金纳米颗粒修饰分子印迹电化学传感器快速检测蔬菜中吡虫啉含量

Rapid detection of imidacloprid in vegetables using a molecularly imprinted electrochemical sensor modified with gold nanoparticles

中文关键词:  食品安全  农药残留  分子印迹  电化学传感器  快速检测

英文关键词:food safety  pesticide residues  molecular imprinting  electrochemical sensor  rapid detection

中文摘要:

      目的 将分子印迹技术、电化学技术和纳米颗粒修饰技术相结合, 开发蔬菜中吡虫啉的快速检测技术。方法 采用金纳米颗粒修饰玻碳电极提高其电子转移速率, 通过分子印迹技术在电极表面聚合膜材料制备电化学传感器, 利用循环伏安法和差分脉冲法表征传感器性能, 基于传感器对目标农药分子的特异性吸附建立农药快速检测方法。结果 以吡虫啉为模板分子, 邻苯二胺为功能单体, 基于金纳米颗粒修饰的玻碳电极构建了一种吡虫啉分子印迹电化学传感器, 该传感器可实现对吡虫啉的特异性识别检测, 在1.0×10–11~1.0×10–4 mol/L浓度范围内, 吡虫啉线性关系良好, 相关系数为0.9951, 检出限为3.3×10–12 mol/L, 小白菜样品加标回收率为91.86%~102.25%, 相对标准偏差为1.98%~3.19%。结论 本研究制备的传感器具有优良的选择性、重复性和稳定性, 适用于蔬菜中吡虫啉的快速检测, 为当前农残速测产品的开发提供了参考。

英文摘要:

      Objective To develop a rapid detection technique for rapid determination imidacloprid in vegetables by combining molecular imprinting technology, electrochemical technology and nanoparticle modification technology. Methods The electron transfer rate of glass carbon electrode was improved by modifying gold nanoparticles, and the electrochemical sensor was prepared by polymerizing film material on the electrode surface by molecular imprinting technique. The sensor’s performance was tested and characterized using cyclic voltammetry and differential pulse method. A rapid detection method was established based on the specific adsorption of target pesticide molecules by the sensor. Results The study used imidacloprid as a template molecule and o-phenylenediamine as a functional monomer to construct an imidacloprid molecular-imprinted electrochemical sensor. This was based on a gold nanoparticle-modified glass carbon electrode. The sensor was able to recognize and detect imidacloprid specifically. The sensor proved to be effective in the concentration range of 1.0×10–11 to 1.0×10–4 mol/L. There was a good linear relationship between imidacloprid and imidacloprid, with a correlation coefficient of 0.9951. The limit of detection was 3.3×10–12mol/L, while the recoveries of Chinese cabbage samples were 91.86%–102.25%, with relative standard deviations of 1.98%–3.19%. Conclusion The sensor created in this study has excellent selectivity, repeatability, and stability. It is suitable for the rapid detection of imidacloprid in vegetables and provides a reference for the development of current agricultural residue rapid detection products.