Determination of mercury by anodic stripping voltammetry with a gold nanoparticle-modified glassy carbon electrode

The aim of this work is the development of a procedure for the determination of aqueous Hg(II) by anodic stripping voltammetry at a gold nanoparticle-modified glassy carbon electrode (AuNPs-GCE). The signal of aqueous Hg(II) was measured in the square wave mode; the effect of potential scan parameters, deposition potential and deposition time on the analytical signal was examined. The supporting electrolyte was 0.06 M HCl. The repeatability, the linearity, the accuracy, the detection limit of the procedure and the interferences of other cations and of anions were evaluated. The performance of the AuNPs-GCE was compared with those of a solid (SGE) and a film (FGE) gold electrode: the AuNPs-GCE showed to provide lower detection limits and higher repeatability. The renewable surface permits to eliminate memory effects, to maintain a stable baseline and response, and to avoid frequent mechanical cleaning steps. The applicability of the AuNPs-GCE for Hg(II) determination in drinking waters, sediments and pharmaceuticals was demonstrated.