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以壳聚糖为功能基体、吡虫啉(imidacloprid,IMI)为模板分子、戊二醛为交联剂,应用恒电位沉积法制备了分子印迹电极并构建了吡虫啉印迹传感器(IMI-MIP/F-CNTs/GCE)。利用循环伏安法(cyclic voltammetry,CV)、差分脉冲伏安法(differential pulse voltammetry,DPV)及交流阻抗法(electrochemical impedance spectroscopy,EIS)考察了新型传感器对吡虫啉的检测性能并构建等效电路模型。结果表明:成功制备了新型分子印迹电化学传感器;传感器表观表面积比裸电极显著提高;新型传感器具有良好的印迹效果,相较于其他结构类似的烟碱化合物(如啶虫脒等),IMIMIP/F-CNTs/GCE对吡虫啉表现出高效的选择识别能力,且在cI M I≤1.0×10-6mol/L范围内传感器峰电流与cI M I存在定量关系;数据模拟分析获得传感器电学阻抗谱等效电路模型为R1(C1(R2(CPE2(R3)))),计算等效电路各元件参数证明该模型能有效模拟传感器检测吡虫啉的传感机理。所得结果可为烟碱类农药残留检测提供一种新的分析方法,为农药残留检测传感器分析机理研究提供有益参考。
IMI-MIP / F-CNTs (IMI-MIP / F-CNTs) were prepared by potentiostatic deposition using chitosan as substrate, imidacloprid (IMI) as template and glutaraldehyde as crosslinking agent / GCE). The detection performance of imidacloprid was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS), and the equivalent circuit model . The results showed that a new type of molecularly imprinted electrochemical sensor was successfully prepared. The apparent surface area of the sensor was significantly higher than that of the bare electrode. The new sensor had a good imprinting effect. Compared with other nicotinic compounds of similar structure (such as acetamiprid), IMIMIP / F-CNTs / GCE showed a high selectivity for imidacloprid selection, and there was a quantitative relationship between the peak current of the sensor and the cI MI in the range of cI MI≤1.0 × 10-6mol / L. The data obtained by the simulation of the electrical impedance spectroscopy The circuit model is R1 (C1 (R2 (CPE2 (R3)))). Calculating the parameters of the equivalent circuit components proves that the model can effectively simulate the sensor sensing mechanism of imidacloprid detection. The results can provide a new analytical method for the detection of nicotine pesticide residues and provide useful reference for the analysis of pesticide residue detection sensors.