Preparation of imidacloprid imprinted electrochemical sensor and its electrical sensing mechanism

A novel molecularly imprinted membranes electrochemical sensor with good imprinted capacity to imidacloprid (IMI) was prepare by electrodeposition technique. Chitosan was deposited onto the surface of glassy carbon electrode as a functional monomer along with template molecules acetamiprid and glutaraldehyde as a crosslinking agent. Through cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), detection performance of the new sensor on imidacloprid was studied and the equivalent circuit model was constructed. The results showed that the new molecularly imprinted electrochemical sensor was prepared successfully; compared with the bare electrode, the sensor's apparent surface area was increased significantly; the imprinted effect of new sensors is good, and compared with other nicotine compound (e.g. acetamiprid) with the similar structure, IMI-MIP/F-CNTs/GCE exhibited a high effective and selective recognition ability for imidacloprid, and the quantitative relationship between the peak current of sensor and cIMI was existed at cIMI≤1×10-6 mol/L; the electrical impedance equivalent circuit model of sensor was R1(C1(R2(CPE2(R3)))) though data simulation analysis. The parameters of each element equivalent circuit proved that R1(C1(R2(CPE2(R3)))) equivalent circuit can effectively simulate the sensing mechanism of sensor when it detects the imidacloprid. The results of this work could provide a new analysis method of detecting the neonicotinoid pesticide and provide the reference for the detection pesticide mechanism by the sensors.