▎ 摘　　要

A facile electrochemical approach has been developed for the synthesis of Palladium (Pd) nanoparticles decorated chemically reduced graphene oxide (CRGO) sheets on glassy carbon electrode (GCE) and indium tin oxide (ITO) electrodes by simple electrochemical deposition process. The electrochemical measurements and surface morphology of the as prepared nanocomposite electrode were studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) analysis. The amount of CRGO loading was optimized by EIS analysis. The presence of CRGO in the film enhances the surface coverage concentration and also increases the electron transfer rate constant of the Pd nanoparticles. The palladium nanoparticles successfully decorated on CRGO modified electrode (CRGO/Pd) and it exhibits a noticeable electrocatalytic activity towards the simultaneous detection of dopamine (DA) and diclofenac in pH 7 PBS solution. Exclusively, the proposed CRGO/Pd nanocomposite film modified GCE successfully and showed two well separated anodic oxidation peaks for the detection of DA and diclofenac in mixture solutions with a linear range of 2-63 mu M. The film was also successfully used for the simultaneous detection of DA and diclofenac in real samples with a linear range of 2-50 mu M. Furthermore, the proposed CRGO/Pd nanocomposite film modified electrode also retains the advantage of easy fabrication, high sensitivity, selectivity and good repeatability. (C) 2014 Elsevier B.V. All rights reserved.