A method for constructing an integrated organic photoelectrochemical transistor sensor for detecting pesticide isocarbophos

Abstract

The application discloses a kind of detection pesticide water amitraz integrated organic photoelectrochemical transistor sensor construction method.The application is integrated on the same fluorine-doped tin oxide conductive glass chip by laser etching technology to have the gate, source, drain three electrodes of organic photoelectrochemical transistor.In order to improve the activity and stability of grating material, the method of encapsulating Pd NPs in Cu-MOF and pyrolyzing is adopted, and Pd NPs / p-Cu-MOF is formed.Pyrolysis Cu-MOF with three-dimensional MOF structure as active carrier can load more Pd NPs, and the redox active copper metal elements contained therein will cause electron transfer between carrier and Pd NPs, so as to adjust the electronic state of metal active site and improve its catalytic performance.Schottky junction is formed between Pd NPs and p-Cu-MOF, which promotes the separation of electrons and holes.Pd NPs / p-Cu-MOF is used as photoactive gate material, and amino amitraz aptamer with carboxyl on the material is used as recognition element, so as to realize the OPECT sensing detection of ICP.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of electrochemical detection, and particularly relates to a construction method and use of an organic photoelectrochemical transistor sensor for detecting isocarbophos in agricultural products. BACKGROUND

[0002] Pesticides, as an important production material in modern agricultural production activities, can efficiently, quickly and economically prevent and control plant diseases and insect pests, and play a very important role in agricultural production and life. Although the widespread use of pesticides can prevent, control or eliminate plant diseases and insect pests, after a certain period of time, the pesticides will gradually decompose, transform into their derivatives or degradation products and remain in organisms, environment and food. Unreasonable use of pesticides makes the problem of pesticide residues particularly prominent. If the food consumed contains highly toxic or toxic pesticide residues, it will cause acute poisoning of the human body; and long-term consumption of food with excessive pesticide residues will cause the accumulation of toxins in the human body, leading to chronic poisoning and causing various physiological disorders. Isocarbophos ICP is a broad-spectrum insecticide and miticide, which has contact, stomach and ovicidal effects, and has good control effect on mites, lepidoptera and homoptera pests, and is mainly used for preventing and controlling red spider mites, cotton bollworms, rice stem borer and the like, and also has good effect on various scales. However, due to its high acute toxicity and easy accumulation in soil and water, it is of great significance to detect ICP residues in food and environmental samples. The mainstream analysis method for ICP residues is based on chromatography, including high performance liquid chromatography, gas chromatography-mass spectrometry and high performance liquid chromatography-mass spectrometry. These instrumental analysis methods have obvious advantages of high sensitivity and accuracy, but also have disadvantages such as expensive instruments, time-consuming sample pretreatment and professional detection personnel, which limit their application to on-site detection or rapid screening.

[0003] The organic photoelectrochemical transistor OPECT sensor has good sensitivity because the device is a combination of a sensor and an amplifier. It also integrates the advantages of organic electrochemical transistors OECTs, including excellent signal amplification and easy miniaturization; it is easy to realize the miniaturization of OPECT devices, thereby breaking through the performance and application bottleneck existing in the application of photoelectrochemical PEC sensing field. The properties of the gate material, including capacitance, photoactivity, electron transport rate and the like, have a great influence on the source-drain current; therefore, it is of great significance to the performance of the OPECT sensor. Metal organic frameworks MOFs have been widely studied in the field of photocatalysis due to their structural designability, high porosity and large specific surface area, and they also have the advantages required by an excellent carrier. However, most MOFs have poor water stability and conductivity, which is not conducive to their application in the field of electrochemical sensing. SUMMARY

[0004] The application aims to provide an OPECT sensor with high sensitivity, high selectivity and wide measurement range.

[0005] The adopted scheme is summarized as follows:

[0006] Cu-MOF is used as a carrier, Pd ions with high photoactivity are introduced, and then the obtained Pd NPs are highly dispersed in the porous matrix Pd / Cu-MOF of Cu-MOF; meanwhile, the problems of poor water stability and conductivity of Pd / Cu-MOF are solved by pyrolysis of Pd / Cu-MOF. After proper pyrolysis of Pd / Cu-MOF, a Pd NPs doped pyrolysis Cu-MOF composite material Pd / p-Cu-MOF rich in carbon can be obtained, and the Pd / p-Cu-MOF still has the porosity and morphology characteristics of MOF. In addition, the carbon left after pyrolysis of MOF has good electronic properties, which can not only protect the loaded Pd NPs from aggregation, but also improve the catalytic activity due to the electron transfer triggered by lone pair electrons of adjacent active metal components. The OPECT sensor is constructed on the integrated FTO subjected to laser etching by using Pd / p-Cu-MOF as a photoactive gate material and PEDOT:PSS coated FTO as a channel, and the sensitive and efficient detection of ICP residues in tomatoes is realized by using an aptamer as a recognition element.

[0007] The application is realized by the following specific technical schemes:

[0008] A construction method of an integrated organic photoelectrochemical transistor sensor for detecting pesticide isoprocarb, comprising the following steps:

[0009] Step 1, preparation of Pd / p-Cu-MOF composite material:

[0010] A Cu(NO3)2.3H2O aqueous solution and a benzenetricarboxylic acid H3BTC ethanol solution are prepared, the two solutions are fully mixed, heated in a high-pressure kettle, then slowly cooled to room temperature, centrifuged, fully washed with water and DMF, and vacuum dried to obtain a product Cu-MOF;

[0011] Then, the Cu-MOF is dispersed in a n-hexane solvent, ultrasonically until uniform, then a Pd(NO3)2 solution is slowly added, and stirring is continuously performed during the adding process; after the adding process is completed, the stirring is continuously performed, and when the stirring is stopped, a solid and a supernatant are separated, the solid is vacuum dried to obtain Pd 2+ doped Cu-MOF, then the Pd / Cu-MOF is dispersed in deionized water, ammonia borane is added, stirring is performed, the solid is collected and washed with ethanol, and after vacuum drying, Pd / p-Cu-MOF is obtained.

[0012] Step 2, etching of the conductive region of the OPECT device and preparation of the channel:

[0013] Cut the FTO into 12mm x 12mm size, and then use a laser marking machine to mark the gate and source-drain electrodes. The FTO conductive glass is pretreated, i.e. the FTO electrode is ultrasonically washed with toluene, acetone, anhydrous ethanol and deionized water, and then naturally air-dried or infrared dried.

[0014] Add PEDOT: PSS and DMSO to a light-proof PC tube, seal, place in a water bath and stir. Use a film applicator to spin-coat a PEDOT: PSS layer on the channel of the FTO. After film formation, the FTO is heated in an oil bath in a pure nitrogen environment.

[0015] Step 3, construction of the gate in the OPECT sensor:

[0016] Dissolve the Pd / p-Cu-MOF prepared in step 1 in ethanol to prepare a Pd / p-Cu-MOF dispersion;

[0017] Modify the Pd / p-Cu-MOF dispersion to the gate region of the FTO treated in step 2, and dry; then modify EDC-NHS to the surface of the Pd / p-Cu-MOF / FTO, incubate, then rinse with PBS; continue to add an amino-containing ICP aptamer solution to the region, incubate, then rinse with PBS again; continue to modify ethanolamine MEA to the region, block unbound carboxyl groups, rinse with a PBS buffer solution, and dry at room temperature. Finally, an integrated aptamer-modified Pd / p-Cu-MOF / FTO electrode, i.e. an integrated organic photoelectrochemical transistor sensor, is obtained.

[0018] In step 1, the amount ratio of copper nitrate, ultrapure water, trimesic acid and ethanol is 0.04-0.08 mmol: 12 mL: 0.02-0.03 mmol: 12 mL;

[0019] The heating temperature in the autoclave is 200-400℃, and the time is 12h.

[0020] In step 1, the amount ratio of Cu-MOF, n-hexane, Pd(NO3)2 and ammonia borane is 400 mg: 40 mL: 1-5 mL: 20 mg, wherein the concentration of the Pd(NO3)2 solution is 50 mg·mL -1 .

[0021] The calcination temperature in the muffle furnace is 300℃, and the time is 12h.

[0022] In step 2, the radius of the gate is 2.5mm, and the length and width of the source-drain electrodes are 0.12mm and 6mm, respectively.

[0023] The ratio of PEDOT:PSS and DMSO is 950 μL:50 μL;

[0024] The temperature of the water bath is 10℃, and the stirring time is 4h;

[0025] When spin coating, the rotation rate of the spin coater is 1000 rpm-3000 rpm, and the time is 6s-40s;

[0026] After spin coating, the oil bath heating condition is: heating to 130℃ for 20 min and then heating to 150℃ for 1h.

[0027] In step 3, the concentration of the Pd / p-Cu-MOF dispersion liquid is 2-5 mg / mL, and the modification amount is 10-20 μL;

[0028] In EDC-NHS, the concentration of EDC is 10 mg / mL, the concentration of NHS is 10 mg / mL, and the amount used is 10-20 μL;

[0029] The concentration of the amino-containing ICP aptamer solution is 1-5 μM, and the dropwise addition amount is 20 μL;

[0030] The concentration of ethanolamine MEA is 1 mol / L, and the modification amount is 10-20 μL;

[0031] The incubation temperature is 25-26℃, and the time is 0.5h;

[0032] The sequence of the amino-containing ICP aptamer is:

[0033] 5'-NH2-AGCT2GCTGCAGCGAT2CT2GATCGC2ACAGAGCT-3';

[0034] The use of the OPECT integrated organic photoelectrochemical crystal sensor prepared in the application for detecting ICP is as follows:

[0035] Different concentrations of ICP dispersion liquid are dropped on the gate region of the prepared OPECT device, incubated at room temperature for 20 min, and then washed with PBS; the circular gate region and the following part of the above-mentioned OPECT integrated sensor are immersed in a pool containing PBS solution, the light source is turned on, the electrochemical workstation is connected, the I-t Curve is used for real-time monitoring, when the baseline of the I-t curve is stable, the electrode is irradiated with light, the source and drain current change is observed and saved.

[0036] In step 4, the concentration of the ICP dispersion liquid is 0.1 ng·L -1 ~ 10 μg·L -1, the modification amount is 10-20 muL, and the incubation condition is 37 DEG C for 20 minutes.

[0037] The model of the workstation is CHI1010C, and the light source is a xenon lamp parallel light source system instrument, and the parameter setting is that the source-drain voltage is -0V, and the gate voltage is 0V.

[0038] The present application has the beneficial effects that:

[0039] The present application integrates the traditional three-electrode system by laser etching technology, that is, integrates the gate, source and drain electrodes of OPECT on the same fluorine-doped tin oxide conductive glass FTO chip, synthesizes Pd nanoparticle loaded pyrolysis Cu-MOF as a light gate, and establishes an OPECT detection method for ICP in a tomato sample, and the characteristics and advantages are as follows:

[0040] (1) The Pd / p-Cu-MOF nanocomposite prepared in the present application is used as a photoactive gate material to construct an OPECT sensor, and the photocurrent signal of the nanocomposite is greatly enhanced relative to the monomer, and the stability is improved. This may be because, in addition to the reasons such as the increase of conductivity after pyrolysis, the increase of electron migration rate, the widening of visible light absorption range, and the richer defects in the framework structure, the formation of Schottky junction between Pd NPs and p-Cu-MOF also reduces the electron-hole recombination rate.

[0041] (2) The present application constructs an OPECT aptamer sensor for ICP detection by virtue of the excellent photoelectric performance of Pd / p-Cu-MOF nanocomposite, specific aptamer and signal amplification PEDOT:PSS channel. The OPECT sensor shows a wider linear range 1.0x10 -10 ~1.0x10 -3 g·L -1 and a lower detection limit 3.3x10 -11 g·L -1 .

[0042] (3) In addition, the constructed OPECT aptamer sensor is used to detect ICP in a tomato sample, and satisfactory results are obtained. This work not only demonstrates the potential attraction of Pd / p-Cu-MOF nanocomposite with Schottky junction in OPECT related applications, but also constructs a novel integrated OPECT sensing platform for food detection, biomedical and environmental monitoring and other fields.

[0043] (4) The traditional three-electrode system is integrated on the same FTO conductive glass chip by laser etching technology, and such OPECT sensor is easy to miniaturize and portable, and can be applied to ICP efficient and rapid on-site detection with integrated electrodes. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 Infrared spectrum A and XRD spectrum B of Cu-MOF of Example 1 and its modified products;

[0045] Figure 2 SEM images of (A) Pd / Cu-MOF and (B) Pd / p-Cu-MOF of Example 1, TEM images of (C) Pd / Cu-MOF and (D) Pd / p-Cu-MOF;

[0046] Figure 3 Photocurrent response A and impedance B of Cu-MOF of Example 1 and its modified products;

[0047] Figure 4 Thermogravimetric analysis A and electron spin resonance spectrum B of Cu-MOF and Pd / Cu-MOF of Example 1;

[0048] Figure 5 Charge transfer path and detection mechanism of Pd / p-Cu-MOF functional composite material of Example 1;

[0049] Figure 6 Photocurrent response A of PEC aptamer sensor and OPECT aptamer sensor constructed in Example 1 to different concentrations of ICP, as well as channel current response C, and corresponding linear relationship B and D. DETAILED DESCRIPTION

[0050] The present application will be described in detail below in conjunction with examples, but the present application is not limited to these examples.

[0051] Example 1:

[0052] (1) Preparation of Cu-MOF and its nanocomposite

[0053] Prepare 3.6mM Cu(NO3)2·3H2O aqueous solution and 2.0mM H3BTC ethanol solution. Then mix 12mL of the two solutions well, put them into an autoclave and heat at 200℃ for 12h, and then slowly cool to room temperature. Centrifuge the product to obtain Cu-MOF, wash with water and DMF, and dry at 80℃ under vacuum for 24h for standby.

[0054] Disperse 400mg Cu-MOF in 40mL n-hexane solvent, and ultrasonic for about 20min until uniform. After stirring for 10min, slowly add 1mL of hydrophilic Pd(NO3)2 solution (50mg·mL -1), with more than 20 minutes, and continuously stirring during the period. Then, the obtained mixture was continuously stirred for 3h. When the stirring was stopped, the solid precipitated to the bottom of the bottle and the supernatant were separated. The synthesized solid sample was further dried under vacuum at 85℃ for 12h to obtain Pd / Cu-MOF. 2+ Doped CuMOF.

[0055] The above synthesized solid was suspended and dispersed in 40mL of deionized water, 20mg of ammonia borane was added, stirred for 5h, the solid was collected and washed with ethanol for 3 times, and dried in a vacuum oven at 60℃ to obtain Pd / Cu-MOF.

[0056] The obtained sample was calcined in a muffle furnace at 300℃ for 12h to obtain Pd / p-Cu-MOF.

[0057] Figure 1 The infrared spectrum (A) and X-ray diffraction pattern (B) of CuMOF and its composite material are shown, which proves the successful synthesis of CuMOF and its composite material.

[0058] Figure 2 The electron micrograph of Pd / Cu-MOF and its pyrolysis product is shown. As can be seen from the figure, the Pd nanoparticles are uniformly distributed inside the Cu-MOF, and the pyrolysis does not make its morphology collapse.

[0059] And as shown in Figure 3 , the doping and pyrolysis of Pd nanoparticles can both improve its photoelectric signal and reduce its impedance.

[0060] As shown in Figure 4 , 300℃ does not cause the framework of Cu-MOF to collapse; and there are a large number of oxygen vacancies in Pd / Cu-MOF after pyrolysis (as shown in Figure 4 B).

[0061] (2) Preparation of OPECT device channel

[0062] Cut the FTO into 12mm x 12mm size, and then etch a gate with a radius of 2.5mm, source and drain electrodes with a length and width of 0.12mm and 6mm respectively, and the FTO conductive glass is pretreated as follows: ultrasonic washing the FTO electrode with toluene, acetone, anhydrous ethanol, deionized water for 15min, and naturally air-drying or infrared drying. Add 950μL of PEDOT:PSS and 50μL of DMSO to a light-proof PC tube, seal, and place in a 10℃ water bath, stir for 4h. Spin coat the PEDOT:PSS layer on the homogenizer, at a speed of 6s, 1000rpm; 40s, 3000rpm. The coated device is heated in a pure nitrogen environment, and the temperature is raised to 130℃ and heated for 20min; then the temperature is raised to 150℃ and heated for 1h.

[0063] (3) Construction of OPECT aptamer sensor for detecting ICP

[0064] Sensor construction as shown in Figure 5 , 6 mg Pd / p-Cu-MOF was dissolved in 3 mL of ethanol to prepare a 2 mg·mL -1 dispersion of Pd / p-Cu-MOF. 20 μL of the dispersion of Pd / p-Cu-MOF was pipetted onto the FTO surface with a fixed area of 9 mm 2 , and dried, denoted as Pd / p-Cu-MOF / FTO. Further, 10 μL of EDC with a concentration of 10 mg·mL -1 and 10 μL of NHS with a concentration of 10 mg·mL -1 were modified onto the Pd / p-Cu-MOF / FTO surface, and incubated at 26°C for 0.5 h, and then rinsed with PBS. Next, 20 μL of the amino-functionalized ICP aptamer solution (4 μM) was dropped onto the FTO electrode, and left at room temperature for 2 h. Further, 10 μL of ethanolamine (MEA) with a concentration of 1 mol·L -1 was modified on the electrode surface, and incubated at 25°C for 0.5 h, to block the unbound carboxyl groups, rinsed with PBS buffer solution, and dried at room temperature. Finally, an integrated aptamer-modified Pd / p-Cu-MOF / FTO electrode was obtained.

[0065] (4) OPECT signal detection

[0066] The electrochemical experiment was performed on a workstation with a model number of CHI1010C, and the light source was a xenon lamp parallel light source system instrument. The modified electrode was used as the gate electrode of OPECT, and was immersed in a pool containing PBS solution together with the source and drain of the OPECT device, the light source was turned on, the electrochemical workstation was turned on, and the I-t curve was used for real-time monitoring. When the baseline of the I-t curve was stable, the electrode was irradiated with light, and the current change of the source and drain was observed. The parameter settings were as follows: the source-drain voltage was -0.2 V, and the gate voltage was 0 V. As shown in Figure 6 , the photoelectric current response graph A and the OPECT channel current response graph C of the PEC aptamer sensor constructed from Figure 6 showed that for the detection of ICP, the sensitivity of OPECT was greatly improved relative to PEC, and had a wider linear range.

[0067] Example 2:

[0068] (1) Preparation of Cu-MOF and its nanocomposite

[0069] A 2.4 mM aqueous solution of Cu(NO3)2-3H2O and a 2.0 mM solution of H3BTC in ethanol were prepared. Then 12 mL of both solutions were mixed thoroughly and placed in an autoclave for 12 h of heating, followed by slow cooling to room temperature. The product was centrifuged to obtain Cu-MOF, which was washed thoroughly with water and DMF, and dried under vacuum at 80 °C for 24 h for storage.

[0070] A 400 mg sample of Cu-MOF was dispersed in 40 mL of n-hexane solvent and sonicated for about 20 min until uniform. After stirring for 10 min, 3 mL of a hydrophilic Pd(NO3)2solution (50 mg mL -1 ) was slowly added using a syringe pump over 20 min or more, with continuous vigorous stirring. Subsequently, the resulting mixture was continuously stirred for 3 h. When stirring was stopped, the solid precipitated to the bottom of the bottle was separated from the supernatant. The synthesized solid sample was further dried under vacuum at 85 °C for 12 h to obtain Pd 2+ doped CuMOF.

[0071] The above synthesized solid was suspended and dispersed in 40 mL of deionized water, 20 mg of ammonia borane was added, stirred for 5 h, the solid was collected and washed with ethanol for 3 times, and dried in a vacuum drying oven at 60 °C to obtain Pd / Cu-MOF.

[0072] The obtained sample was calcined in a muffle furnace at 300 °C for 12 h to obtain Pd / p-Cu-MOF.

[0073] Steps (2), (3), (4) are the same as steps (2), (3), (4) of Example 1.

[0074] Example 3:

[0075] (1) Preparation of Cu-MOF and its nanocomposites

[0076] A 2.4 mM aqueous solution of Cu(NO3)2-3H2O and a 2.0 mM solution of H3BTC in ethanol were prepared. Then 12 mL of both solutions were mixed thoroughly and placed in an autoclave for 12 h of heating, followed by slow cooling to room temperature. The product was centrifuged to obtain Cu-MOF, which was washed thoroughly with water and DMF, and dried under vacuum at 80 °C for 24 h for storage.

[0077] A 400 mg sample of Cu-MOF was dispersed in 40 mL of n-hexane solvent and sonicated for about 20 min until uniform. After stirring for 10 min, 3 mL of a hydrophilic Pd(NO3)2solution (50 mg mL -1 ) was slowly added using a syringe pump over 20 min or more, with continuous vigorous stirring. Subsequently, the resulting mixture was continuously stirred for 3 h. When stirring was stopped, the solid precipitated to the bottom of the bottle was separated from the supernatant. The synthesized solid sample was further dried under vacuum at 85 °C for 12 h to obtain Pd2+ doped CuMOF.

[0078] The above synthesized solid was suspended and dispersed in 40 mL of deionized water, 20 mg of ammonia borane was added, stirred for 5 h, the solid was collected and washed with ethanol for 3 times, dried in a vacuum drying oven at 60 °C to obtain Pd / Cu-MOF.

[0079] The obtained sample was calcined in a muffle furnace at 300 °C for 12 h to obtain Pd / p-Cu-MOF.

[0080] Steps (2), (3), (4) are the same as steps (2), (3), (4) of Example 1.

Claims

1. A method for constructing an integrated organic photoelectrochemical transistor sensor for detecting the pesticide isocarbophos, characterized by, Comprising the following steps: Step 1, preparation of Pd / p-Cu-MOF composite material: Prepare Cu(NO3)2·3H2O aqueous solution and H3BTC ethanol solution, mix the two solutions well, put them into an autoclave, heat, then slowly cool to room temperature, centrifuge, wash with water and DMF, and vacuum dry to obtain the product Cu-MOF; Then the Cu-MOF was dispersed in n-hexane solvent, and after ultrasonic treatment to be uniform, Pd(NO3)2 solution was slowly added, and the stirring was continuously performed during the addition. After the dropwise addition was completed, the stirring was continuously performed until the stirring was stopped. The solid and supernatant were separated, and the solid was vacuum dried to obtain Pd 2+ The doped Cu-MOF was then dispersed in deionized water, and ammonia borane was added. After stirring, the solid was collected and washed with ethanol. After vacuum drying, Pd / Cu-MOF was obtained. Then, the Pd / Cu-MOF was continuously placed in a muffle furnace for calcination to obtain Pd / p-Cu-MOF. Step 2, etching of conductive region of OPECT device and preparation of channel: First, cut the FTO, then use a laser marking machine to mark the gate and source-drain electrodes, and pretreat the FTO conductive glass, that is, ultrasonically wash the FTO electrode with toluene, acetone, anhydrous ethanol and deionized water respectively, and then air dry or infrared dry; Add PEDOT:PSS and DMSO into a light-proof PC tube, seal, place in a water bath and stir; use a spin coater to spin coat a PEDOT:PSS layer on the channel of the FTO; after spinning, heat the FTO in an oil bath in a pure nitrogen environment; Step 3, construction of gate in OPECT sensor: Dissolve the Pd / p-Cu-MOF prepared in step 1 in ethanol to prepare a Pd / p-Cu-MOF dispersion; Take the Pd / p-Cu-MOF dispersion to modify the gate region of the FTO treated in step 2, and dry, denoted as Pd / p-Cu-MOF / FTO; then modify EDC-NHS to the surface of Pd / p-Cu-MOF / FTO, incubate, then rinse with PBS; continue to add an amino-containing isocarbophos (ICP) aptamer solution to the region, incubate, then rinse with PBS again; continue to modify ethanolamine (MEA) in the region, block unbound carboxyl groups, rinse with PBS buffer solution, and dry at room temperature to obtain an integrated aptamer-modified Pd / p-Cu-MOF / FTO electrode, that is, an integrated organic photoelectrochemical transistor sensor.

2. The construction method of claim 1, characterized in that, In step 1, the amount ratio of copper nitrate, ultrapure water, benzene-1, 3, 5-tricarboxylic acid and ethanol is 0.04-0.08 mmol:12 mL:0.02-0.03 mmol:12 mL; the heating temperature in the autoclave is 200-400℃, and the time is 12h.

3. The construction method of claim 1, wherein In step 1, the ratio of the amount of Cu-MOF, n-hexane, Pd(NO3)2 and ammonia borane is 400 mg: 40 mL: 1-5 mL: 20 mg, wherein the concentration of Pd(NO3)2 solution is 50 mg·mL -1 ; the temperature of calcination in the muffle furnace is 300℃, and the time is 12 h.

4. The construction of claim 1, wherein In step 2, the size of the FTO is 12mm×12mm, the radius of the gate is 2.5mm, and the length and width of the source-drain electrodes are 0.12mm and 6mm respectively.

5. The construction of claim 1, wherein In step 2, The amount ratio of PEDOT:PSS and DMSO is 950μL:50μL; The temperature of the water bath is 10℃, and the stirring time is 4h; When spinning, the speed of the spin coater is 1000rpm-3000rpm, and the time is 6s-40s; The oil bath heating is: heating to 130℃ for 20min, then heating to 150℃ for 1h.

6. The construction of claim 1, wherein In step 3, The concentration of the Pd / p-Cu-MOF dispersion is 2-5mg / mL, and the modification amount is 10-20μL; In EDC-NHS, the concentration of EDC is 10mg / mL, the concentration of NHS is 10mg / mL, and the amount used is 10-20μL; The concentration of the amino-containing ICP aptamer solution is 1-5μM, and the dropwise addition amount is 20μL; The concentration of ethanolamine (MEA) is 1 mol / L, and the modification amount is 10-20 μL The temperature of incubation is 25-26℃, and the time is 0.5 h.

7. The construction of claim 1, wherein In step 3, the amino-containing ICP aptamer sequence is: 5'-NH2-AGCT2GCTGCAGCGAT2CT2GATCGC2ACAGAGCT-3'.

8. An integrated organic photoelectrochemical transistor sensor, characterized in that The construction method is obtained by using any one of claims 1-7.

9. Use of the integrated organic photoelectrochemical transistor sensor of claim 8 for detecting isochlorothion (ICP).

10. The use according to claim 9, characterized in that, The specific steps are as follows: The concentration is 0.1 ng·L -1 ~10μg·L -1 10-20 μL of ICP dispersion was dropped onto the gate region of the integrated organic photoelectrochemical transistor sensor and incubated at room temperature (37°C) for 20 min, then rinsed with PBS. The circular gate region and below of the sensor were immersed in a pool containing PBS solution. The light source was turned on and the electrochemical workstation was connected. The It Curve was used for real-time monitoring. When the baseline of the It Curve stabilized, the electrodes were illuminated, and the changes in source and drain currents were observed and recorded.

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