Determination of copper(II) and cadmium(II) in rice samples by anodic stripping square wave voltammetry using reduced graphene oxide/polypyrrole composite modified screen-printed carbon electrode

Abstract

© 2019, Chiang Mai University. All rights reserved. In this work, a polypyrrole (PPy)/reduced graphene oxide (rGO) composite has been used to develop an electrochemical sensor for quantification of trace Cu(II) and Cd(II) in rice samples via square-wave anodic stripping voltammetry (SWASV). To fabricate the sensor, PPy/rGO was deposited on a screen-printed carbon electrode (SPCE) by simple drop casting. The detection of such two heavy metals by SWASV method was achieved by optimizing some parameters such as materials composition, pH of electrolyte, the deposition time and the deposition potential. As a result, the modified electrode with PPy/rGO nanocompsite exhibited reproducible response, high sensitivity and good stability for Cd(II) and Cu(II) ions. Under optimal conditions, it provided high sensitivity, wide linear ranges (0.10 to 500.0 µgL-1 and 500 to 5000 mgL-1) with low detection limits (for Cu(II) 0.064 µgL-1 and for Cd(II) 0.097 µgL-1), and had excellent repeatability and good recoveries (94% to 117%). This proposed PPy/rGO sensor was used to the determination of copper and cadmium in rice samples.