Voltammetric Detection of Diazinon Insecticide at Ferrocene-Graphene/Nafion Modified Glassy Carbon Electrode

In this study, ferrocene was used to modify a glassy carbon electrode, which was fixed with an appropriate amount of nafion solution. The -C-O-C- and -COOH functional groups were detected in the ferrocene/graphene composite, which indicated that graphene was oxidized to graphene oxide, making it more hydrophilic, dispersible and compatible with polymers, thus increasing the diazinon detection rate. The optimal conditions for diazinon detection were found using cyclic voltammetry (CV): a scan rate of 50 mV/s, pH 6.6, and 0.1 mol/L PBS buffer solution. Differential pulse voltammetry (DPV) shows that the concentrations of diazinon are 1×10-6 – 1.2×10-5 mol/L, and there is a good linear relationship between the peak current and the concentration: Ipa (μA)=2.0578 c(μM) -38.2518, R2 = 0.9971; the detection limit is 1.2×10-9 mol/L. This modified electrode has good stability, repeatability and operability and can be applied to detect actual samples.