Preparation of tebuconazole imprinted electrochemical sensor and analysis of the electrical mechanism of its residuing detection

A new molecularly imprinted membranes-based electrochemical sensor with high imprinted capacity to tebuconazole(TEB) was prepared by electrochemical polymerization. Methacrylic acid was deposited onto the surface of glassy carbon electrode as a functional monomer along with template molecules TEB, and ethylene glycol dimethacrylate as a crosslinking agent. Through cyclic voltammetry(CV), differential pulse voltammetry(DPV) and electrochemical impedance spectroscopy(EIS), detection performance of the new sensor on tebuconazole was evaluated and the equivalent circuit model was constructed. The results showed that the new molecularly imprinted electrochemical sensor was prepared successfully with high specificity. Compared with the bare electrode, the sensor's apparent surface area was increased significantly, and the imprinted effect of new sensors is good. Compared with other triazole compound(e.g. difenoconazole) with the similar structure, TEB-MIP/F-CNTs/GCE exhibited high effective and selective recognition ability for TEB. The quantitative relationship between the peak current of sensor and cTEB was built at cTEB ≤ 2.0×10-6 mol/L; the electrical impedance equivalent circuit model of sensor was R1(CPE1(R2(CPE2(R3)))) through data simulation analysis. The parameters of each element equivalent circuit suggested that R1(CPE1(R2(CPE2(R3)))) equivalent circuit could effectively simulate the sensing mechanism of sensor when analyzing TEB. The results of this work provided basic information for developing a bionic immunoassay method of detecting triazole pesticide residues.