Colloids and Surfaces A: Physicochem. Eng. Aspects 452 (2014) 39–45 Contents lists available at ScienceDirect Colloids and Surfaces A: Physicochemical and Engineering Aspects journa l h om epage: www.elsevier.com/locate/colsurfa Single step electrochemical fabrication of highly loaded palladium nanoparticles decorated chemically reduced graphene oxide and its electrocatalytic applications Muniyandi Rajkumar, Balamurugan Devadas, Shen-Ming Chen ∗ , Pin-Chun Yeh Electroanalysis and Bio electrochemistry Laboratory, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC h i g h l i g h t s • A highly loaded palladium nanopar- ticle on the chemically modified reduced graphene oxide (CRGO) has been prepared. • Simultaneous determination of dopamine and diclofenac. • Real sample application. • Sufficient enough peak separation around 0.43 V for DA and diclofenac. • The electrode possesses good sta- bility, reproducibility, sensitivity and wide linear range. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 21 December 2013 Accepted 19 March 2014 Available online 27 March 2014 Keywords: Chemically reduced graphene oxide Palladium nanoparticles Dopamine Diclofenac Simultaneous determination Electrochemistry a b s t r a c t 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 measure- ments 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 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 M. Furthermore, the proposed CRGO/Pd nanocomposite film modified electrode also retains the advantage of easy fabrication, high sensitivity, selectivity and good repeatability. © 2014 Elsevier B.V. All rights reserved. ∗ Corresponding author. Tel.: +886 2 27017147; fax: +886 2 27025238. E-mail address: smchen78@ms15.hinet.net (S.-M. Chen). 1. Introduction Graphene, a rising star in material science, chemistry, physics and nanotechnology has attracted enormous research interest since its unprecedented discovery and characterizations by man- ual mechanical cleavage from graphite using Scotch tape [1,2]. In http://dx.doi.org/10.1016/j.colsurfa.2014.03.058 0927-7757/© 2014 Elsevier B.V. All rights reserved.