Differential pulse anodic stripping voltammetric determination of Pb ion at a montmorillonites/polyaniline nanocomposite modified glassy carbon electrode

In this paper, Na+–montmorillonites/polyaniline nanocomposite modified glassy carbon electrode (PANI/MMT/GCE) was prepared and characterized by scanning electron microscopy and electrochemical techniques. It was found that when PANI/MMT film was modified on the electrode, electrochemical responses could be improved significantly. The modified electrode could be applied in sensitive detection of Pb2+ by differential pulse anodic stripping voltammetry (DPASV). The 50 wt% feeding ratio of MMT to aniline of the nanocomposite exhibited the best electrochemical response to Pb2+. In 0.2 mol L−1 acetate buffer solution (pH 3.5), the stripping peak currents after enrichment at −1.20 V for 120 s showed good linear relationships with Pb2+ at concentration ranges of 4–100 nM with the correlation coefficient of 0.998, and the detection limit is 1 nM. The proposed method is applicable in the determination of trace Pb2+ in real water samples with the relative standard deviations less than 5.2% and the recovery rates of 94–103%.