Electrochemical investigation of methyl parathion at gold–sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode

A gold/sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode (nano-Au/SDBS/GCE) was electrochemically fabricated with a constant potential at −0.4 V. The obtained nano-Au/SDBS/GCE was characterized with scanning electronic microscopy, X-ray photoelectron spectroscopy and electrochemical techniques. Electrochemical behaviors of methyl parathion at the nano-Au/SDBS/GCE were thoroughly investigated. Compared to the unmodified electrode, the peak current obviously increased and the oxidation peak potential negatively shifted. These changes indicated that the composite nanoparticles possess good electrocatalytic performance on the electrochemical reaction of methyl parathion. Experimental parameters such as deposition time, pH value and accumulation conditions were optimized. Under optimum conditions, the peak current corresponding to the oxidation of the hydroxylamine group was found in a good linear relationship with the methyl parathion concentration. In addition, a calibration curve with excellent linearity was obtained in the concentration range from 5.0 × 10−7 mol L−1 to 1.0 × 10−4 mol L−1 with an estimated detection limit of 8.6 × 10−8 mol L−1 (S/N = 3). The successful determination of methyl parathion in real samples demonstrated the usefulness and potential applications of this method.