Simultaneous determination of trace Cd(II) and Pb(II) based on Bi/Nafion/reduced graphene oxide-gold nanoparticle nanocomposite film-modified glassy carbon electrode by one-step electrodeposition

Abstract

In this paper, a simple and controllable one-step electrodeposition method was used to fabricate a novel reduced graphene oxide-gold nanoparticles (RGO-GNPs) nanocomposite film onto the surface of bare glass carbon electrode (GCE), and then, Nafion was modified onto the film to prepare an electrochemical sensor for simultaneous detection of trace Cd(II) and Pb(II) in square-wave anodic stripping voltammetry (SWASV) with situ plating bismuth film. The morphologies and electrochemistry properties of the modified electrode were characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), cyclic voltammetry (CV), and SWASV. It was found that the formed RGO-GNPs nanocomposite film on the GCE surface could remarkably facilitate the electron transfer and enlarge the specific surface area of the electrode. While the Nafion film could effectively increase the adhesion and stability of RGO-GNPs nanocomposite layer, enhance cation-exchange capacity, and prevent the macromolecule in real samples absorbing on the surface of electrode. The Bi/Nafion/RGO-GNPs/GCE demonstrated a highly linear behavior in the simultaneous detection of Cd(II) and Pb(II) in the concentration range of 1.0 to 90 μg/L with detection limits of 0.08 and 0.12 μg/L (S/N = 3), respectively. Finally, The developed electrode was further applied to the determination of Cd(II) and Pb(II) in soil samples with satisfactory results.