Sensitive square wave anodic stripping voltammetric determination of Cd2+ and Pb2+ ions at Bi/Nafion/overoxidized 2-mercaptoethanesulfonate-tethered polypyrrole/glassy carbon electrode

Square wave anodic stripping voltammetry was applied to detect Pb2+ and Cd2+ ions at a glassy carbon electrode modified with overoxidized 2-mercaptoethanesulfonate (MES)-tethered polypyrrole, Nafion and Bi. The PPy–MES interaction was examined by quartz crystal microbalance. Under optimum conditions (5-min preconcentration at −1.2 V vs. SCE in pH 4.0 acetate buffer containing 300 μg L−1 Bi3+), the linear calibration curves ranged from 0.05 to 35 μg L−1 for Pb2+ and 0.1 to 25 μg L−1 for Cd2+, respectively, and the limits of detection (S/N = 3, S is the signal and N is the noise level) were 0.03 μg L−1 for Pb2+ and 0.04 μg L−1 for Cd2+. This method was successfully applied for Pb2+ and Cd2+ analysis in real water samples.