A new electrochemical sensor based on an Au-Pd/reduced graphene oxide nanocomposite for determination of Parathion

摘要

ABSTRACT In this paper, we introduce an easy method for the synthesis of bimetallic gold and palladium nanoparticles coated on reduced graphene oxide (Au-Pd/rGO nanocomposite). Also, the application of this nanocomposite for modification of carbon paste electrode (CPE) for electrochemical determination of Parathion (PAR) in aqueous solution is investigated. The synthesised Au-Pd/rGO was characterised using scanning electron microscope (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDS). The cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV) were employed to evaluate the electrochemical performance of the modified electrode toward PAR. The parameters which can affect the response of Au-Pd/rGO/CPE for determination of the analyte, such as pH, accumulation potential and time were optimised. The electrode represents a linear response at 0.01 to 11.2 µM and a detection limit of 0.008 µM under the optimised condition. The impact of some potential interfering species on the electrochemical determination of PAR were examined, and Au-Pd/rGO/CPE illustrates a good selectivity for determination of PAR. Finally, the modified electrode was applied to determine PAR in different spiked real samples with various matrixes including cucumber, cabbage, groundwater and tap water. The obtained results and the percentage of recoveries show an excellent capability of the proposed sensor for the detection of PAR in real samples.