers result in an insufficient number of binding sites available for the template molecules. Conversely, excessive monomers lead to an overly thick MIP film, causing many binding sites to be buried in the polymer matrix and unable to bind to the template molecules. Therefore, a molar ratio of triazole thiophos to pyrrole of 1:5 was chosen as the optimal concentration ratio for the subsequent photoelectrochemical experiments.

[0038] Example 2: The MIP / CBFO / ITO electrode obtained in Example 1, based on the optimal electropolymerized triazole thiophos template and pyrrole monomer concentration ratio of 1:5, was applied for detection. The analytical methods included: A dual-electrode system was constructed using MIP / CBFO / ITO and CuO / COF electrodes. The molar ratio of triazole thiophosphorus template molecules to pyrrole functional monomers was 1:5. The pH values ​​of the substrate solution were 3, 4, 5, 6, and 7. 0.1 M PBS buffer solutions with different pH values ​​(pH values ​​3, 4, 5, 6, and 7) were added to the electrolytic cell, and then optimization was performed using IT tests.

[0039] Figure 3 The graphs show the photocurrent (it) values ​​corresponding to pH 3, 4, 5, 6, and 7 in Example 2. It can be seen from the graphs that the photocurrent change is relatively large at pH 6. Therefore, pH 6 was chosen as the optimal pH value for the substrate for subsequent photoelectrochemical experiments.

[0040] Example 3: The MIP / CBFO / ITO electrode obtained in Example 1, based on the optimal electropolymerized triazole thiophos template and pyrrole monomer concentration ratio of 1:5, was applied for detection. The analytical methods included: A two-electrode system was constructed using MIP / CBFO / ITO and CuO / COF electrodes. The molar ratio of triazole thiophosphorus template molecules to pyrrole functional monomers was 1:5, and the pH of the underlying solution was 6. Electrode elution times were 3 min, 5 min, 7 min, 10 min, and 14 min. 0.1 M PBS buffer (pH 6.0) was added to the electrolytic cell, and the system was optimized using the iterative method (itM).

[0041] Figure 4The figure shows the effect of elution time on photocurrent response in Example 3. As can be seen from the figure, the photocurrent change is largest when the elution time is 5 min. With further increases in elution time, the photocurrent change decreases. Furthermore, the photocurrent change tends to plateau between 10 min and 15 min, indicating that 5 min is the optimal elution time. Extending the elution time cannot guarantee the elution of triazole thion from the MIP membrane. Therefore, a elution time of 5 min was chosen as the optimal elution time for the subsequent photoelectrochemical experiments.

[0042] Example 4: A dual-electrode system was constructed using MIP / CBFO / ITO and CuO / COF electrodes. The molar ratio of triazole thiophosphorus template molecules to pyrrole functional monomers was 1:5, the pH of the substrate solution was 6, and the electrode elution time was 5 min. The electrode recognition times were 5 min, 9 min, 10 min, 12 min, and 15 min. 0.1 M PBS buffer solution (pH 6.0) was added to the electrolytic cell, and the system was optimized using the iterative method (itM).

[0043] Figure 5 This illustrates the effect of recognition time on photocurrent response in Example 4. The binding of the MIP film to the triazole thiophosphate molecule depends on hydrogen bonding, which requires a certain amount of time to complete. As shown in the figure, the photocurrent change increases with increasing recognition time, reaching its maximum at 10 min, indicating that the "cavities" in the MIPs are fully filled. Therefore, a recognition time of 10 min was chosen as the optimal recognition time for subsequent photoelectrochemical experiments.

[0044] Example 5: To examine the reliability of this method in practical application, the content of triazophos in cucumbers, lettuce, and apples purchased from a local supermarket was tested, and the results are shown in Table 1. Figure 6 As shown, photoelectrochemical (it) tests were performed on the triazophos standard solution under optimal conditions, and a standard curve was plotted. The triazophos concentration was 1.0 × 10⁻⁶. -5 Within the range of ~1.0 nM, the change in photocurrent response (ΔI) is related to the triazine concentration C. TAP The negative logarithm shows a good linear relationship, and the linear equation is: ΔI(mA) = -2 × 10 -3 Log(C / nM) + 1.05 × 10 -3 (R 2 =0.9888), the detection limit is 2.07×10 -6 nM (S / N = 3).

[0045] Table 1. Determination of the recovery rate of triazophos in the samples (n = 3)

Claims

1. This invention is a dual-photoelectrode self-powered photoelectrochemical sensor for detecting triazine thiophosphate. The sensor utilizes a CuO / COF composite material as the photoanode, which has broad-spectrum absorption and high carrier separation efficiency, providing a stable photocurrent for the system; and uses cobalt iron borate (CBFO) as the photocathode substrate, loaded with molecularly imprinted polymers (MIPs), which have a specific recognition function for triazine thiophosphate molecules. The self-powered system constructed by combining the two can achieve ultrasensitive detection of triazine thiophosphate without an external power source. The composite material is a CBFO film (2) on the conductive substrate (1) as the photocathode. On the surface of the CBFO electrode, a molecularly imprinted polymer film (3) is formed by electropolymerization using triazine thiophosphate as the template molecule and pyrrole as the functional monomer. The material is a CuO / COF composite material (5) on the conductive substrate (4) as the photoanode.

2. A method for preparing a dual-photoelectrode self-powered photoelectrochemical sensor as described in claim 1, characterized in that, Includes the following steps: (1) Place CuSO4·5H2O and NaOH in a mortar and grind until all the blue solid reacts to form a black solid. Then wash with ultrapure water and anhydrous ethanol respectively, filter and dry to obtain nano CuO. (2) Weigh melamine and glutaraldehyde, add dimethyl sulfoxide, and dissolve by sonication; (3) Add the product obtained in step (1) to the suspension in step (2), mix evenly, and heat in a constant temperature furnace; after cooling, wash the sample with water and anhydrous ethanol and adjust the pH value; finally, obtain CuO / COF composite material by vacuum freeze drying, then mix it in Nafion solution, sonicate it, and obtain a suspension. (4) The ITO conductive glass was ultrasonically treated with toluene, acetone, ethanol and ultrapure water respectively and then placed in an oven to dry for modification; then the suspension in step (3) was drop-coated onto the ITO conductive glass and dried in an oven to obtain CuO / COF / ITO photoanode. (5) Add bismuth nitrate pentahydrate, cobalt nitrate trihydrate and ferric nitrate nonahydrate to nitric acid solution to obtain electrodeposition precursor solution, and then gradually add NaOH solution to adjust pH value to obtain Fe-CBO solution; (6) Using the solution from step (5) as the electrolyte, ITO as the working electrode, a saturated calomel electrode as the reference electrode, and a Pt column electrode as the counter electrode, a fixed potential is applied; the resulting electrode is thoroughly cleaned with deionized water; and then placed in a muffle furnace for annealing to obtain CBFO / ITO. (7) The electrode obtained in step (6) is used as a template molecule of triazole thiophosphorus and a functional monomer of pyrrole to form a molecularly imprinted polymer film on the electrode surface by electrochemical polymerization; then the electrode is immersed in a mixed solution of acetic acid and methanol to elute the template molecule TAP, and a molecularly imprinted dual-electrode self-powered photoelectrochemical sensor is obtained to identify triazole thiophosphorus solution.

3. The method for preparing a dual-electrode self-powered photoelectrochemical sensor according to claim 2, characterized in that, In step (1), the amount of CuSO4·5H2O used is 2.5 g, the amount of NaOH used is 1.4 g, and the drying temperature is 60 °C. In step (2), the amount of melamine used is 0.3780 g, the amount of glutaraldehyde used is 0.1010 g, and the amount of dimethyl sulfoxide used is 10 mL.

4. The method for preparing a dual-electrode self-powered photoelectrochemical sensor according to claim 2, characterized in that, In step (3), the constant temperature furnace temperature is 180 °C, the heating time is 3 h, the pH value is 7~8, the vacuum freeze-drying time is 48 h, and the ultrasonic treatment time is 20 min.

5. The method for preparing a dual-electrode self-powered photoelectrochemical sensor according to claim 2, characterized in that, The ultrasonic cleaning time in step (4) is 1 hour; the drying temperature after drop coating is 60°C.

6. The method for preparing a dual-electrode self-powered photoelectrochemical sensor according to claim 2, characterized in that, In step (5), the HNO3 solution is 10%; the concentration of bismuth nitrate pentahydrate is 6.0 mM, the concentration of cobalt nitrate trihydrate is 4.0 mM and the concentration of ferric nitrate nonahydrate is 2.0 mM, and the pH value of the solution is 12.

7. The method for fabricating a dual-electrode self-powered photoelectrochemical sensor according to claim 2, characterized in that, In step (6), the fixed potential is 5 V, the duration is 150, the muffle furnace temperature is set to 500 °C, and the annealing time is 2 h.

8. The method for preparing a dual-electrode self-powered photoelectrochemical sensor according to claim 2, characterized in that, In step (7), the TAP solution concentration is 0.1 mM, the pyrrole concentration is 0.5 mM, the volume ratio of the acetic acid and methanol mixed solution is 2:8, and the TAP solution concentration is 0.1 nM.

9. A dual-electrode self-powered photoelectrochemical sensor obtained by the preparation method according to any one of claims 1 to 8.

10. The application of the dual-electrode self-powered photoelectrochemical sensor according to claim 9 in the field of detection, characterized in that, Includes the following steps: 1) Add 0.1 M PBS buffer solution (pH 6.0) to the electrolytic cell. 2) The dual-electrode system consisting of the MIP / CBFO / ITO electrode and the COF / CuO / ITO electrode as described in claim 1 is placed in the above-mentioned electrolytic cell. The light source is a 500 W high-brightness xenon lamp, and a photoelectric switch test is performed under no bias voltage. The photocurrent signal generated during the test is detected by an electrochemical workstation and displayed on a computer.

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