Silver Nanoparticle Modified Graphene Paste Electrode for the Electrochemical Detection of Lead, Cadmium and Copper

摘要

Silver nanoparticle (AgNP) graphene paste electrodes were fabricated from graphene powder mixedwith mineral oil and silver nanoparticles. Anodic stripping voltammetry (ASV) was utilized tosimultaneously detect lead (Pb2+), cadmium (Cd2+) and copper (Cu2+). The optimized amounts ofmineral oil and AgNP were 80μL and 2mg respectively. The calibration curve of the optimizedelectrode showed a strong line correlation between the heavy metal concentration and the reductioncurrent for Pb2+, Cd2+, and Cu2+. In addition, the limit of detection is 17 parts per billion (ppb) forCd2+, 12 ppb for Pb2+ and 44 ppb for Cu2+. The optimized electrode was tested on three commercialbrands of Puerh tea. Copper metal ions, Cu2+, were found in the tea samples. Lastly, atomic absorptionspectroscopy was used to verify the results obtained from ASV.