Highly-sensitive Electrochemical Sensor for Cd2+ and Pb2+ Based on the Synergistic Enhancement of Exfoliated Graphene Nanosheets and Bismuth

Graphene nanosheets (GS) were prepared via ultrasonic exfoliation, and used to modify glass carbon electrode (GCE). Compared with GCE, the GS-modified GCE (GS/GCE) greatly increased the anodic stripping peak currents of Cd 2+ and Pb 2+ . Moreover, the response signals of Cd 2+ and Pb 2+ on GS/GCE further enhanced remarkably in the presence of Bi 3+ . Based on the synergistic enhancement effects of GS and Bi 3+ , a novel electrochemical sensor was developed for Cd 2+ and Pb 2+ . The detection limits were 0.35 and 0.045 μg L −1 for Cd 2+ and Pb 2+ . It was used in food sample analysis, and the accuracy was tested by ICP-MS.