Device for detecting pesticide in water based on nano-composite hydrogel and preparation method

Abstract

The invention provides a device for detecting pesticide in water based on nano-composite hydrogel and a preparation method. The device comprises first hydrogel and second hydrogel which are attached to each other, first ITO conductive glass is attached to the side, away from the second hydrogel, of the first hydrogel, second ITO conductive glass is attached to the side, away from the first hydrogel, of the second hydrogel, and the first ITO conductive glass and the second ITO conductive glass are covered with ITO films; the ITO film is connected with a voltage detection unit through a wire, and the voltage detection unit is connected with a display; the wall surface of the porous structure in the first hydrogel is positively charged and has anion selectivity; the wall surface of the porous structure in the second hydrogel is negatively charged and has cation selectivity. According to the invention, the information of the pesticide in water can be judged by detecting the voltage signal by utilizing an ion diffusion migration mechanism, and the method has the advantages of high detection speed, portability, easiness in operation and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide detection in water, and in particular to a pesticide detection device in water based on nanocomposite hydrogel and a preparation method thereof. Background Art

[0002] Agricultural development is inseparable from pesticides, which protect crops from pests, pathogens, weeds, and other harmful organisms, thereby increasing crop yields. However, with the widespread use of pesticides, factors such as farmland irrigation and rainwater runoff have led to the entry of pesticide residues into environmental water bodies, raising concerns about pesticide contamination in environmental water. Pesticide residue contamination in environmental water has direct toxic effects on aquatic organisms, inhibiting their growth and reproduction, and even causing their death. It can also cause the death of important algae and plankton, thereby affecting the stability of the entire food chain and posing a threat to higher organisms such as fish and birds. Furthermore, pesticide residues in environmental water pose potential risks to human health. Therefore, detecting pesticide residues in environmental water is of great significance for ensuring health and safety.

[0003] Current methods for pesticide residue detection include spectroscopy, enzyme inhibition, and chromatography. Spectroscopy can adapt to the needs of different pesticide analyses, allowing for rapid detection of pesticide residues and improving sample processing efficiency. However, due to the presence of multiple pesticide residues in environmental water and the complex matrix content, spectroscopy cannot effectively separate the target compounds and often has sensitivity limitations in detecting low-concentration pesticide residues. Enzyme inhibition offers high sensitivity for pesticide residue detection and can be designed for specific enzymes and pesticides, resulting in strong specificity. However, enzymes are expensive and susceptible to factors such as temperature and pH, which can alter enzyme activity. Chromatography offers advantages in pesticide residue detection, including high resolution, high sensitivity, high selectivity, and a wide range of applications. However, the instrumentation is expensive and limited to the analysis and detection of volatile compounds. Therefore, a highly sensitive, portable, and easy-to-use device for detecting pesticides in water is needed. Summary of the Invention

[0004] In response to the aforementioned technical issues that existing water pesticide detection devices cannot achieve both high sensitivity and low cost, a water pesticide detection device based on nanocomposite hydrogels and a preparation method are provided. The present invention primarily utilizes the mechanism of ion diffusion and migration to determine the presence of pesticides in water by detecting voltage signals.

[0005] The technical means adopted in the present invention are as follows: A nanocomposite hydrogel-based water pesticide detection device comprises a first hydrogel and a second hydrogel bonded together; a first ITO conductive glass is attached to a side of the first hydrogel away from the second hydrogel, and a second ITO conductive glass is attached to a side of the second hydrogel away from the first hydrogel; the first and second ITO conductive glasses are covered with an ITO film; the ITO film is connected to a voltage detection unit via a wire, and the voltage detection unit is connected to a display; The first hydrogel is an elastic solid with a porous structure. The first hydrogel contains cations. The wall surface of the porous structure inside the first hydrogel is positively charged and has anion selectivity. The interior of the second hydrogel is an elastic solid with a porous structure, and the interior of the second hydrogel contains anions; the wall surface of the porous structure inside the second hydrogel is negatively charged and has cation selectivity.

[0006] Furthermore, the first hydrogel is an Al2O3 / CS nanocomposite hydrogel, and the second hydrogel is a MIP / CS nanocomposite hydrogel.

[0007] Furthermore, the first hydrogel and the second hydrogel are the same size, 3 cm in length, 2 cm in width, and 1 cm in height.

[0008] Furthermore, the main bodies of the first hydrogel and the second hydrogel are chitosan and polyvinyl alcohol, and microcrystalline cellulose is added; The first hydrogel is doped with MIP nanoparticles; the second hydrogel is doped with nano-alumina particles.

[0009] Furthermore, the first ITO conductive glass and the second ITO conductive glass are of the same size, 6 cm in length and 6 cm in width. The material of the ITO film is indium tin oxide, and the ITO film is a 4 cm square.

[0010] Furthermore, the MIP nanoparticles are prepared by a precipitation method, and the diameter of the MIP nanoparticles ranges from 100 to 300 nm. The MIP nanoparticles have pesticide recognition sites on their surfaces, which can selectively adsorb pesticide molecules, thereby inducing changes in surface charge density.

[0011] The present invention also provides a method for preparing a nanocomposite hydrogel-based water pesticide detection device, which is used to prepare any of the above-mentioned nanocomposite hydrogel-based water pesticide detection devices, comprising the following steps: S1, preparation of MIP nanoparticles; S11, selecting pesticide as template molecule; S12, dissolving methacrylic acid, ethylene glycol dimethacrylate, azobisisobutyronitrile and the template molecule in acetonitrile, an organic solvent, to obtain a prepolymerization solution, and prepolymerizing in an environment; S13, purging the prepolymerization solution with high-purity nitrogen for 10 minutes to remove oxygen in the prepolymerization solution, then heating the solution in a water bath and stirring the solution to obtain molecularly imprinted nanoparticles; S14, suspending the nanoparticles in a mixed solution of methanol and acetic acid and performing ultrasonic treatment to elute the template molecules to obtain MIP nanoparticles; S15, weighing a certain mass of MIP nanoparticles, suspending them in pure water, and preparing a MIP nanoparticle suspension; S2. Preparation of hydrogel: S21, adding sodium hydroxide and urea to pure water and stirring thoroughly to dissolve; weighing microcrystalline cellulose and adding it to the above solution to obtain a white suspension; placing the obtained white suspension at a fixed temperature for a fixed time, taking it out and dissolving it at room temperature with stirring to obtain a transparent cellulose solution; S22, adding chitosan to acetic acid and dissolving it under magnetic stirring to obtain a first solution; adding polyvinyl alcohol to pure water and dissolving it under heating and stirring to obtain a second solution; mixing the first solution and the second solution, and stirring and mixing them thoroughly to obtain a mixed solution; dropping the mixed solution into a NaOH solution to obtain an alkalized chitosan polyvinyl alcohol; S23, taking a cellulose solution, adding epichlorohydrin, stirring, adding the prepared nano-alumina particle suspension, and then adding alkalized chitosan polyvinyl alcohol, stirring thoroughly and heating to obtain a composite hydrogel, soaking in a potassium chloride solution to remove unreacted reactants, potassium chloride can provide carriers, to obtain an Al2O3 / CS nanocomposite hydrogel; S24, taking a cellulose solution, adding epichlorohydrin, stirring, adding the prepared MIP nanoparticle suspension, and then adding alkalized chitosan polyvinyl alcohol, stirring thoroughly and heating to obtain a composite hydrogel, soaking in a potassium chloride solution to remove unreacted reactants, potassium chloride can provide carriers, to obtain a MIP / CS nanocomposite hydrogel; S3, pesticide detection device integration; The MIP / CS nanocomposite hydrogel and Al2O3 / CS nanocomposite hydrogel obtained in S2 were laminated together, and two ITO conductive glasses were laminated between the MIP / CS nanocomposite hydrogel and Al2O3 / CS nanocomposite hydrogel. 3 / Both sides of the CS nanocomposite hydrogel; the ITO film is connected to the voltage detection unit through a wire, and the voltage detection unit is connected to the display.

[0012] Furthermore, the template molecules include omethoate, dimethoate, acephate, and phosmet.

[0013] Compared with the prior art, the present invention has the following advantages: The nanocomposite hydrogel-based water pesticide detection device provided by the present invention has the advantages of portability, high precision, and small size, and is suitable for application scenarios of water pesticide detection. The nanocomposite hydrogel-based water pesticide detection device provided by the present invention has good specificity and is suitable for the detection and analysis of complex samples. It does not require complex pre-treatment of the samples, thus saving detection time. The invention forms a new method for preparing a water pesticide detection device based on nanocomposite hydrogel, which has the advantages of simple preparation method, low cost, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0015] Figure 1 Schematic diagram of the device of the present invention.

[0016] Figure 2 This is an electron microscope image of the MIP nanoparticles of the present invention.

[0017] Figure 3 Schematic diagram of the internal electrical behavior of the hydrogel of the present invention.

[0018] Figure 4 This is the electrochemical signal diagram of the hydrogel before and after adsorption of target molecules of the present invention.

[0019] In the figure: 1. first hydrogel; 2. second hydrogel; 31. first ITO conductive glass; 32. second ITO conductive glass; 4. voltage detection unit; 5. display. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0024] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0025] For ease of description, spatially relative terms such as "above," "above," "on the upper surface of," and "above" may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "on top of" another device or structure would then be positioned as "below" or "below" the other device or structure. Thus, the exemplary term "above" may include both the orientations of "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0026] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0027] like Figure 1 As shown, the present invention provides a water pesticide detection device based on nanocomposite hydrogel, comprising a first hydrogel 1 and a second hydrogel 2 bonded together; a first ITO conductive glass 31 is attached to the side of the first hydrogel 1 away from the second hydrogel 2, and a second ITO conductive glass 32 is attached to the side of the second hydrogel 2 away from the first hydrogel 1, and the first ITO conductive glass 31 and the second ITO conductive glass 32 are covered with an ITO film; the ITO film is connected to a voltage detection unit 4 via a wire, and the voltage detection unit 4 is connected to a display 5; the first hydrogel 1 is an Al2O3 / CS nanocomposite hydrogel, and the second hydrogel 2 is an MIP / CS nanocomposite hydrogel.

[0028] The interior of the first hydrogel 1 is an elastic solid with a porous structure. The interior of the first hydrogel 1 contains cations. The wall surface of the porous structure inside the first hydrogel 1 is positively charged and has anion selectivity. The interior of the second hydrogel 2 is an elastic solid with a porous structure, and the interior of the second hydrogel 2 contains anions; the wall surface of the porous structure inside the second hydrogel 2 is negatively charged and has cation selectivity. The MIP / CS nanocomposite hydrogel is a hydrogel with a bulk doped with MIP nanoparticles. The addition of the MIP nanoparticles causes the porous wall surface of the hydrogel to be negatively charged, thus exhibiting cation selectivity. The Al2O3 / CS nanocomposite hydrogel is a hydrogel with a bulk doped with nanoalumina particles. The porous wall surface of the hydrogel is positively charged, thus exhibiting anion selectivity. The MIP / CS nanocomposite hydrogel and the Al2O3 / CS nanocomposite hydrogel are bonded together. The MIP nanoparticles are prepared by a precipitation method, have a diameter of 100-300 nm, and have pesticide recognition sites on their surface, which can selectively adsorb pesticide molecules, thereby causing changes in surface charge density. The MIP / CS nanocomposite hydrogel and the Al2O3 / CS nanocomposite hydrogel were laminated together, with a first ITO conductive glass 31 and a second ITO conductive glass 32 attached to each side of the hydrogel. The first and second ITO conductive glasses 31 and 32 were of equal length and width, measuring 6 cm. The ITO film, made of indium tin oxide and with negligible thickness, was applied to the ITO conductive glass, measuring a 4 cm square. The voltage detection unit 4 is connected to the ITO film through a wire to measure the electrochemical signal and convert the measured analog signal into a digital signal through digital-to-analog conversion. The voltage detection unit 4 is connected to the display 5, which is a liquid crystal display screen for displaying the voltage signal detected by the voltage detection unit; When specifically implemented, as a preferred embodiment of the present invention, Figure 2 As shown, Figure 2 This is an electron micrograph of MIP nanoparticles. MIP nanoparticles were prepared by a precipitation method and have a diameter of 200 nm. The pesticide omethoate is used as a template molecule. The MIP nanoparticles have recognition sites for omethoate on their surface, which can selectively adsorb omethoate, triggering changes in surface charge density. The detection principle of the present invention is as follows: like Figure 3 and Figure 4 As shown, when two hydrogels are connected together, the mobile cations and anions diffuse into each other's areas driven by entropy. This diffusion process will cause a change in ion concentration, forming an ion depletion region at the contact surface and generating a built-in potential at the junction to counteract further diffusion and complete the equilibrium state.

[0029] Because the MIP / CS nanocomposite hydrogel contains MIP nanoparticles, which have specific imprinting sites for omethoate, when the MIP / CS nanocomposite hydrogel is immersed in an aqueous solution containing omethoate, omethoate occupies the specific sites on the MIP nanoparticles, changing the surface charge density of the molecularly imprinted nanoparticles. This lowers the surface charge density, disrupting the equilibrium. The ion distribution in the new equilibrium state adjusts accordingly, and the built-in potential decreases. Therefore, by detecting changes in the electrochemical signal, information about the pesticide concentration in the sample can be obtained.

[0030] The present invention also provides a method for preparing a water pesticide detection device based on nanocomposite hydrogel, comprising the following steps: S1. Preparation of MIP nanoparticles: S11. Select pesticide as template molecule, taking omethoate as an example; S12, dissolving methacrylic acid, ethylene glycol dimethacrylate, azobisisobutyronitrile, and omethoate in acetonitrile, an organic solvent, to obtain a prepolymerization solution, and prepolymerizing at 4° C. for 2 h; S13, purging the prepolymerization solution with high-purity nitrogen for 10 minutes to remove oxygen in the solution, then heating the solution in a water bath, and stirring the solution at 60° C. for 24 hours to obtain molecularly imprinted nanoparticles; S14, suspending the nanoparticles in a mixed solution of methanol and acetic acid with a mass ratio of 9:1 and performing ultrasonic treatment to elute the template molecules; S15, weighing a certain mass of MIP nanoparticles, suspending them in pure water to prepare a nanoparticle suspension; S2. Preparation of hydrogel: S21, 3g sodium hydroxide and 6g urea are added to 50mL pure water, fully stirred and dissolved.Weigh 3g microcrystalline cellulose and join in above-mentioned solution, obtain white suspension.The white suspension obtained is placed in-20 DEG C of refrigerators and spend the night, takes out and dissolves stirring at room temperature, obtains transparent cellulose solution for subsequent use.

[0031] S22, 1g CS was added to 50mL of 2% acetic acid and dissolved under magnetic stirring. 1g polyvinyl alcohol was added to 50mL of pure water and dissolved under heating and stirring. The above two solutions were mixed in a 1:1 ratio and thoroughly stirred to mix. At 200rpm, the mixed solution was dropwise added to a 1mol / L NaOH solution to obtain alkalized chitosan polyvinyl alcohol.

[0032] S23. Take 5 mL of cellulose solution, add 0.5 mL of epichlorohydrin, stir at 500 rpm for 1 hour, add 20 μL of the prepared nano-alumina particle suspension, and then add alkalized chitosan polyvinyl alcohol. After sufficient stirring, place in a 60°C oven and heat for 5 hours to obtain a composite hydrogel. Immerse in 1 mM potassium chloride solution to remove unreacted reactants. Potassium chloride can provide carriers to obtain Al2O3 / CS nanocomposite hydrogel.

[0033] S24, taking 5 mL of cellulose solution, adding epichlorohydrin, stirring, adding the prepared MIP nanoparticle suspension, and then adding alkalized chitosan polyvinyl alcohol, stirring thoroughly and heating to obtain a composite hydrogel, soaking in potassium chloride solution to remove unreacted reactants, potassium chloride can provide carriers, to obtain MIP / CS nanocomposite hydrogel; S3, integration of pesticide detection devices; The MIP / CS nanocomposite hydrogel and the Al2O3 / CS nanocomposite hydrogel obtained in S2 are laminated together, and two ITO conductive glasses 3 are laminated on both sides of the two hydrogels 1 and 2; the ITO film is connected to the voltage detection unit 4 through a wire, and the voltage detection unit 4 is connected to the display 5; Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for detecting pesticides in water based on nanocomposite hydrogel, characterized by: The device comprises a first hydrogel and a second hydrogel bonded together; a first ITO conductive glass is attached to a side of the first hydrogel away from the second hydrogel, and a second ITO conductive glass is attached to a side of the second hydrogel away from the first hydrogel; the first ITO conductive glass and the second ITO conductive glass are covered with an ITO film; the ITO film is connected to a voltage detection unit via a wire, and the voltage detection unit is connected to a display; The first hydrogel is an elastic solid with a porous structure. The first hydrogel contains cations. The wall surface of the porous structure inside the first hydrogel is positively charged and has anion selectivity. The interior of the second hydrogel is an elastic solid with a porous structure, and the interior of the second hydrogel contains anions; the wall surface of the porous structure inside the second hydrogel is negatively charged and has cation selectivity.

2. The nanocomposite hydrogel-based water pesticide detection device according to claim 1, characterized in that: The first hydrogel is an Al2O3 / CS nanocomposite hydrogel, and the second hydrogel is a MIP / CS nanocomposite hydrogel.

3. The nanocomposite hydrogel-based water pesticide detection device according to claim 1, characterized in that: The first hydrogel and the second hydrogel are of the same size, 3 cm in length, 2 cm in width, and 1 cm in height.

4. The nanocomposite hydrogel-based water pesticide detection device according to claim 1, characterized in that: The main components of the first hydrogel and the second hydrogel are chitosan and polyvinyl alcohol, and microcrystalline cellulose is added; The first hydrogel is doped with MIP nanoparticles; the second hydrogel is doped with nano-alumina particles.

5. The nanocomposite hydrogel-based water pesticide detection device according to claim 1, characterized in that: The first ITO conductive glass and the second ITO conductive glass have the same size, 6 cm in length and 6 cm in width. The material of the ITO film is indium tin oxide, and the ITO film is a 4 cm square.

6. The nanocomposite hydrogel-based water pesticide detection device according to claim 4, characterized in that: The MIP nanoparticles are prepared by a precipitation method, and the diameter of the MIP nanoparticles ranges from 100 to 300 nm. The surfaces of the MIP nanoparticles have pesticide recognition sites that can selectively adsorb pesticide molecules, thereby inducing changes in surface charge density.

7. A method for preparing a nanocomposite hydrogel-based water pesticide detection device, for preparing the nanocomposite hydrogel-based water pesticide detection device according to any one of claims 1 to 6, characterized in that: The steps include: S1, preparation of MIP nanoparticles; S11, selecting pesticide as template molecule; S12, dissolving methacrylic acid, ethylene glycol dimethacrylate, azobisisobutyronitrile and the template molecule in acetonitrile, an organic solvent, to obtain a prepolymerization solution, and prepolymerizing in an environment; S13, purging the prepolymerization solution with high-purity nitrogen for 10 minutes to remove oxygen in the prepolymerization solution, then heating the solution in a water bath and stirring the solution to obtain molecularly imprinted nanoparticles; S14, suspending the nanoparticles in a mixed solution of methanol and acetic acid and performing ultrasonic treatment to elute the template molecules to obtain MIP nanoparticles; S15, weighing a certain mass of MIP nanoparticles, suspending them in pure water, and preparing a MIP nanoparticle suspension; S2. Preparation of hydrogel: S21, adding sodium hydroxide and urea to pure water and stirring thoroughly to dissolve; weighing microcrystalline cellulose and adding it to the above solution to obtain a white suspension; placing the obtained white suspension at a fixed temperature for a fixed time, taking it out and dissolving it at room temperature with stirring to obtain a transparent cellulose solution; S22, adding chitosan to acetic acid and dissolving it under magnetic stirring to obtain a first solution; Adding polyvinyl alcohol to pure water, heating and stirring to dissolve, to obtain a second solution; mixing the first solution and the second solution, and stirring and mixing thoroughly to obtain a mixed solution; dropping the mixed solution into a NaOH solution to obtain an alkaline chitosan polyvinyl alcohol; S23, taking a cellulose solution, adding epichlorohydrin, stirring, adding the prepared nano-alumina particle suspension, and then adding alkalized chitosan polyvinyl alcohol, stirring thoroughly and heating to obtain a composite hydrogel, soaking in a potassium chloride solution to remove unreacted reactants, potassium chloride can provide carriers, to obtain an Al2O3 / CS nanocomposite hydrogel; S24, taking a cellulose solution, adding epichlorohydrin, stirring, adding the prepared MIP nanoparticle suspension, and then adding alkalized chitosan polyvinyl alcohol, stirring thoroughly and heating to obtain a composite hydrogel, soaking in a potassium chloride solution to remove unreacted reactants, potassium chloride can provide carriers, to obtain a MIP / CS nanocomposite hydrogel; S3, pesticide detection device integration; The MIP / CS nanocomposite hydrogel and Al2O3 / CS nanocomposite hydrogel obtained in S2 were laminated together, and two ITO conductive glasses were laminated between the MIP / CS nanocomposite hydrogel and Al2O3 / CS nanocomposite hydrogel. 3 / Both sides of CS nanocomposite hydrogel; The ITO film is connected to a voltage detection unit through a wire, and the voltage detection unit is connected to a display.

8. The method for preparing the water pesticide detection device based on nanocomposite hydrogel according to claim 7, characterized in that: The template molecules include omethoate, dimethoate, acephate and phosmet.

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