A promising electrochemical sensor based on gold deposited-reduced graphene oxide sheets for the detection of Cd(II) and Pb(II)

Abstract

This study presents electrochemical-based detection of heavy metal ions in mineral water samples. The aim of this research was to design a low-cost and highly sensitive disposable sensor to quantify Cd(II) and Pb(II). To this end, we have modified a pencil graphite electrode coated with graphene oxide (GO), electrochemically reduced graphene oxide and deposited metallic Au particles using square wave anodic stripping voltammetry. The findings revealed that the combined effect of GO and activation of the surface with auric acid improved electrical conductivity, thus facilitating deposition of Cd(II) and Pb(II) onto the electrode's surface. Under optimal conditions, a linear correlation was observed between current values and the concentrations of Cd(II) and Pb(II) within the ranges of 0.6-1.6 mu M and 0.4-1.6 mu M, where the limit of detection values were obtained as 0.36 mu M and 0.24 mu M for Cd(II) and Pb(II), respectively. According to the experimental results, the developed electrode can achieve a considerably high recovery rates for detection of Cd(II) (98.5%) and Pb(II) (93.5%) in gaseous natural mineral water samples.