Preparation method of photoelectric self-powered sensor and application thereof in detection of microcystin-rr
By constructing a photoelectrochemical self-powered sensor using Py-HOF/AgIn5S8 nanomaterials, the problem of low detection efficiency of microcystin in existing technologies has been solved, achieving efficient, specific, and highly sensitive detection of microcystin-RR.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGZHOU UNIV
- Filing Date
- 2024-08-27
- Publication Date
- 2026-04-21
AI Technical Summary
Existing methods for detecting microcystin are characterized by high technical requirements, long processing times, expensive equipment, or low detection sensitivity. There is a need for an efficient and convenient analytical method to detect microcystin-RR.
A photoelectrochemical self-powered sensor was constructed using Py-HOF/AgIn5S8 nanomaterials. The heterojunction between Py-HOF and AgIn5S8 promotes the separation of electrons and holes, enhances photoelectric conversion efficiency, and achieves specific detection by introducing aptamers.
A rapid, simple, and specific detection of microcystin-RR with high stability, high sensitivity, and a wide linear range was achieved, with a detection limit of 1.72 × 10⁻¹⁵ mol/L.
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Figure CN119000826B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of photoelectrochemical detection technology, and specifically relates to a method for preparing a self-powered photoelectrochemical sensor and its application in the detection of microcystin-RR. Background Technology
[0002] Microcystins are among the most widely found cyanobacterial toxins in freshwater, first isolated from the cyanobacterial microcystis aeruginosa. Microcystins are cyclic peptides composed of seven amino acids, characterized by the presence of a specific Adda amino acid, a distinctive feature of cyanobacteria. The most common homologs are microcystin-LR, microcystin-RR, and microcystin-YR, due to the presence of leucine (L), arginine (R), or tyrosine (Y) at positions 2 and 4 (the letters are used to identify amino acids found in proteins). Among these, microcystin-RR is highly toxic, present in high concentrations, and may cause greater harm than other variants.
[0003] Currently, there are many methods for detecting microcystin, such as enzyme-linked immunosorbent assay (ELISA), high-performance liquid chromatography (HPLC), protein phosphatase inhibition assay (PPIA), liquid chromatography-mass spectrometry (LC-MS), and high-performance capillary electrophoresis (HPCE). These methods either have drawbacks such as high technical requirements, time-consuming, expensive equipment, or low detection sensitivity. Therefore, finding an efficient and convenient analytical method to detect the content of microcystin in the environment is of great significance.
[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 of the photoanode generates electrons and holes. Electrons can be transferred to the cathode through an external circuit, where a reduction reaction occurs.
[0005] AgIn5S8 possesses advantages such as high absorption coefficient, good biocompatibility, layered structure, and high stability; however, its carrier mobility is poor, the recombination rate of photogenerated electron-hole pairs is fast, and the charge transfer efficiency remains relatively low. The porous structure of HOF can promote the generation and transport of photogenerated electrons and ensure the effective output of photoelectric signals in photoelectric sensors. This invention constructs a photoelectrochemically self-powered sensor based on Py-HOF / AgIn5S8 nanomaterials for the detection of microcystin-RR. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing a photoelectrochemical self-powered sensor and its application in the detection of microcystin-RR. Specifically, a self-powered sensor is constructed using Py-HOF / AgIn5S8 nanomaterials as the photoanode electrode and Pt as the cathode to detect microcystin-RR in the environment. Compared with AgIn5S8 monomer, the introduction of HOF and the construction of a heterojunction can accelerate charge transfer, thereby effectively promoting the separation of electrons and holes and enhancing photoelectric conversion efficiency.
[0007] The solution adopted by this invention to solve its technical problem is:
[0008] A photoelectrochemical self-powered sensor is constructed using Py-HOF / AgIn5S8 nanomaterials as the photoanode electrode and Pt as the cathode.
[0009] A method for preparing a photoelectrochemically powered sensor for detecting microcystin includes the following steps:
[0010] (1) Preparation of photoanode
[0011] The ITO electrode was ultrasonically cleaned in acetone, ethanol, and deionized water for 30 min each. A Py-HOF dispersion was first coated onto the ITO surface and dried. Then, an AgIn5S8 dispersion was coated onto the ITO surface and dried, resulting in a Py-HOF / AgIn5S8 / ITO photoanode.
[0012] The concentration of AgIn5S8 dispersion was 6 mg / mL, and the drop volume of AgIn5S8 dispersion was 20 μL. The concentration of Py-HOF dispersion was 2 mg / mL, and the drop volume of Py-HOF dispersion was 20 μL.
[0013] The preparation of AgIn5S8 nanomaterials involved dissolving AgNO3 in anhydrous ethanol, then adding In(NO3)3⋅4H2O to form a homogeneous solution, denoted as solution A. Thioacetamide was dissolved in anhydrous ethanol, denoted as solution B. Solutions A and B were mixed under stirring to obtain a mixed solution. The mixture was heated at 180°C for 12 hours, allowed to cool naturally, centrifuged to collect the precipitate, washed, and dried to obtain AgIn5S8 nanoparticles. The molar ratio of AgNO3, In(NO3)3⋅4H2O, and thioacetamide was 1:5:20.
[0014] Preparation of Py-HOF material: 1,3,6,8-tetra(4-carboxyphenyl)pyrene was dissolved in N,N-dimethylformamide under ultrasonic conditions. Methanol was added to the above solution to obtain a mixed solution. The mixed solution was stored at room temperature for 12 h, and the precipitate was collected by centrifugation, washed, and dried to obtain Py-HOF material.
[0015] (2) Detection of the fabrication of a self-powered aptamer sensor
[0016] A microcystin-RR aptamer solution was dropped onto the surface of the prepared Py-HOF / AgIn5S8 / ITO photoanode, and the sensor was incubated overnight at room temperature. Then, the Pt cathode, a single-chamber quartz electrolytic cell, and the photoanode apta / Py-HOF / AgIn5S8 / ITO were assembled together to construct a self-powered sensor.
[0017] The concentration of the microcystin-RR aptamer solution was 2 μmol / L, and the drop volume was 20 μL.
[0018] The nucleotide sequence of the microcystin-RR aptamer is shown below:
[0019] Aptamer: 5'-CAG CTC AGA AGC TTG ATC CTA CTG CCC TTC AAT GTT CAC TCCTGT TTC CTG ATC TTT GTC GAC TCG AAG TCG TGC ATC TG-3'.
[0020] This invention also provides the application of the above-mentioned self-powered sensor in the photoelectrochemical detection of microcystin-RR. The photoanode apta / Py-HOF / AgIn5S8 / ITO is incubated with microcystin-RR solutions of different concentrations at room temperature for 20 min, then the electrode is rinsed with ultrapure water, and then used to detect microcystin-RR.
[0021] The specific testing method includes the following steps:
[0022] S1. Prepare phosphate-buffered saline (PBS) solution;
[0023] S2. Prepare microcystin-RR at different concentrations;
[0024] A precise amount of microcystin-RR was accurately weighed and serially diluted with deionized water to obtain a series of microcystin standard solutions of different concentrations, ranging from 1.0 × 10⁻⁶. -15 mol / L ~ 1.0 × 10 -9 mol / L;
[0025] S3. Plotting the standard curve:
[0026] A series of microcystin-RR standard solutions of known concentrations were drop-coated onto the prepared electrode apta / Py-HOF / AgIn5S8 / ITO and air-dried at room temperature. The resulting modified electrode was labeled MC-RR / apta / Py-HOF / AgIn5S8 / ITO.
[0027] Using MC-RR / apta / Py-HOF / AgIn5S8 / / ITO as the photoanode and Pt as the cathode, a photoelectrochemical self-powered system was formed. PBS buffer solution was used as the electrolyte, the xenon lamp source current was maintained at 20 A, and the horizontal distance between the light source outlet and the ITO conductive surface was maintained at 10 cm. The photocurrent of this circuit was tested using a two-electrode system, and a series of correlations between microcystin-RR concentration and short-circuit current were obtained. The standard curve of microcystin-RR was calculated, and a linear relationship between the short-circuit current value after the addition of microcystin-RR and the logarithm of the microcystin-RR concentration was established, obtaining the corresponding linear regression equation.
[0028] S4. Actual sample testing:
[0029] The actual sample is pretreated before testing, and then the pH value is adjusted. The calculation is performed based on the linear regression equation in step S3 above.
[0030] Preferably, in step S3, the pH of the PBS buffer solution is 7.4, the concentration is 0.1 mol / L, and the binding time between the analyte and the aptamer on the modified electrode apta / Py-HOF / AgIn5S8 / ITO is 5~40 min.
[0031] The limit of detection for the concentration of microcystin-RR solution detected by the sensor is 1.72 × 10⁻⁶. -15 mol / L.
[0032] The beneficial effects of this invention are as follows: Compared with traditional sensors, this invention has the following advantages:
[0033] This invention introduces AgIn5S8 material into Py-HOF to form a heterojunction, which accelerates charge transfer, effectively promoting the separation of electrons and holes and enhancing photoelectric conversion efficiency. Simultaneously, the introduction of the aptamer enables the sensor to specifically detect microcystin.
[0034] 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 microcystin-RR, enabling simple, rapid, efficient, and specific detection. Attached Figure Description
[0035] The present invention will be further described below with reference to the accompanying drawings and examples.
[0036] Figure 1 This is a flowchart of the sensor fabrication and the detection of microcystin-RR in this invention.
[0037] Figure 2 It is the photocurrent of the Py-HOF / AgIn5S8 / ITO photoanodes with different ratios (Py-HOF : AgIn5S8) in the sensor.
[0038] Figure 3 This is a scanning electron microscope image of the Py-HOF / AgIn5S8 / ITO photoanode in the sensor.
[0039] Figure 4 These are the photocurrent curves of the sensor using different photoanodes: HOF (a), AgIn5S8 (b), and HOF / AgIn5S8 (c).
[0040] Figure 5 These are the current-time curves during the sensor fabrication process: Py-HOF / AgIn5S8 / ITO (a), apta / Py-HOF / AgIn5S8 / ITO (b), and MC-RR / apta / Py-HOF / AgIn5S8 / ITO (c).
[0041] Figure 6 These are the photocurrent curves of the sensor for different concentrations of MC-RR.
[0042] Figure 7 This is a standard curve of the photocurrent magnitude of the sensor for different concentrations of MC-RR versus the logarithm of the MC-RR concentration. Detailed Implementation
[0043] The present invention will be further described in detail below with reference to the embodiments.
[0044] like Figure 1 As shown, a method for preparing a photoelectrochemical self-powered sensor and its application in the detection of microcystin-RR are presented. Py-HOF / AgIn5S8 / ITO is used as the photoanode and Pt is used as the cathode to form a self-powered system, thereby achieving the specific detection of microcystin-RR. Example 1
[0045] A method for fabricating a photoelectrochemical self-powered sensor includes the following steps:
[0046] (1) Preparation of AgIn5S8 nanomaterials
[0047] First, 0.2 mmol of AgNO3 was dissolved in 15 mL of anhydrous ethanol, and then 1 mmol of In(NO3)3⋅4H2O was added to form a homogeneous solution, denoted as solution A. Next, 4 mmol of thioacetamide was dissolved in 10 mL of anhydrous ethanol, denoted as solution B. The two solutions were mixed under stirring and placed in an autoclave, heated at 180°C for 12 hours, then allowed to cool naturally to room temperature, and all precipitates were collected. The precipitates were then collected by centrifugation and washed three times with deionized water.
[0048] (2) Preparation of Py-HOF materials
[0049] Under ultrasonic conditions, 0.225 mol of 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene was dissolved in 22.5 mL of N,N-dimethylformamide. Then, 90 mL of methanol was added to the above solution to obtain a mixed solution. The mixed solution was stored at room temperature for 12 h, the precipitate was collected by centrifugation, and washed three times with methanol and acetone, respectively.
[0050] (3) Preparation of photoanode
[0051] 2 mg, 4 mg, and 6 mg of AgIn5S8 were dispersed in 1 mL of DMF solution to obtain AgIn5S8 dispersions with concentrations of 2 mg / mL, 4 mg / mL, and 6 mg / mL; 2 mg, 4 mg, and 6 mg of Py-HOF were dispersed in 1 mL of DMF solution to obtain Py-HOF dispersions with concentrations of 2 mg / mL, 4 mg / mL, and 6 mg / mL.
[0052] ITO electrode (area 1 × 2 cm) 2The ITO surface was ultrasonically cleaned for 30 min each in acetone, ethanol, and deionized water. First, 20 μL of a 2 mg / mL Py-HOF dispersion was coated onto the ITO surface and dried. Then, 20 μL of a 2 mg / mL AgIn5S8 dispersion was coated onto the ITO surface and dried, representing a Py-HOF : AgIn5S8 = 1 : 1 ratio. Alternatively, 20 μL of a 2 mg / mL Py-HOF dispersion was coated onto the ITO surface and dried. Then, 20 μL of a 4 mg / mL AgIn5S8 dispersion was coated onto the ITO surface and dried, representing a Py-HOF : AgIn5S8 = 1 : 2 ratio. 20 μL of a 2 mg / mL Py-HOF dispersion was coated onto an ITO surface and dried. Then, 20 μL of a 6 mg / mL AgIn5S8 dispersion was coated onto the ITO surface and dried, resulting in a Py-HOF : AgIn5S8 = 1 : 3 ratio. The preparation of Py-HOF : AgIn5S8 = 2 : 1 and Py-HOF : AgIn5S8 = 3 : 1 ratios followed similarly.
[0053] from Figure 2 It can be seen that the photocurrent value is the largest when Py-HOF : AgIn5S8 = 1 : 3. Therefore, the Py-HOF / AgIn5S8 / ITO compound with a ratio of 1 : 3 was selected for subsequent experiments.
[0054] Scanning electron microscope images of the Py-HOF / AgIn5S8 / ITO photoanode are shown below. Figure 3 It can be seen that the introduction of AgIn5S8 into the Py-HOF material forms a heterojunction.
[0055] (4) Detection of the fabrication of the self-powered aptamer sensor
[0056] The prepared Py-HOF / AgIn5S8 / ITO photoanode was added dropwise with 20 μL of 2 μM microcystin-RR aptamer solution, and the sensor was incubated overnight at room temperature to obtain the photoanode apta / Py-HOF / AgIn5S8 / ITO. Then, the Pt cathode, a single-chamber quartz electrolytic cell, and the photoanode apta / Py-HOF / AgIn5S8 / ITO were assembled together to construct a self-powered sensor.
[0057] The aptamer sequence of the above sensor is as follows: aptamer: 5' -CAG CTC AGA AGC TTG ATC CTACTG CCC TTC AAT GTT CAC TCC TGT TTC CTG ATC TTT GTC GAC TCG AAG TCG TGC ATCTG-3'. Example 2
[0058] Compare the photocurrent curves of HOF, AgIn5S8 and HOF / AgIn5S8 as photoanodes.
[0059] The preparation steps for Py-HOF / ITO, AgIn5S8 / ITO, and HOF / AgIn5S8 / ITO are the same as in Example 1.
[0060] Py-HOF / ITO (a), AgIn5S8 / ITO (b), and Py-HOF / AgIn5S8 / ITO (c) were used as photoanodes for photoelectrochemical testing, with Pt as the cathode, forming a self-powered photoelectrochemical system. PBS buffer solution was used as the electrolyte, the xenon lamp source current was maintained at 20 A, and the horizontal distance between the light source outlet and the ITO conductive surface was maintained at 10 cm. 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. Example 3
[0061] Compare the self-powered systems prepared with photoanodes and Pt cathodes before and after the combination of MC-RR and apta.
[0062] The preparation steps for Py-HOF / AgIn5S8 / ITO, apta / Py-HOF / AgIn5S8 / ITO, and MC-RR / apta / Py-HOF / AgIn5S8 / ITO are the same as in Example 1.
[0063] Using Py-HOF / AgIn5S8 / ITO (a), apta / Py-HOF / AgIn5S8 / ITO (b), and MC-RR / apta / Py-HOF / AgIn5S8 / ITO (c) as photoanodes and Pt as cathodes, a self-powered photoelectrochemical system was constructed. PBS buffer solution was used as the electrolyte, the xenon lamp source current was maintained at 20 A, and the horizontal distance between the light source outlet and the ITO conductive surface was maintained at 10 cm. 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. Example 4
[0064] The application of a photoelectrochemical self-powered sensor in the photoelectrochemical detection of microcystin-RR comprises the following steps:
[0065] (1) Following the method in Example 1, an apta / Py-HOF / AgIn5S8 / ITO photoanode was prepared using a Py-HOF:AgIn5S8 ratio of 1:3. Then, the Pt cathode, a single-chamber quartz electrolytic cell, and the apta / Py-HOF / AgIn5S8 / ITO photoanode were assembled together to construct a self-powered sensor.
[0066] (2) Plotting the standard curve:
[0067] Prepare a microcystin-RR standard solution: Dissolve a certain amount of microcystin-RR in deionized water and dilute stepwise to obtain microcystin-RR concentrations of 1.0 × 10⁻⁶. -15 mol / L, 1.0×10 -14 mol / L, 1.0×10 -13 mol / L, 1.0×10 -12 mol / L, 1.0×10 -11 mol / L, 1.0×10 -10 mol / L, 1.0×10 -9 20 μL of a known concentration of microcystin-RR standard solution was drop-coated onto the prepared electrode apta / Py-HOF / AgIn5S8 / ITO. The binding time between microcystin-RR and the aptamer was 20 min. The electrode was then air-dried at room temperature to obtain the modified electrode MC-RR / apta / Py-HOF / AgIn5S8 / ITO.
[0068] A photoelectrochemical self-powered system was constructed using MC-RR / apta / Py-HOF / AgIn5S8 / ITO as the photoanode and Pt as the cathode. A 0.1 M PBS buffer solution (pH 7.4) was used as the electrolyte. The xenon lamp current was maintained at 20 A, and the horizontal distance between the light source outlet and the ITO conductive surface was kept at 10 cm. The photocurrent of this circuit was measured using a two-electrode system, yielding a series of photocurrent curves for different concentrations of MC-RR. Figure 6 ), thereby calculating and obtaining the standard curve of microcystin-RR ( ). Figure 7 Then, the linear relationship between the logarithmic value of microcystin-RR concentration and the photocurrent magnitude was obtained, with a correlation coefficient (R²) of 0.99005 and a linear regression equation of I = -0.83 - 0.01589log[C MC-RR The detection range of [(nM)] is 1.0 × 10⁻⁶. -15 -1.0×10 -9 mol / L, with a detection limit of 1.72 × 10⁻⁶. -15 mol / L.
[0069] like Figure 6 As shown, the peak values of the microcystin-RR concentration curve from left to right are: 1.0 × 10⁻⁶. -9 mol / L, 1.0×10 -10 mol / L, 1.0×10 -11 mol / L, 1.0×10 -12 mol / L, 1.0×10 -13 mol / L, 1.0×10 -14 mol / L, 1.0×10 -15 mol / L.
[0070] (3) Testing of actual samples
[0071] A certain amount of wastewater after impurity removal was used to prepare a microcystin-RR solution for photoelectrochemical detection. The concentration of microcystin-RR in the sample was calculated according to the regression equation corresponding to the standard curve mentioned above. The results are listed in Table 1.
[0072] Table 1. Determination results of MC-RR in water samples
[0073]
[0074] As shown in Table 1, the samples were tested in parallel three times, with a relative standard deviation of less than 5% and a spiked recovery rate ranging from 93% to 103%. This invention can be used to detect MC-RR in wastewater.
[0075] 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. A photoelectric self-powered sensor for detecting microcystin, characterized in that, A photoelectrochemical self-powered sensor was constructed by using microcystin aptamers combined with Py-HOF / AgIn5S8 nanomaterials as photoanode electrodes and Pt as cathode. The method for preparing the photoanode electrode is as follows: Py-HOF dispersion is coated onto a pre-cleaned ITO surface and dried; AgIn5S8 dispersion is then coated onto the ITO surface and dried, resulting in a Py-HOF / AgIn5S8 / ITO photoanode; a microcystin aptamer solution is added dropwise to the surface of the Py-HOF / AgIn5S8 / ITO photoanode and incubated at room temperature to obtain the final product. The preparation method of Py-HOF is as follows: under ultrasonic conditions, 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene is dissolved in N,N-dimethylformamide, methanol is added to obtain a mixed solution, the mixed solution is stored at room temperature for 12 h, the precipitate is collected by centrifugation, washed and dried to obtain Py-HOF.
2. The photoelectric self-powered sensor for detecting microcystin toxins according to claim 1, characterized in that, In Py-HOF / AgIn5S8 nanomaterials, the mass ratio of AgIn5S8 to Py-HOF is 1~3:
1.
3. The photoelectric self-powered sensor for detecting microcystin toxins according to claim 1, characterized in that, The nucleotide sequence of the microcystin aptamer is shown below: 5'-CAG CTC AGA AGC TTG ATC CTA CTG CCC TTC AATGTT CAC TCC TGT TTC CTG ATC TTT GTC GAC TCG AAG TCG TGC ATC TG-3'.
4. The method for preparing the photoelectric self-powered sensor for detecting microcystin as described in any one of claims 1-3, characterized in that, The method for preparing the photoanode electrode is as follows: (1) Coat the Py-HOF dispersion onto the pre-cleaned ITO surface and dry it; then coat the AgIn5S8 dispersion onto the ITO surface and dry it, which is represented as Py-HOF / AgIn5S8 / ITO photoanode. (2) Add microcystin (MC-RR) aptamer solution to the surface of Py-HOF / AgIn5S8 / ITO photoanode and incubate at room temperature to obtain apta / Py-HOF / AgIn5S8 / ITO photoanode.
5. The method for preparing a photoelectric self-powered sensor for detecting microcystin according to claim 4, characterized in that, Preparation of AgIn5S8 nanomaterials: AgNO3 was dissolved in anhydrous ethanol, and then In(NO3)3⋅4H2O was added to form a homogeneous solution, denoted as solution A; thioacetamide was dissolved in anhydrous ethanol, denoted as solution B; solutions A and B were mixed under stirring to obtain a mixed solution; the mixture was heated at 180℃ for 12 hours, naturally cooled, centrifuged to collect the precipitate, washed, and dried to obtain AgIn5S8 nanoparticles; wherein the molar ratio of AgNO3, In(NO3)3⋅4H2O and thioacetamide was 1:5:
20.
6. The method for preparing a photoelectric self-powered sensor for detecting microcystin according to claim 4, characterized in that, The concentration of AgIn5S8 dispersion is 2~6 mg / mL; the drop volume of AgIn5S8 dispersion is 20 μL; the concentration of Py-HOF dispersion is 2~6 mg / mL; the drop volume of Py-HOF dispersion is 20 μL.
7. The method for preparing a photoelectric self-powered sensor for detecting microcystin according to claim 4, characterized in that, The concentration of the MC-RR aptamer solution was 2 μmol / L, and the modification amount was 20 μL.
8. The application of the photoelectric self-powered sensor according to any one of claims 1-3 in the photoelectrochemical detection of microcystin-RR, characterized in that, Includes the following steps: The test solution was drop-coated onto the apta / Py-HOF / AgIn5S8 / ITO photoanode and allowed to air dry at room temperature. The resulting modified electrode was labeled MC-RR / apta / Py-HOF / AgIn5S8 / ITO. Using MC-RR / apta / Py-HOF / AgIn5S8 / ITO as the photoanode and Pt as the cathode, a self-powered photoelectrochemical system was formed. PBS buffer solution was used as the electrolyte, and a xenon lamp was used as the light source. The short-circuit current was measured using a two-electrode system. The short-circuit current value after the addition of MC-RR was substituted into the linear regression equation of the standard curve to calculate the concentration of MC-RR in the test solution.
9. The application of the photoelectric self-powered sensor according to claim 8 in the photoelectrochemical detection of microcystin-RR, characterized in that, The pH of the PBS buffer solution was 7.4 and the concentration was 0.1 mol / L. The binding time between the analyte and the aptamer on the modified electrode apta / Py-HOF / AgIn5S8 / ITO was 5–40 min.