High-sensitivity rapid electrical analysis detection method for imidacloprid based on carbon nanosensor

Abstract

The invention discloses an imidacloprid high-sensitivity rapid electrical analysis detection method based on a carbon nanosensor, and relates to the field of chemical analysis. The preparation method comprises the following steps: firstly, mixing a carbon nanotube and hexa [(trimethylsilyl) ethynyl] benzene in N, N-dimethylformamide, and continuously stirring; then adding CuCl, heating in a reaction kettle at 60 DEG C for 24 hours, filtering, washing and drying to obtain carbon nanotube-graphdiyne; dispersing the carbon nanotube at graphdiyne in ultrapure water, performing uniform ultrasonic treatment to obtain a suspension liquid, dropwise adding the suspension liquid to the surface of a polished glassy carbon electrode, and drying to obtain a modified electrode material, namely the carbon nanotube at graphdiyne / glassy carbon electrode; and preparing a to-be-detected solution containing a to-be-detected substance imidacloprid, finally inserting the modified electrode substance carbon nanotube and graphdiyne / glassy carbon electrode into the to-be-detected solution, and carrying out concentration determination by adopting a differential pulse voltammetry. According to the invention, rapid and high-sensitivity detection of imidacloprid is finally realized through preparation of the carbon nanotube-graphdiyne material, electrode modification and electrochemical determination in sequence.

Description

Technical Field

[0001] This invention relates to the field of chemical analysis, specifically a highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor. Background Technology

[0002] Imidacloprid is a nitromethylene systemic insecticide, belonging to the neonicotinoid class. It possesses broad-spectrum, high-efficiency, low-toxicity, and low-residue properties, making it difficult for pests to develop resistance. It exhibits multiple effects, including contact, stomach poison, and systemic action. Upon contact with the pesticide, the normal conduction of the central nervous system is blocked, leading to paralysis and death. The product has a rapid onset of action, showing high efficacy within one day of application, with a residual period of approximately 25 days. Its efficacy is positively correlated with temperature; higher temperatures result in better insecticidal effects. It is primarily used to control piercing-sucking pests. Currently, many techniques, such as high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), surface Raman spectroscopy, and fluorescence spectroscopy, are used for the detection of imidacloprid. However, most of these methods have drawbacks: high equipment requirements, cumbersome sample pretreatment, and time-consuming processes. Electrochemical technology, on the other hand, is characterized by low cost, simple equipment, and fast response speed, and has been widely applied in various chemical / biological sensing studies. However, developing a simple and highly sensitive electrochemical sensing method for imidacloprid remains a huge challenge. Summary of the Invention

[0003] The purpose of this invention is to provide a rapid and highly sensitive method for detecting imidacloprid. This method sequentially involves the preparation of carbon nanotube@graphyne material, electrode modification, and electrochemical measurement, ultimately achieving rapid and highly sensitive detection of imidacloprid.

[0004] The objective of this invention is achieved as follows:

[0005] A highly sensitive and rapid electroanalytical detection method for imidacloprid based on carbon nanotube sensors includes the following steps:

[0006] Step a: Mix carbon nanotubes and hexa[(trimethylsilyl)ethynyl]benzene in N,N-dimethylformamide and stir continuously to obtain solution A;

[0007] Step b: Add CuCl to solution A and heat in a reaction vessel at 60°C for 24 hours to obtain solution B;

[0008] Step c: Filter, wash and dry the solution B to obtain the final product carbon nanotubes@graphyne;

[0009] Step d: Disperse the carbon nanotubes@graphyne in ultrapure water and sonicate to obtain a uniform suspension;

[0010] Step e: Transfer the suspension droplet onto the surface of the polished glassy carbon electrode, dry it, and obtain the modified electrode material carbon nanotube@graphyne / glassy carbon electrode;

[0011] Step f: Adjust the pH of the solution containing the analyte imidacloprid to 6.5-7.5 to obtain the test solution;

[0012] Step g: Insert the modified electrode material carbon nanotube@graphyne / glassy carbon electrode into the test solution, enrich it for 2-4 min, and then determine the concentration using differential pulse voltammetry.

[0013] The above-mentioned highly sensitive and rapid electroanalytical detection method for imidacloprid based on carbon nanotube sensors, wherein the mass ratio of carbon nanotubes and hexa[(trimethylsilyl)ethynyl]benzene in step a is 1:10-10:1.

[0014] In the above-mentioned highly sensitive and rapid electroanalytical detection method for imidacloprid based on carbon nanotube sensors, the mass ratio of CuCl in step b to carbon nanotubes in step a is 1:1 to 1:100.

[0015] The above-mentioned highly sensitive and rapid electroanalytical detection method for imidacloprid based on carbon nanotube sensors, wherein the mass ratio of carbon nanotubes@graphyne to ultrapure water in step d is 1:1000-1:3000.

[0016] In the aforementioned highly sensitive and rapid electroanalytical detection method for imidacloprid based on carbon nanotube sensors, the modification amount of the modified electrode material, carbon nanotube@graphyne / glassy carbon electrode, in step e is 40-60 μg / cm³. 2 .

[0017] The beneficial effects of this invention's highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor are as follows: the synergistic effect of carbon nanotubes@graphyne acts as a nanosensor, enabling rapid and highly sensitive detection of imidacloprid, wherein:

[0018] First, after obtaining the modified electrode material carbon nanotube@graphyne / glassy carbon electrode, the concentration determination can be completed in just three steps: preparing the test solution, enriching for 2-4 minutes, and using differential pulse voltammetry, which demonstrates its speed.

[0019] Secondly, the detection limit can reach 2.5nM, demonstrating high sensitivity. Attached Figure Description

[0020] Figure 1 This is a scanning electron microscope image of carbon nanotubes@graphyne obtained in this invention.

[0021] Figure 2 This is a transmission electron microscope (TEM) image of carbon nanotubes@graphyne obtained in this invention.

[0022] Figure 3 This is a concentration calibration curve for the experimental detection of imidacloprid in this invention. Detailed Implementation

[0023] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0024] Method 1

[0025] The following is a detailed implementation of the highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor according to the present invention.

[0026] The highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor, as described in this specific embodiment, includes the following steps:

[0027] Step a: Mix carbon nanotubes and hexa[(trimethylsilyl)ethynyl]benzene in N,N-dimethylformamide and stir continuously to obtain solution A;

[0028] Step b: Add CuCl to solution A and heat in a reaction vessel at 60°C for 24 hours to obtain solution B;

[0029] Step c: Filter, wash and dry the solution B to obtain the final product carbon nanotubes@graphyne;

[0030] Step d: Disperse the carbon nanotubes@graphyne in ultrapure water and sonicate to obtain a uniform suspension;

[0031] Step e: Transfer the suspension droplet onto the surface of the polished glassy carbon electrode, dry it, and obtain the modified electrode material carbon nanotube@graphyne / glassy carbon electrode;

[0032] Step f: Adjust the pH of the solution containing the analyte imidacloprid to 6.5-7.5 to obtain the test solution;

[0033] Step g: Insert the modified electrode material carbon nanotube@graphyne / glassy carbon electrode into the test solution, enrich it for 2-4 min, and then determine the concentration using differential pulse voltammetry.

[0034] Method 2

[0035] The following is a detailed implementation of the highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor according to the present invention.

[0036] The highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor in this specific embodiment, based on specific embodiment one, is subject to at least one of the following four limitations:

[0037] First, the mass ratio of the carbon nanotubes and hexa[(trimethylsilyl)ethynyl]benzene in step a is 1:10-10:1.

[0038] Second, the mass ratio of CuCl in step b to carbon nanotubes in step a is 1:1 to 1:100.

[0039] Third, the mass ratio of carbon nanotubes@graphyne to ultrapure water in step d is 1:1000-1:3000.

[0040] Fourth, the modification amount of the carbon nanotube@graphyne / glassy carbon electrode described in step e is 40-60 μg / cm³. 2 .

[0041] Method 3

[0042] The following is a detailed implementation of the experimental method for the highly sensitive and rapid electroanalytical detection of imidacloprid based on a carbon nanotube sensor according to the present invention.

[0043] Step a: Mix 15 mg of carbon nanotubes and 30 mg of hexa[(trimethylsilyl)ethynyl]benzene in 6 mL of N,N-dimethylformamide and stir continuously for 10 min to obtain solution A;

[0044] Step b: Add 5 mg CuCl to solution A and heat in a reaction vessel at 60 °C for 24 h to obtain solution B;

[0045] Step c: Filter, wash, and dry the solution B, specifically by drying it in a vacuum drying oven at 60°C for 12 hours to obtain a dark brown powder. Then, treat with 0.5M HCl to remove CuO, followed by filtration, washing, and drying to obtain the final product, carbon nanotubes@graphyne. The scanning electron microscope image of the carbon nanotubes@graphyne is shown below. Figure 1 As shown, the transmission electron microscope image is as follows: Figure 2 As shown, from Figure 1 and Figure 2 It can be seen that graphyne has been successfully grown on the surface of carbon nanotubes;

[0046] Step d: Disperse 3 mg of the carbon nanotubes@graphyne in 6 mL of ultrapure water and sonicate to obtain a uniform suspension;

[0047] Step e: Use a pipette to transfer the suspension droplet onto the polished glassy carbon electrode surface with a diameter of 3 mm, and dry it with an infrared lamp to obtain the modified electrode material carbon nanotube@graphyne / glassy carbon electrode. The amount of composite modification on the electrode surface is 50 μg / cm2.

[0048] Step f: Adjust the pH of the solution containing the analyte imidacloprid to 7.0 to obtain the test solution;

[0049] Step g: Insert the modified electrode material carbon nanotube@graphyne / glassy carbon electrode into the test solution, enrich it for 3 min, and then determine the concentration using differential pulse voltammetry.

[0050] The concentration-calibrated curve for electrochemical detection of imidacloprid using the prepared carbon nanotube@graphyne is shown in the figure below. Figure 3 As shown, from Figure 3It can be seen that the linear range is 5.0-400.0 nM and the detection limit is 2.5 nM.

[0051] It should be noted that the above are merely specific embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0052] It should also be noted that all the technical features listed in the above specific embodiments can be arranged and combined, as long as they are not contradictory. Those skilled in the art can exhaustively calculate the result of each arrangement and combination based on the mathematical knowledge of permutations and combinations learned in high school. All the results of permutations and combinations should be understood as being disclosed in this application.

Claims

1. A highly sensitive and rapid electroanalytical detection method for imidacloprid based on carbon nanotube sensors, characterized in that: Includes the following steps: Step a: Mix carbon nanotubes and hexa[(trimethylsilyl)ethynyl]benzene in N,N-dimethylformamide and stir continuously to obtain solution A; Step b: Add CuCl to solution A and heat in a reaction vessel at 60°C for 24 hours to obtain solution B; Step c: Filter, wash and dry the solution B to obtain the final product carbon nanotubes@graphyne; Step d: Disperse the carbon nanotubes@graphyne in ultrapure water and sonicate to obtain a uniform suspension; Step e: Transfer the suspension droplet onto the surface of the polished glassy carbon electrode, dry it, and obtain the modified electrode material carbon nanotube@graphyne / glassy carbon electrode; Step f: Adjust the pH of the solution containing the analyte imidacloprid to 6.5-7.5 to obtain the test solution; Step g: Insert the modified electrode material carbon nanotube@graphyne / glassy carbon electrode into the test solution, enrich it for 2-4 min, and then determine the concentration using differential pulse voltammetry.

2. The highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor according to claim 1, characterized in that: The mass ratio of the carbon nanotubes and hexa[(trimethylsilyl)ethynyl]benzene in step a is 1:10-10:

1.

3. The highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor according to claim 1, characterized in that: The mass ratio of CuCl in step b to carbon nanotubes in step a is 1:1 to 1:

100.

4. The highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor according to claim 1, characterized in that: The mass ratio of carbon nanotubes@graphyne to ultrapure water in step d is 1:1000-1:3000.

5. The highly sensitive and rapid electroanalytical detection method for imidacloprid based on a carbon nanotube sensor according to claim 1, characterized in that: The modification amount of the carbon nanotube@graphyne / glassy carbon electrode described in step e is 40-60 μg / cm³. 2 .

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