One-pot synthesis of an RGO/ZnO nanocomposite on zinc foil and its excellent performance for the nonenzymatic sensing of xanthine

A novel nonenzymatic xanthine (Xa) sensor was developed based on reduced graphene oxide (RGO)/zinc oxide (ZnO)/Zn foil. RGO/ZnO nanocomposites were grown directly on the surface of zinc foil through a hydrothermo-assisted redox reaction between graphene oxide (GO) and Zn foil. The as-synthesized RGO/ZnO/Zn foils were characterized through X-ray diffraction (XRD), Raman spectroscopy, and a field emission scanning electron microscope (FESEM), and the results confirmed that ZnO nanoparticles were dispersed highly inside RGO sheets. The RGO/ZnO/Zn foil was used directly as a xanthine electrochemical sensor, and its performance was evaluated through cyclic voltammetry and differential pulse voltammetry in a pH 7.0 phosphate buffer solution. This nonenzymatic biosensor showed a linear response to xanthine in concentrations ranging from 5 to 400 mu M, with a sensitivity of 2.10 mu A.mu M-1 cm(-2) and a detection limit of 1.67 mu M (S/N = 3). The present work supplies a new insight into the one-step preparation of graphene/metal oxide composite film on the conductive metal substrate and its application as an electrochemical sensor. (C) 2015 Elsevier B.V. All rights reserved.