Simultaneous Determination of Copper, Lead, and Cadmium Ions at a Mo6S9-xIx Nanowires Modified Glassy Carbon Electrode Using Differential Pulse Anodic Stripping Voltammetry

Abstract

A novel electrochemical sensor based on a new kind of nanomaterials Mo6S9-xIx nanowires modified glassy carbon electrode (GCE) was constructed for simultaneous determination of cadmium(II), lead(II) and copper(II) using differential pulse anodic stripping voltammetry (DPASV). Various experimental parameters such as the modified amount, pH, deposition time and deposition potential were optimized. Under the optimal conditions, the stripping peak currents increase linearly with increasing concentrations of Cd(II), Pb(II) and Cu(II) ions in the ranges of 0.5∼150 μg · L−1, 1.5∼450 μg · L−1 and 0.8～240 μg · μg·L−1, 1.5∼450 μg·L−1 and 0.8∼240 μg·L−1, respectively. And the limits of detection (S/N = 3) are estimated to be 0.10 μg · L−1 for Cd (II), 0.45 μg·L−1 for Pb(II) and 0.20 μg·L−1 for Cu(II), which are two orders of magnitude lower than those obtained at the unmodified electrodes. Most importantly, the sensor has been successfully applied to the determination of trace metal ions in the tap water samples. This developed electrochemical sensor exhibits high sensitivity, good stability and reproducibility.