Electrochemical method used for rapidly detecting imidacloprid serving as pesticide

Abstract

The invention discloses an electrochemical method used for rapidly detecting imidacloprid serving as a pesticide. The method comprises the steps of ultrasonically dispersing prepared graphene oxide into secondary distilled water, directly dispensing dispersion liquid on the surface of a glassy carbon electrode, and drying by using a dryer, thus preparing a needed electrochemically-modified electrode. The modified electrode prepared by the invention has the characteristics of good electrocatalysis performance on imidacloprid, rapid current response, high flexibility, low detection limit, good reproducibility and stability, and the like, and has the advantages of low preparation cost, simplicity in operation, strong selectivity, environmental friendliness, no toxicity to a human body, and the like. The prepared modified electrode is successfully applied to analysis and detection on the residual imidacloprid in vegetables such as onions, tomatoes, cucumbers, celeries and oilseed rapes, and has good application prospect and a potential application value in the fields of environmental pollution detection and food detection analysis.

Description

technical field

[0001] The invention belongs to the technical field of electrochemical analysis and detection, and in particular relates to an electrochemical method for rapid detection of imidacloprid, a pesticide harmful to the environment. Background technique

[0002] The chemical name of imidacloprid is 1-[(6-chloro-3-pyridyl)methyl]-N-nitroimidazolidin-2-ylamine. Broad-spectrum insecticide with low residues, belonging to nicotinic compounds, has stomach toxicity and contact killing effects. Because imidacloprid has the advantages of low toxicity, broad spectrum, high efficiency, long validity period, good safety, and not easy to produce drug resistance, it can be used for the control of various crop pests, and is widely used in rice, potato, cotton, corn and other crops. However, the extensive, extensive and long-term use of imidacloprid has caused serious impacts on the environment and human beings. There are several methods for the detection of imidacloprid. Hig...

Examples

Embodiment 1

[0023] An electrochemical method for rapid detection of pesticide imidacloprid, said electrochemical method comprising the following steps:

[0024] (1) Preparation of graphene oxide modified glassy carbon electrode (GO / GCE): dilute graphene oxide with double distilled water and then ultrasonically disperse to obtain 1 mg / mL graphene oxide dispersion; then 10 μL graphene oxide The dispersion liquid is drop-coated on the surface of a clean glassy carbon electrode, and after the solvent evaporates, a graphene oxide-modified glassy carbon electrode covered with a sensitive film is obtained.

[0025] (2) Place the graphene oxide-modified glassy carbon electrode obtained in step (1) in a citric acid / disodium hydrogen phosphate buffer solution with a pH value of 7.0, pass nitrogen gas for 20 minutes, add 100 μmol / L imidacloprid, and use a cycle Voltammetry, with a scan rate of 100 mV / s, was used to detect the electrochemical response of the graphene oxide modified glassy carb...

Embodiment 2

[0032] An electrochemical method for rapid detection of pesticide imidacloprid, said electrochemical method comprising the following steps:

[0033] (1) Preparation of graphene oxide modified glassy carbon electrode (GO / GCE): dilute graphene oxide with double distilled water and then ultrasonically disperse to obtain 5 mg / mL graphene oxide dispersion; then 2 μL graphene oxide The dispersion liquid is drop-coated on the surface of a clean glassy carbon electrode, and after the solvent evaporates, a graphene oxide-modified glassy carbon electrode covered with a sensitive film is obtained.

[0034](2) Place the graphene oxide-modified glassy carbon electrode obtained in step (1) in a citric acid / disodium hydrogen phosphate buffer solution with a pH value of 7.0, pass nitrogen gas for 5 minutes, add 0.8 μmol / L imidacloprid, and use cyclic Voltammetry, with a scan rate of 100 mV / s, was used to detect the electrochemical response of the graphene oxide modified glassy carbon e...

Embodiment 3

[0036] An electrochemical method for rapid detection of pesticide imidacloprid, said electrochemical method comprising the following steps:

[0037] (1) Preparation of graphene oxide-modified glassy carbon electrode (GO / GCE): dilute graphene oxide with twice distilled water and then ultrasonically disperse to obtain a 0.1 mg / mL graphene oxide dispersion; then 10 μL graphene oxide The dispersion liquid is drop-coated on the surface of a clean glassy carbon electrode, and after the solvent evaporates, a graphene oxide-modified glassy carbon electrode covered with a sensitive film is obtained.

[0038] (2) Place the graphene oxide-modified glassy carbon electrode obtained in step (1) in a citric acid / disodium hydrogen phosphate buffer solution with a pH value of 7.5, pass nitrogen gas for 20 minutes, add 50 μmol / L imidacloprid, and use a cycle Voltammetry, with a scan rate of 10 mV / s, was used to detect the electrochemical response of the graphene oxide modified glassy car...

technical field

[0001] The invention belongs to the technical field of electrochemical analysis and detection, and in particular relates to an electrochemical method for rapid detection of imidacloprid, a pesticide harmful to the environment. Background technique

[0002] The chemical name of imidacloprid is 1-[(6-chloro-3-pyridyl)methyl]-N-nitroimidazolidin-2-ylamine. Broad-spectrum insecticide with low residues, belonging to nicotinic compounds, has stomach toxicity and contact killing effects. Because imidacloprid has the advantages of low toxicity, broad spectrum, high efficiency, long validity period, good safety, and not easy to produce drug resistance, it can be used for the control of various crop pests, and is widely used in rice, potato, cotton, corn and other crops. However, the extensive, extensive and long-term use of imidacloprid has caused serious impacts on the environment and human beings. There are several methods for the detection of imidacloprid. Hig...

Examples

Embodiment 1

[0023] An electrochemical method for rapid detection of pesticide imidacloprid, said electrochemical method comprising the following steps:

[0024] (1) Preparation of graphene oxide modified glassy carbon electrode (GO / GCE): dilute graphene oxide with double distilled water and then ultrasonically disperse to obtain 1 mg / mL graphene oxide dispersion; then 10 μL graphene oxide The dispersion liquid is drop-coated on the surface of a clean glassy carbon electrode, and after the solvent evaporates, a graphene oxide-modified glassy carbon electrode covered with a sensitive film is obtained.

[0025] (2) Place the graphene oxide-modified glassy carbon electrode obtained in step (1) in a citric acid / disodium hydrogen phosphate buffer solution with a pH value of 7.0, pass nitrogen gas for 20 minutes, add 100 μmol / L imidacloprid, and use a cycle Voltammetry, with a scan rate of 100 mV / s, was used to detect the electrochemical response of the graphene oxide modified glassy carb...

Embodiment 2

[0032] An electrochemical method for rapid detection of pesticide imidacloprid, said electrochemical method comprising the following steps:

[0033] (1) Preparation of graphene oxide modified glassy carbon electrode (GO / GCE): dilute graphene oxide with double distilled water and then ultrasonically disperse to obtain 5 mg / mL graphene oxide dispersion; then 2 μL graphene oxide The dispersion liquid is drop-coated on the surface of a clean glassy carbon electrode, and after the solvent evaporates, a graphene oxide-modified glassy carbon electrode covered with a sensitive film is obtained.

[0034](2) Place the graphene oxide-modified glassy carbon electrode obtained in step (1) in a citric acid / disodium hydrogen phosphate buffer solution with a pH value of 7.0, pass nitrogen gas for 5 minutes, add 0.8 μmol / L imidacloprid, and use cyclic Voltammetry, with a scan rate of 100 mV / s, was used to detect the electrochemical response of the graphene oxide modified glassy carbon e...

Embodiment 3

[0036] An electrochemical method for rapid detection of pesticide imidacloprid, said electrochemical method comprising the following steps:

[0037] (1) Preparation of graphene oxide-modified glassy carbon electrode (GO / GCE): dilute graphene oxide with twice distilled water and then ultrasonically disperse to obtain a 0.1 mg / mL graphene oxide dispersion; then 10 μL graphene oxide The dispersion liquid is drop-coated on the surface of a clean glassy carbon electrode, and after the solvent evaporates, a graphene oxide-modified glassy carbon electrode covered with a sensitive film is obtained.

[0038] (2) Place the graphene oxide-modified glassy carbon electrode obtained in step (1) in a citric acid / disodium hydrogen phosphate buffer solution with a pH value of 7.5, pass nitrogen gas for 20 minutes, add 50 μmol / L imidacloprid, and use a cycle Voltammetry, with a scan rate of 10 mV / s, was used to detect the electrochemical response of the graphene oxide modified glassy car...

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