Preparation method of organic photoelectrochemical transistor sensing platform for detecting acetamiprid

Abstract

A preparation method of an organic photoelectrochemical transistor sensing platform for detecting acetamiprid is characterized in that a detection platform with high sensitivity and selectivity is constructed, and the organic photoelectrochemical transistor sensing platform with high sensitivity is constructed by innovatively combining iron ion doped polydopamine nanospheres and a ZnIn2S4 photoelectric material. And an effective solution is provided for rapid detection of acetamiprid.

Description

Technical Field

[0001] This invention belongs to the field of organic photoelectrochemical transistor sensing technology, specifically relating to an organic photoelectrochemical transistor sensing platform based on iron ion-doped polydopamine nanospheres and ZnIn2S4 photoelectric material for high-sensitivity detection of acetamiprid. This technology combines materials science, chemistry, and electronic engineering to achieve rapid, sensitive, and specific pesticide residue detection. Background Technology

[0002] The use of pesticides is of great importance in agricultural production, but their residues pose a potential threat to the environment and human health. Acetamiprid, as a widely used pesticide, is characterized by high efficiency and low toxicity, but it may also have negative impacts on ecosystems and human health. Therefore, rapid, sensitive and specific detection of its residues is of great significance.

[0003] Organic photoelectrochemical transistors (OPTs) are novel detection devices combining photosensitive materials and organic semiconductor materials, exhibiting significantly higher sensitivity and response speeds than traditional photoelectrochemical sensors. However, further improving their detection sensitivity and selectivity, particularly for the specific detection of acetamiprid, remains a challenging research topic. This invention proposes an OPT sensing platform based on iron-doped polydopamine nanospheres and ZnIn2S4 photoelectric material. By optimizing the material preparation process and sensor structure design, the detection sensitivity and selectivity are significantly improved, providing an efficient and reliable solution for the rapid detection of acetamiprid. Summary of the Invention

[0004] One of the objectives of this invention is to utilize the organic photoelectrochemical transistor sensing platform of this invention, which employs ZnIn2S4 as a photoactive material. This material provides excellent photocurrent response and a large number of active sites, thereby promoting the loading of capture antibodies.

[0005] The second objective of this invention is to improve the separation efficiency of photogenerated electron-hole pairs through the optimized preparation process of ZnIn2S4 material, thereby solving the problem of short carrier lifetime caused by carrier recombination;

[0006] The third objective of this invention is to construct an iron-doped polydopamine nanosphere to introduce an iron-doped polydopamine nanosphere into the sensing platform, thereby achieving a signal amplification effect. Furthermore, by utilizing its own specific binding ability, it works synergistically with ZnIn2S4 material to further enhance detection sensitivity.

[0007] The fourth objective of this invention is that the sensing platform based on organic photoelectrochemical transistors exhibits good selectivity and stability for acetamiprid, and has high sensitivity detection performance for the target analyte, thus meeting the needs of practical applications.

[0008] The technical solution of this invention is as follows: 1. A method for preparing an organic photoelectrochemical transistor sensing platform for detecting acetamiprid, characterized by comprising the following steps: (1) Preparation of iron-doped polydopamine nanosphere composite material linked to a second antibody Weigh 65-75 mg of dopamine hydrochloride and 0.05-0.1 g of ferric chloride, dissolve them in 50-60 mL of deionized water, and then sonicate for 12-15 minutes. Transfer the treated solution to a constant temperature stirrer and stir continuously at 30-40℃ for 2-3 hours. After the reaction is complete, wash the solution with ethanol and deionized water by centrifugation until neutral, and finally obtain the product by freeze drying. The dried nanomaterials were dispersed in 8 mL of pH 7.4 phosphate buffer, and 5-6 μg / mL of acetamiprid secondary antibody was added. The mixture was shaken at room temperature for 0.8 hours, and then 1-1.5% bovine serum albumin solution was slowly added to block the non-specific binding sites on the surface of the material. After vigorous shaking for another 0.5 hours, the mixture was centrifuged and washed. Finally, the product was dispersed in 2 mL of pH 4 phosphate buffer and stored at 4°C for later use. (2) Fabrication of organic photoelectrochemical transistor sensing platform 1) Cut indium tin oxide conductive glass to the required size and pre-treat it to prepare ITO electrodes; 2) Add 80-90 μL of a ZnIn2S4 solution with a concentration of 8-10 mg / mL to the surface of the ITO electrode, and then place it in a muffle furnace and calcine it at 80-150℃ for 1-2 hours to enhance the bonding strength between the photoelectric material and the electrode. 3) Add 3-4 μL of 0.8-1 mol / L mercaptoacetic acid solution to the ZnIn2S4 electrode and incubate for 0.5-0.8 hours; then add 2-3 μL of 8-10 μg / mL acetamiprid primary antibody solution, 1% bovine serum albumin solution and different concentrations of acetamiprid solution in sequence, and let stand at 4℃ for 40 minutes to achieve fixation and modification; 4) 6-8 μL of the prepared second antibody-modified polydopamine nanosphere solution was left to stand at 37°C for 1 hour to allow it to specifically bind to acetamiprid and be fixed on the electrode surface modified with photoelectric material. 5) Place the photoelectric modified electrode and organic transistor under the workstation for signal testing; 2. The method for preparing an organic photoelectrochemical transistor sensing platform for detecting acetamiprid as described in claim 1, characterized in that the iron-doped polydopamine nanospheres are prepared by the following steps: Weigh 65-75 mg of dopamine hydrochloride and 0.05-0.1 g of ferric chloride, dissolve them in 50-60 mL of deionized water, and then sonicate for 12-15 minutes. Transfer the treated solution to a constant temperature stirrer and stir continuously at 30-40℃ for 2-3 hours. After the reaction is complete, wash the solution with ethanol and deionized water by centrifugation until neutral, and finally obtain the product by freeze drying. The dried nanomaterials were dispersed in 8 mL of pH 7.4 phosphate buffer, and 5-6 μg / mL of acetamiprid secondary antibody was added. The mixture was shaken at room temperature for 0.8 hours, and then 1-1.5% bovine serum albumin solution was slowly added to block the non-specific binding sites on the surface of the material. After vigorous shaking for another 0.5 hours, the mixture was centrifuged and washed. Finally, the product was dispersed in 2 mL of pH 4 phosphate buffer and stored at 4°C for later use. 3. The method for preparing an organic photoelectrochemical transistor sensing platform for detecting acetamiprid as described in claim 1, characterized in that the photoelectrochemical material ZnIn2S4 is prepared by the following steps: Preparation of ZnIn2S4 material: First, 0.5-0.6 g of zinc nitrate and 0.1-0.2 g of indium nitrate were dissolved in 10-15 mL of deionized water and stirred under magnetic stirring for 20-25 minutes. Then, copper nitrate and indium nitrate solutions were mixed and stirred thoroughly. The mixed solution was transferred to a reaction vessel and subjected to hydrothermal reaction at 80-100℃ for 8-10 hours. After the reaction was completed, the mixture was cooled to room temperature, the precipitate was collected by centrifugation, and washed several times with deionized water. The washed precipitate was dried at 50-60℃ for 8 hours, and then calcined at 150-180℃ for 40-60 minutes. Finally, after cooling to room temperature, the solid powder was ground to obtain ZnIn2S4 nanomaterials. 4. The method for preparing an organic photoelectrochemical transistor sensing platform for detecting acetamiprid as described in claim 1, characterized in that the organic photoelectrochemical transistor is prepared by the following steps: The source and drain electrodes were integrated with an organic semiconductor layer to construct a conductive channel, and a photosensitive gate electrode was used as the control terminal. The specific fabrication steps are as follows: First, a glass substrate with a size of 15 mm × 18 mm was ultrasonically cleaned with acetone, ethanol and ultrapure water in sequence, followed by drying. After fixing the mask on the substrate, a 12 nm thick chromium layer and an 80 nm thick gold layer were sequentially prepared by magnetron sputtering to form the source and drain electrodes. The length and width of the conductive channel between the two electrodes were set to 0.4-0.5 mm and 8-10 mm, respectively. After the prepared template was treated with a plasma cleaning device for 4-5 minutes, a CdS-loaded PEDOT:PSS solution was coated on the surface of the conductive channel using a spin coating device to form a polymer coating. To improve the bonding strength of the coating on the glass substrate, the device was placed in a nitrogen environment and annealed at 150 °C for 1 hour.

[0009] Beneficial results of the present invention (1) The organic photoelectrochemical transistor sensing platform of the present invention uses ZnIn2S4 as a photoactive material, which provides excellent photocurrent response and a large number of active sites, promoting the loading of capture antibodies. (2) By optimizing the preparation process of ZnIn2S4 material, the separation efficiency of photogenerated electron-hole pairs was improved, and the problem of short carrier lifetime caused by carrier recombination was solved. (3) The iron-doped polydopamine nanospheres introduced into the sensing platform realize the signal amplification effect, and utilize their own specific binding ability to synergize with ZnIn2S4 material to further enhance the detection sensitivity. (4) The sensing platform based on organic photoelectrochemical transistors has good selectivity and stability for acetamiprid and high sensitivity detection performance for the target, which meets the needs of practical applications. Detailed Implementation Plan Example 1

[0010] (1) Preparation of iron-doped polydopamine nanosphere composite material linked to a second antibody Weigh 75 mg of dopamine hydrochloride and 0.05 g of ferric chloride, dissolve them in 50 mL of deionized water, and then sonicate for 13 minutes. Transfer the treated solution to a constant temperature stirrer and stir continuously at 35°C for 2 hours. After the reaction is complete, wash with ethanol and deionized water by centrifugation until neutral, and finally obtain the product by freeze drying. The dried nanomaterials were dispersed in 8 mL of pH 7.4 phosphate buffer, and 5 μg / mL acetamiprid secondary antibody was added. The mixture was shaken at room temperature for 0.8 hours, and then 1% bovine serum albumin solution was slowly added to block the non-specific binding sites on the surface of the material. After vigorous shaking for 0.5 hours, the mixture was centrifuged and washed. Finally, the product was dispersed in 2 mL of pH 4 phosphate buffer and stored at 4°C for later use. (2) Fabrication of organic photoelectrochemical transistor sensing platform 1) Cut indium tin oxide conductive glass to the required size and pre-treat it to prepare ITO electrodes; 2) 80 μL of a ZnIn2S4 solution with a concentration of 8 mg / mL was added dropwise to the surface of the ITO electrode, and then placed in a muffle furnace and calcined at 80°C for 1 hour to enhance the bonding strength between the photoelectric material and the electrode. 3) Add 3 μL of 0.8 mol / L mercaptoacetic acid solution to the ZnIn2S4 electrode and incubate for 0.5 hours; then add 2 μL of 8 μg / mL acetamiprid primary antibody solution, 1% bovine serum albumin solution and different concentrations of acetamiprid solution in sequence, and let stand at 4℃ for 40 minutes to achieve fixation and modification; 4) 7 μL of the prepared second antibody-modified polydopamine nanosphere solution was left to stand at 37°C for 1 hour to allow it to specifically bind to acetamiprid and be fixed on the electrode surface modified with photoelectric material. 5) Place the photoelectric modified electrode and organic transistor under the workstation for signal testing; 2. The iron-doped polydopamine nanospheres are prepared by the following steps: Weigh 70 mg of dopamine hydrochloride and 0.1 g of ferric chloride, dissolve them in 60 mL of deionized water, and then sonicate for 15 minutes. Transfer the treated solution to a constant temperature stirrer and stir continuously at 40°C for 2 hours. After the reaction is complete, wash with ethanol and deionized water by centrifugation until neutral, and finally obtain the product by freeze drying. The dried nanomaterials were dispersed in 8 mL of pH 7.4 phosphate buffer, and 5 μg / mL acetamiprid secondary antibody was added. The mixture was shaken at room temperature for 0.8 hours, and then 1% bovine serum albumin solution was slowly added to block the non-specific binding sites on the surface of the material. After vigorous shaking for 0.5 hours, the mixture was centrifuged and washed. Finally, the product was dispersed in 2 mL of pH 4 phosphate buffer and stored at 4°C for later use. 3. The preparation steps of the aforementioned optoelectronic material ZnIn2S4 are as follows: Preparation of ZnIn2S4 material: First, 0.5 g of zinc nitrate and 0.1 g of indium nitrate were dissolved in 10 mL of deionized water and stirred for 20 minutes under magnetic stirring. Then, copper nitrate and indium nitrate solutions were mixed and stirred thoroughly. The mixed solution was transferred to a reaction vessel and subjected to hydrothermal reaction at 80℃ for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, the precipitate was collected by centrifugation and washed several times with deionized water. The washed precipitate was dried at 50℃ for 8 hours and then calcined at 150-180℃ for 60 minutes. Finally, after cooling to room temperature, the solid powder was ground to obtain ZnIn2S4 nanomaterials. 4. The organic photoelectrochemical transistor is prepared by the following steps: The source and drain electrodes were integrated with an organic semiconductor layer to construct a conductive channel, and a photosensitive gate electrode was used as the control terminal. The specific fabrication steps are as follows: First, a glass substrate with a size of 15 mm × 18 mm was ultrasonically cleaned with acetone, ethanol and ultrapure water in sequence, followed by drying. After fixing the mask on the substrate, a 12 nm thick chromium layer and an 80 nm thick gold layer were sequentially prepared by magnetron sputtering to form the source and drain electrodes. The length and width of the conductive channel between the two electrodes were set to 0.5 mm and 8-10 mm, respectively. After the prepared template was treated with a plasma cleaning device for 4 minutes, a CdS-loaded PEDOT:PSS solution was coated on the surface of the conductive channel using a spin coating device to form a polymer coating. To improve the bonding strength of the coating on the glass substrate, the device was placed in a nitrogen environment and annealed at 150 °C for 1 hour.

Claims

1. A method for preparing an organic photoelectrochemical transistor sensing platform for detecting acetamiprid, characterized in that, The method comprises the following steps: (1) Preparation of second antibody linked iron ion doped polydopamine nanosphere composite material Dopamine hydrochloride 65-75 mg and ferric chloride 0.05-0.1 g are weighed and dissolved in 50-60 mL of deionized water, and then subjected to ultrasonic treatment for 12-15 minutes; the treated solution is transferred to a constant temperature stirrer and continuously stirred at 30-40 DEG C for 2-3 hours; after the reaction is completed, ethanol and deionized water are used for centrifugal washing to neutralization in sequence; and finally the product is obtained through freeze drying; The dried nanomaterial is dispersed in 8 mL of pH 7.4 phosphate buffer solution, 5-6 μg / mL acetamiprid second antibody is added, and oscillation is carried out at room temperature for 0.8 hours; then 1-1.5% bovine serum albumin solution is slowly added to block the non-specific binding sites on the surface of the material, and oscillation is continued for 0.5 hours; after centrifugal washing, the product is finally dispersed in 2 mL of pH 4 phosphate buffer solution and stored at 4 DEG C for standby use; (2) Preparation of an organic photoelectrochemical transistor sensing platform 1) An indium tin oxide conductive glass is cut into a required size and subjected to pre-treatment to prepare an ITO electrode; 2) 80-90 μL of photoelectric material ZnIn2S4 solution with a concentration of 8-10 mg / mL is dropped onto the surface of the ITO electrode, and then placed in a muffle furnace for calcination at 80-150 DEG C for 1-2 hours to enhance the binding strength of the photoelectric material and the electrode; 3) 3-4 μL of mercaptoacetic acid solution with a concentration of 0.8-1 mol / L is dropped on the ZnIn2S4 electrode and incubated for 0.5-0.8 hours; then 2-3 μL of acetamiprid first antibody solution with a concentration of 8-10 μg / mL, 1% bovine serum albumin solution and acetamiprid solution with different concentrations are added in sequence, and placed at 4 DEG C for 40 minutes to realize fixation and modification; 4) 6-8 μL of the prepared second antibody modified polydopamine nanosphere solution is placed at 37 DEG C for 1 hour to enable specific binding of acetamiprid and fixation of the photoelectric material modified electrode on the surface of the electrode; 5) The photoelectric modified electrode and the organic transistor are placed under a workstation for signal testing.

2. The method for preparing an organic photoelectrochemical transistor sensing platform for detecting acetamiprid according to claim 1, wherein, The iron ion doped polydopamine nanosphere is prepared by the following steps: Dopamine hydrochloride 65-75 mg and ferric chloride 0.05-0.1 g are weighed and dissolved in 50-60 mL of deionized water, and then subjected to ultrasonic treatment for 12-15 minutes; the treated solution is transferred to a constant temperature stirrer and continuously stirred at 30-40 DEG C for 2-3 hours; after the reaction is completed, ethanol and deionized water are used for centrifugal washing to neutralization in sequence; and finally the product is obtained through freeze drying; After drying, the nanomaterials are dispersed in 8 mL of pH 7.4 phosphate buffer, 5-6 μg / mL acetamiprid second antibody is added, and oscillation is performed at room temperature for 0.8 hours, then 1-1.5% bovine serum albumin solution is slowly added to block the non-specific binding sites on the surface of the material, and oscillation is continued for 0.5 hours, followed by centrifugal washing, finally, the product is dispersed in 2 mL of pH 4 phosphate buffer, and is stored at 4°C for standby use.

3. The method of claim 1, wherein the method is characterized by: The photoelectric material ZnIn2S4 material has the following preparation steps: The ZnIn2S4 material is prepared as follows: first, 0.5-0.6 g of zinc nitrate and 0.1-0.2 g of indium nitrate are respectively dissolved in 10-15 mL of deionized water, and are stirred under magnetic stirring for 20-25 minutes, then the copper nitrate and indium nitrate solutions are mixed and stirred thoroughly, the mixed solution is transferred to a reaction kettle, and is subjected to hydrothermal reaction at 80-100°C for 8-10 hours, after the reaction is completed, the temperature is cooled to room temperature, the precipitate is collected by centrifugation, and is washed with deionized water for multiple times, the washed precipitate is dried at 50-60°C for 8 hours, then is calcined at 150-180°C for 40-60 minutes, finally, after being cooled to room temperature, the solid powder is ground to obtain the ZnIn2S4 nanomaterial.

4. The method of claim 1, wherein the method is characterized by: The organic photoelectric chemical transistor has the following preparation steps: The source electrode, the drain electrode and the organic semiconductor layer are integrated to construct a conductive channel, and the light-sensitive gate electrode is used as a control end, and the specific preparation steps are as follows: first, the glass substrate with a size of 15 mm × 18 mm is subjected to ultrasonic cleaning with acetone, ethanol and ultrapure water in sequence, then is dried, after the mask plate is fixed on the substrate, a chromium layer with a thickness of 12 nanometers and a gold layer with a thickness of 80 nanometers are prepared in sequence by a magnetron sputtering device to form the source electrode and the drain electrode, the length and width of the conductive channel between the two electrodes are respectively set to 0.4-0.5 millimeters and 8-10 millimeters, the prepared template is subjected to plasma cleaning equipment treatment for 4-5 minutes, and then a CdS-loaded PEDOT:PSS solution is coated on the surface of the conductive channel by using a spin coating device to form a polymer coating, in order to improve the bonding strength of the coating on the glass substrate, the device is placed in a nitrogen environment and is subjected to annealing treatment at 150°C for 1 hour.