Graphene –modified carbon paste electrode for cadmium and lead monitoring with flow based system

摘要

The first report of green-electrode sensor in flow automated system was successful to determine Cd~(2+) and Pb~(2+) . The electrochemical methods including cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV) were employed to study the electrochemical behavior at graphene– modified carbon paste electrode. Furthermore, in-situ bismuth film deposited on graphene–modified carbon paste electrode was used to prevent the effect of oxygen in the solution. The bismuth-graphene carbon paste electrode (Bi-GCPE) exhibited the excellent electrooxidation of Cd~(2+) and Pb~(2+) in automated flow system. The peak current of Cd~(2+) and Pb~(2+) significantly increased when compared with those at unmodified with graphene. The detection limit (LOD) of 0.07 and 0.04 μg L~(-1) were obtained for Cd~(2+) and Pb~(2+), respectively. The oxidation peak current of Cd~(2+) and Pb~(2+) showed a linear relation in the range from 0.10 to 50.0 μg L~(-1) under the optimum condition. The Bi-GCPE electrode was applied for the determination of Cd~(2+) and Pb~(2+) in tap water sample