Application of gold nanoparticles/polyaniline-multi-walled carbon nanotubes modified screen-printed carbon electrode for electrochemical sensing of zinc, lead, and copper

In this work, we report a simple, disposable, and highly sensitive electrochemical sensor based on a screen-printed carbon electrode (SPCE) modified with gold nanoparticles/polyaniline-multi-walled carbon nanotubes composite (AuNPs/PANI-MWCNTs) for simultaneous detection of zinc (Zn(II)), lead (Pb(II)), and copper (Cu(II)) by square wave anodic stripping voltammetry (SWASV). The proposed sensor exhibited three pronounced and independent peaks for Zn(II), Pb(II), and Cu(II) and showed wide linear ranges from 1 to180 μg L−1 for each. The detection limits (S/N = 3) of Zn(II), Pb(II), and Cu(II) were 0.039 μg L−1, 0.037 μg L−1, and 0.017 μg L−1, respectively, which are lower than the minimum values set by the Environmental Protection Agency (EPA) for drinking water. Besides, the proposed sensor exhibited excellent repeatability, reproducibility, stability, and selectivity. Finally, the feasibility of our analysis method was verified by the determination of trace Zn(II), Pb(II), and Cu(II) in water samples, and the obtained results were consistent with the ICP-MS determination.