Simultaneous Electrochemical Detection of Benzimidazole Fungicides Carbendazim and Thiabendazole Using a Novel Nanohybrid Material-Modified Electrode.

In this work, a novel ZnFe2O4/SWCNTs nanohybrid was successfully synthesized as electrode material and applied to the simultaneous quantitative determination of carbendazim (CBZ) and thiabendazole (TBZ). The electrochemical behaviors of CBZ and TBZ on the ZnFe2O4/SWCNTs/GCE were investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electrochemical active area of modified electrode was calculated, which is nearly 5.5 times that of the bare electrode. The influence of various factors such as accumulation time, pH and scan rates, type of surfactant, and the electrochemical reaction mechanism was studied. The results showed that the reaction of CBZ/TBZ was controlled by adsorption/diffusion and was a quasi-reversible/an irreversible process at the ZnFe2O4/SWCNTs/GCE. In the pH 7.0 phosphate-buffered saline (PBS) containing 10.0 μg/mL CTAB, the electrochemical responses of CBZ and TBZ were separately investigated and were linearly dependent on their concentrations ranging from 0.5 to 100.0 μM, with relatively low detection limits of 0.09 and 0.05 μM, respectively. The concentration range for the simultaneous determination of CBZ and TBZ was 1.0-100.0 μM. Furthermore, with satisfactory results, the proposed electrochemical sensor was successfully applied to the determination of CBZ and TBZ in the real samples.