Photoelectrochemical self-powered sensor and preparation method and application thereof

Abstract

The application belongs to the technical field of photoelectrochemical detection, and particularly relates to a photoelectrochemical self-powered sensor and a preparation method and application thereof. The photoelectrochemical self-powered sensor is assembled together with a cathode platinum sheet and a single-chamber quartz electrolytic cell to construct a photoelectric self-powered sensor by taking an electrode co-modified by an aptamer and 3D CdS-dWO3.H2O nano material as a photoanode electrode. When the photoelectric self-powered sensor is used for detection of isocarbophos, high stability, high sensitivity, a wide linear range, good reproducibility, simple, rapid, efficient and specific detection can be realized.

Description

Technical Field

[0001] This invention belongs to the field of photoelectrochemical detection technology, and specifically relates to a photoelectrochemical self-powered sensor, its preparation method, and its application. Background Technology

[0002] Methamidophos is one of the most important organophosphorus pesticides, widely used to kill various leaf-eating insects and soil insects on plants such as wheat and cotton. This results in its widespread residues in the ecological environment, causing poisoning through the digestive tract, skin, and respiratory tract. It exhibits acute toxicity and is carcinogenic. Considering the high toxicity and carcinogenicity of methamidophos, establishing a simple, sensitive, rapid, and economical detection method for methamidophos is of great significance for environmental protection and human health.

[0003] The mainstream analytical methods for methamidophos residues are based on chromatography, including high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), and HPLC-MS. These instrumental methods offer significant advantages in terms of high sensitivity and accuracy, but they also suffer from drawbacks such as high instrument costs, time-consuming sample pretreatment, and the need for specialized personnel, limiting their application in on-site detection or rapid screening. Fluorescence, chemiluminescence, and colorimetric methods can also be used for methamidophos analysis; these methods are simple to operate but lack sensitivity. Therefore, there is an urgent need to develop a low-cost, simple, rapid, highly sensitive, and reproducible method to overcome these shortcomings.

[0004] Self-powered photoelectrochemical (PEC) sensors have attracted widespread attention due to their advantages of simple construction, small size, fast response speed, and low cost. Typically, a self-powered sensor consists of a photoanode and a cathode. Under illumination, the semiconductor material at the photoanode generates electrons and holes; electrons can be transferred to the cathode via an external circuit, where a reduction reaction occurs. Currently, PEC sensors are rarely used in the detection of methamidophos. Summary of the Invention

[0005] The purpose of this invention is to provide a photoelectrochemical self-powered sensor, its preparation method, and its application. Specifically, a self-powered sensor is constructed by using an electrode co-modified with aptamer and 3D CdS-dWO3·H2O nanomaterials as the photoanode electrode and Pt as the cathode. This sensor is then applied to detect methamidophos in the environment. Compared to 3D CdS monomers, the introduction of dWO3·H2O to construct a heterojunction can accelerate charge transfer, thereby effectively promoting the separation of electrons and holes and enhancing photoelectric conversion efficiency.

[0006] The method for preparing the photoelectrochemical self-powered sensor includes the following steps:

[0007] (1) The FTO electrode was ultrasonically cleaned for 30 min in acetone, ethanol and deionized water respectively. First, 3D CdS powder was added to dWO3·H2O dispersion and mixed. Then, the mixed dispersion was coated on the FTO surface, dried, and chitosan solution was added dropwise and dried. This is represented as 3D CdS-dWO3·H2O / FTO photoanode. The mass ratio of 3D CdS powder to dWO3·H2O is 2-3:2-18. Preferably, the mass ratio is 1:1-4.

[0008] Furthermore, the concentration of the dWO3·H2O dispersion is 2–18 mg / mL.

[0009] Further, the preparation method of the 3D CdS powder is as follows: CdCl2·2.5H2O is dissolved in an ethanol aqueous solution, then PMMA colloidal crystal balls are added, soaked at room temperature for 6 hours, and dried; then added to a Na2S·9H2O aqueous solution, soaked at 60℃ for 3 hours, washed, and dried; then heated in a muffle furnace at 400℃ for 3 hours to obtain 3D CdS powder; wherein, the mass ratio of CdCl2·2.5H2O to PMMA colloidal crystal balls is 1.2457:1.5.

[0010] Further, the preparation method of dWO3·H2O is as follows: Na2WO4·2H2O, citric acid monohydrate and glucose are dissolved in ultrapure water and stirred until transparent; HCl is added, and the mixture is stirred continuously for 30 minutes, then hydrothermally reacted at 120℃ for 24 hours, naturally cooled, centrifuged to collect the precipitate, washed and dried to obtain dWO3·H2O powder; wherein, the molar ratio of Na2WO4·2H2O, citric acid monohydrate and glucose is 1:1.5:1.

[0011] (2) An aptamer 1 solution was dropped onto the surface of the prepared 3D CdS-dWO3·H2O / FTO photoanode, and the sensor was incubated overnight at room temperature to obtain the photoanode electrode (apt / 3D CdS-dWO3·H2O / FTO). Then, the Pt cathode, the single-chamber quartz electrolytic cell, and the photoanode electrode apt / 3D CdS-dWO3·H2O / FTO were assembled together to construct a self-powered sensor;

[0012] The concentration of aptamer 1 solution was 3 μmol / L.

[0013] Furthermore, the nucleotide sequence of aptamer 1 is shown below:

[0014] The base sequence of aptamer 1 is CgC TgCAAg CTT TTT TgACTgACT gCAgCg.

[0015] Furthermore, the volume ratio of the 3D CdS / dWO3·H2O mixed solution, the chitosan solution, and the aptamer 1 solution is 1:1:1.

[0016] The present invention also provides the application of the above-mentioned self-powered sensor in the photoelectrochemical detection of methamidophos. The photoanode apt / 3D CdS-dWO3·H2O / FTO is incubated with methamidophos solutions of different concentrations at room temperature for 40 min, and then the electrode is rinsed with ultrapure water before being used to detect methamidophos.

[0017] The specific testing method includes the following steps:

[0018] S1. Prepare Na2SO4 solution;

[0019] S2. Prepare aqueous methamidophos with different concentrations;

[0020] A certain amount of methamidophos was accurately weighed and serially diluted with 3 μmol / L aptamer 2 solution to obtain a series of methamidophos standard solutions of different concentrations, ranging from 1.0 × 10⁻⁶. -11 g / mL~1.0×10 -6 g / mL;

[0021] The nucleotide sequence of aptamer 2 is shown below:

[0022] The base sequence of aptamer 2 is ATT CTT gAT CgC CAC ggT CTg gAAAAAgAg.

[0023] S3. Plotting the standard curve:

[0024] A series of known concentrations of aqueous methamidophos standard solutions were drop-coated onto the prepared electrode apt / 3DCdS-dWO3·H2O / FTO and air-dried at room temperature. The resulting modified electrode was labeled as ICP / apt / 3DCdS-dWO3·H2O / FTO.

[0025] Using ICP / apt / 3D CdS-dWO3·H2O / FTO as the photoanode and Pt as the cathode, a photoelectrochemical self-powered system was formed. Na2SO4 solution was used as the electrolyte, the xenon lamp source current was kept at 20A, and the horizontal distance between the light source outlet and the FTO conductive surface was kept at 15cm. The photocurrent of the circuit was tested using a two-electrode system, and a series of corresponding relationships between the concentration of methamidophos and the short-circuit current were obtained. The standard curve of methamidophos was calculated, and a linear relationship between the short-circuit current value after the addition of methamidophos and the logarithm of the concentration of methamidophos was established, and the corresponding linear regression equation was obtained.

[0026] S4. Actual sample testing:

[0027] Adaptor 2 was added to the test solution containing hydrated methamidophos and then drop-coated onto the photoanode electrode. After drying, ICP / apt / 3D CdS-dWO3·H2O / FTO was obtained. ICP / apt / 3D CdS-dWO3·H2O / FTO was used as the photoanode for photoelectrochemical testing, and Pt was used as the cathode to form a photoelectrochemical self-powered system. Na2SO4 solution was used as the electrolyte, and a xenon lamp was used as the light source. The short-circuit current of the circuit was tested using a two-electrode system. The short-circuit current value was substituted into the linear regression equation in step S3 for calculation to obtain the concentration of ICP in the test solution.

[0028] Preferably, in steps S3 and S4, the concentration of the Na2SO4 solution is 0.1M.

[0029] The sensor's detection limit for the concentration of methamidophos solution is 0.396 × 10⁻⁶. -12 g / mL.

[0030] The beneficial effects of this invention are as follows: Compared with traditional sensors, this invention has the following advantages:

[0031] (1) This invention combines 3D CdS and dWO3·H2O to form a heterojunction, which can accelerate charge transfer and effectively promote the separation of electrons and holes, thereby enhancing the photoelectric conversion efficiency. At the same time, the introduction of the aptamer enables the sensor to have a specific detection effect on methamidophos.

[0032] (2) The self-powered sensor prepared in this invention exhibits high stability, high sensitivity, wide linear range and good reproducibility when used for the detection of amine thiophosphate. It can achieve simple, fast, efficient and specific detection. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and examples.

[0034] Figure 1 This is a flowchart of the sensor fabrication and the detection of methamidophos in this invention;

[0035] Figure 2 It is the photocurrent of the 3DCdS-dWO3·H2O / FTO photoanodes with different ratios (3D CdS:dWO3·H2O) in the sensor;

[0036] Figure 3 This is a scanning electron microscope image of the 3D CdS-dWO3·H2O / FTO photoanode in the sensor;

[0037] Figure 4The photocurrent curves for the sensor using different photoanodes are: dWO3·H2O / FTO (a), 3DCdS / FTO (b), and 3D CdS-dWO3·H2O / FTO (c).

[0038] Figure 5 These are the current-time curves during the sensor construction process: 3D CdS-dWO3·H2O / FTO (a), apt / 3DCdS-dWO3·H2O / FTO (b) and ICP / apt / 3D CdS-dWO3·H2O / FTO (c);

[0039] Figure 6 These are the photocurrent curves of the sensor for different concentrations of ICP;

[0040] Figure 7 This is a standard curve of the photocurrent magnitude of the sensor for different concentrations of ICP versus the logarithm of the ICP concentration. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the embodiments.

[0042] like Figure 1 As shown, a method for preparing a photoelectrochemical self-powered sensor and its application in the detection of methamidophos is presented. A self-powered system is formed by using 3D CdS-dWO3·H2O / FTO as the photoanode and Pt as the cathode to achieve specific detection of methamidophos.

[0043] The following aptamer sequences are shown below:

[0044] The base sequence of aptamer 1 is CgC TgCAAg CTT TTT TgACTgACT gCAgCg;

[0045] The base sequence of aptamer 2 is ATT CTT gAT CgC CAC ggT CTg gAAAAAgAg;

[0046] Purchased from Sangon Biotech (Shanghai) Co., Ltd.

[0047] Example 1

[0048] A method for fabricating a photoelectrochemical self-powered sensor includes the following steps:

[0049] (1) Preparation of 3D CdS materials

[0050] Monodisperse polymethyl methacrylate (PMMA) colloidal spheres were prepared using a soap-free emulsion polymerization method. 5 wt% NaOH solution was mixed with raw material MMA at a volume ratio of 3:1 in a separatory funnel. After tightening the cap, the mixture was vigorously shaken for about 1 minute, then allowed to stand until the solution separated into layers. The upper layer consisted of MMA monomers. If the upper clear liquid was turbid, the above experiment was repeated until clear. Nitrogen gas was passed through deionized water and MMA for 10 minutes to remove oxygen. 18 mL of MMA and 180 mL of deionized water were measured and added to a three-necked flask. The oil bath was heated to 75 °C and stirred at 200 rpm for 1 hour. 0.15 g of potassium persulfate (KPS) was quickly added, and the reaction was completed after 5 hours. The PMMA colloidal spheres were separated from the prepared colloidal suspension by centrifugation at 1200 rpm for 10 minutes. The precipitate was washed three times with deionized water. The precipitate was dispersed in deionized water by ultrasonic treatment. The colloidal suspension was poured into a small beaker and then evaporated in a water bath at 80°C. The resulting PMMA colloidal crystals were then stored in a sealed glass container.

[0051] 1.2457 g of CdCl₂·2.5H₂O was dissolved in 10 mL of an ethanol-water solution (V:V:Water = 1:1). 1.5 g of PMMA colloidal spheres were soaked in the above solution at room temperature for 6 h, followed by drying at 60 °C for 2 h. The above sample was added to 10 mL of a 0.5 mol / L Na₂S·9H₂O aqueous solution and soaked at 60 °C for 3 h. The sample was washed three times with deionized water to remove excess sodium sulfide, and then dried at 60 °C for 3 h. The sample was heated in a muffle furnace at 400 °C for 3 h to obtain 3D CdS powder.

[0052] (2) Preparation of dWO3·H2O material

[0053] First, 0.5 mM Na₂WO₄·2H₂O, 0.75 mM citrate monohydrate (CA), and 0.5 mM glucose were dissolved in 15 mL of ultrapure water. The mixture was then stirred at room temperature until it became transparent. Next, 1.5 mL of 6 M HCl was added to the mixture, and the mixture was stirred for 30 minutes. Finally, the mixture was transferred to a hydrothermal reactor and kept at 120 °C for 24 hours. After natural cooling, the precipitate was collected by centrifugation and washed three times with deionized water. The precipitate was then vacuum dried at 60 °C for 12 hours to obtain dWO₃·H₂O powder.

[0054] (3) Preparation of photoanode (3D CdS-dWO3·H2O / FTO)

[0055] Dispersing 2 mg, 3 mg, 8 mg and 18 mg of dWO3·H2O in 1 mL of DMF solution yields dWO3·H2O dispersions with concentrations of 2 mg / mL, 3 mg / mL, 8 mg / mL and 18 mg / mL.

[0056] FTO electrode (area 1×2cm) 2 The samples were ultrasonically cleaned for 30 minutes each in acetone, ethanol, and deionized water.

[0057] First, 3 mg of 3D CdS powder was dispersed in 1 mL of dWO3·H2O dispersion with a concentration of 2 mg / mL. 20 μL of the mixed dispersion was then dropped onto the FTO surface and dried. Then, 20 μL of 0.1% chitosan solution was dropped and dried. This was expressed as 3D CdS:dWO3·H2O = 1.5:1.

[0058] 2 mg of 3D CdS powder was dispersed in 1 mL of dWO3·H2O dispersion with a concentration of 2 mg / mL. 20 μL of the mixed dispersion was then dropped onto the FTO surface and dried. Then, 20 μL of 0.1% chitosan solution was dropped on top and dried. This was expressed as 3D CdS:dWO3·H2O = 1:1.

[0059] 2 mg of 3D CdS powder was dispersed in 1 mL of dWO3·H2O dispersion with a concentration of 3 mg / mL. 20 μL of the mixed dispersion was then dropped onto the FTO surface and dried. Then, 20 μL of 0.1% chitosan solution was dropped on top and dried. This was expressed as 3D CdS:dWO3·H2O = 1:1.5.

[0060] The preparation of 3D CdS:dWO3·H2O = 1:4 and dWO3·H2O:3D CdS = 1:9 can be deduced similarly.

[0061] A photoelectrochemical self-powered system was constructed using 3D CdS-dWO3·H2O / FTO as the photoanode and Pt as the cathode. A 0.1M Na2SO4 solution was used as the electrolyte. The xenon lamp source current was maintained at 20A, and the horizontal distance between the light source outlet and the FTO conductive surface was kept at 15cm. The photocurrent of this circuit was measured using a two-electrode system. The test results are as follows: Figure 2 As shown.

[0062] from Figure 2 It can be seen that the photocurrent value is the largest when 3D CdS:dWO3·H2O=1:4. Therefore, the ratio of dWO3·H2O / 3D CdS / FTO of the complex with a ratio of 1:4 was selected for subsequent experiments.

[0063] Scanning electron microscope images of the dWO3·H2O / 3D CdS / FTO photoanode are shown below. Figure 3 .

[0064] (4) Detection of the fabrication of the self-powered aptamer sensor

[0065] The prepared 3D CdS-dWO3·H2O / FTO photoanode was added dropwise with 20 μL of 3 μM aptamer 1 solution, and the sensor was incubated overnight at room temperature to obtain the photoanode apt / 3D CdS-dWO3·H2O / FTO. Then, the Pt cathode, a single-chamber quartz electrolytic cell, and the photoanode apt / 3D CdS-dWO3·H2O / FTO were assembled together to construct a self-powered sensor.

[0066] Example 2

[0067] Sensors prepared from dWO3·H2O, 3D CdS, and 3D CdS-dWO3·H2O are denoted as dWO3·H2O / FTO, 3DCdS / FTO, and 3D CdS-dWO3·H2O / FTO, respectively. The photocurrent curves are shown for use as photoanodes.

[0068] The preparation steps of dWO3·H2O / FTO are as follows: Disperse the dWO3·H2O prepared in Example 1 in DMF solvent at a concentration of 2 mg / ml, drop 20 μL of the dispersion onto the FTO surface, and dry.

[0069] The preparation steps of 3D CdS / FTO are as follows: The 3D CdS prepared in Example 1 is dispersed in DMF solvent at a concentration of 2 mg / ml. 20 μL of the dispersion is dropped onto the FTO surface and dried. Then, 20 μL of 0.1% chitosan solution is dropped and dried.

[0070] The FTO electrode (with an area of ​​1×2cm) 2 The samples were ultrasonically cleaned for 30 minutes each in acetone, ethanol, and deionized water.

[0071] The preparation steps for 3D CdS-dWO3·H2O / FTO are the same as in Example 1.

[0072] Compare the photocurrent curves of dWO3·H2O, 3D CdS, and 3D CdS-dWO3·H2O as photoanodes.

[0073] Using dWO3·H2O / FTO (a), 3D CdS / FTO (b), and 3D CdS-dWO3·H2O / FTO (c) as photoanodes and Pt as cathodes, a self-powered photoelectrochemical system was constructed. A 0.1M Na2SO4 solution was used as the electrolyte. The xenon lamp source current was maintained at 20A, and the horizontal distance between the light source outlet and the FTO conductive surface was maintained at 15cm. The photocurrent of this circuit was measured using a two-electrode system. Figure 4 These are the current-time curves for different photoanodes used in the sensor.

[0074] Example 3

[0075] Compare the self-powered systems prepared with photoanodes and Pt cathodes before and after the combination of ICP and apt.

[0076] Using the 3D CdS-dWO3·H2O / FTO (a), apt / 3DCdS-dWO3·H2O / FTO (b), and ICP / apt / 3D CdS-dWO3·H2O / FTO (c) prepared in Example 1 as photoanodes and Pt as cathodes, a self-powered photoelectrochemical system was formed. A 0.1M Na2SO4 solution was used as the electrolyte. The xenon lamp source current was maintained at 20A, and the horizontal distance between the light source outlet and the FTO conductive surface was maintained at 15cm. The photocurrent of this circuit was measured using a two-electrode system. Figure 5 These are the current-time curves for different photoanodes used in the sensor.

[0077] The preparation steps of ICP / apt / 3D CdS-dWO3·H2O / FTO are as follows: Prepare a methamidophos standard solution: Weigh a certain amount of methamidophos and dissolve it in a 3 μM aptamer 2 solution, then dilute to obtain a methamidophos concentration of 1.0 × 10⁻⁶. -6 g / mL of methamidophos standard solution. Take 20 μL of methamidophos standard solution and drop it onto the apt / 3D CdS-dWO3·H2O / FTO prepared in Example 1. Let it air dry at room temperature for 40 min.

[0078] Example 4

[0079] The application of a photoelectrochemical self-powered sensor in the photoelectrochemical detection of methamidophos comprises the following steps:

[0080] (1) Following the method in Example 1, an apt / 3DCdS-dWO3·H2O / FTO photoanode was prepared by selecting 3D CdS:dWO3·H2O = 1:4. Then, the Pt cathode, a single-chamber quartz electrolytic cell, and the photoanode apt / 3DCdS-dWO3·H2O / FTO were assembled together to construct a self-powered sensor.

[0081] (2) Plotting the standard curve:

[0082] Prepare a standard solution of methamidophos: Dissolve a certain amount of methamidophos in a 3 μmol / L aptamer 2 solution, and then dilute stepwise to obtain methamidophos concentrations of 1.0 × 10⁻⁶. -11 g / mL, 1.0×10 -10 g / mL, 1.0×10 -9 g / mL, 1.0×10 -8 g / mL, 1.0×10 -7 g / mL, 1.0×10 -6Take 20 μL of a known concentration of methamidophos standard solution and drop it onto the prepared electrode apt / 3DCdS-dWO3·H2O / FTO. Let it air dry at room temperature for 40 min to obtain the modified electrode ICP / apt / 3DCdS-dWO3·H2O / FTO.

[0083] Using ICP / apt / 3D CdS-dWO3·H2O / FTO as the photoanode and Pt as the cathode, a self-powered photoelectrochemical system was constructed. A 0.1M Na2SO4 solution was used as the electrolyte. The xenon lamp source current was maintained at 20A, and the horizontal distance between the light source outlet and the FTO conductive surface was kept at 15cm. The photocurrent of this circuit was measured using a two-electrode system, yielding a series of photocurrent curves for different ICP concentrations. Figure 6 ), thereby calculating and obtaining the standard curve of methamidophos (). Figure 7 Then, the linear relationship between the logarithm of the concentration of methamidophos and the photocurrent was obtained, with a correlation coefficient (R²) of 0.99901 and a linear regression equation of I = 0.02661 - 0.01157Lg[C ICP The detection range for [(g / mL)] is 1.0 × 10⁻⁶. -11 -1.0×10 -6 g / mL, the limit of detection is 0.396×10 g / mL. -12 g / mL.

[0084] like Figure 6 As shown, the peak values ​​of the concentration curves for methamidophos from a to f are as follows: 1.0 × 10⁻⁶ -11 g / mL, 1.0×10 -10 g / mL, 1.0×10 -9 g / mL, 1.0×10 -8 g / mL, 1.0×10 -7 g / mL, 1.0×10 -6 g / mL.

[0085] (6) Detection of actual samples

[0086] Methamidophos was dissolved in 3 μmol / L aptamer 2 solution, and then diluted with a certain amount of river water and tap water after removing impurities to obtain a 1 μg / ml methamidophos solution. This solution was dropped onto apt / 3D CdS-dWO3·H2O / FTO and allowed to air dry at room temperature for 40 min to serve as an electrode for photoelectrochemical detection. The concentration of methamidophos in the sample was calculated according to the regression equation corresponding to the standard curve mentioned above, and the results are listed in Table 1.

[0087] Table 1. Results of ICP determination in water samples

[0088]

[0089] As shown in Table 1, the samples were tested in parallel three times, with a relative standard deviation of less than 5% and a recovery rate ranging from 98.0% to 105.3%. These results verify that this method can be used to detect samples in real-world applications.

[0090] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. The application of a photoelectrochemical self-powered sensor in the detection of methamidophos, characterized in that, The photoelectrochemical self-powered sensor uses an electrode modified with aptamer and 3D CdS-dWO3·H2O nanomaterials as the photoanode electrode and Pt as the cathode to construct a photoelectrochemical self-powered sensor. The method for preparing the photoanode electrode includes the following steps: (1) Add 3D CdS powder to dWO3·H2O dispersion and mix evenly to obtain 3D CdS-dWO3·H2O mixed solution, coat it on the cleaned FTO surface and dry it; then coat it with chitosan solution and dry it. (2) Coat with aptamer 1 solution, incubate at room temperature, and air dry to obtain photoanode electrode; the base sequence of aptamer 1 is CgC TgC AAg CTT TTT TgA CTg ACT gCA gCg; The application of the aforementioned photoelectrochemical self-powered sensor in the detection of methamidophos includes the following specific detection methods: Aptamer 2 was added to the test solution containing hydrated methamidophos and then drop-coated onto the photoanode electrode. After drying, ICP / apt / 3D CdS-dWO3·H2O / FTO was obtained. ICP / apt / 3D CdS-dWO3·H2O / FTO was used as the photoanode for photoelectrochemical testing, and Pt was used as the cathode to form a photoelectrochemical self-powered system. Na2SO4 solution was used as the electrolyte, and a xenon lamp was used as the light source. The short-circuit current of this circuit was tested using a two-electrode system. The short-circuit current value was substituted into the linear regression equation of the standard curve to calculate the concentration of ICP in the test solution. The base sequence of aptamer 2 is ATT CTT gAT CgC CAC ggT CTg gAA AAA gAg.

2. The application of the photoelectrochemical self-powered sensor according to claim 1 in the detection of amine thiophosphate, characterized in that, The mass ratio of the 3D CdS powder to dWO3·H2O is 2~3: 2~18; The concentration of the dWO3·H2O dispersion is 2~18 mg / mL; The volume ratio of the 3D CdS-dWO3·H2O mixed solution, chitosan solution, and aptamer S1 solution is 1:1:

1. The concentration of the aptamer 1 solution is 3 μmol / L; The concentration of the chitosan solution is 0.1 wt%.

3. The application of the photoelectrochemical self-powered sensor according to claim 1 in the detection of amine thiophosphate, characterized in that, The preparation method of the 3D CdS powder includes the following steps: dissolving CdCl2·2.5H2O in an ethanol aqueous solution, then adding PMMA colloidal crystal balls, soaking at room temperature for 6 h, and drying; adding to Na2S·9H2O aqueous solution, soaking at 60℃ for 3 h, washing, and drying; heating in a muffle furnace at 400℃ for 3 h to obtain 3D CdS powder; wherein the mass ratio of CdCl2·2.5H2O to PMMA colloidal crystal balls is 1.2457 : 1.

5.

4. The application of the photoelectrochemical self-powered sensor according to claim 1 in the detection of amine thiophosphate, characterized in that, Preparation of dWO3·H2O: Na2WO4·2H2O, citric acid monohydrate and glucose were dissolved in ultrapure water and stirred until transparent; HCl was added, and the mixture was stirred continuously for 30 minutes. The mixture was then hydrothermally reacted at 120℃ for 24 h, naturally cooled, centrifuged to collect the precipitate, washed, and dried to obtain dWO3·H2O powder; wherein the molar ratio of Na2WO4·2H2O, citric acid monohydrate and glucose was 1:1.5:

1.

5. The application of the photoelectrochemical self-powered sensor according to claim 1 in the detection of amine thiophosphate, characterized in that, The concentration of the Na2SO4 solution is 0.1M.

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