Improving the Voltammetric Determination of Hg(II): A Comparison Between Ligand-Modified Glassy Carbon and Electrochemically Reduced Graphene Oxide Electrodes

Sensitive and selective determination of trace amounts of mercury ions using a dimercaprol functionalized graphene quantum dot modified glassy carbon electrode

A novel nanomaterial is synthesized based on the functionalization of graphene quantum dot with dimercaprol (GQD-DMC). Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (TEM) are used to approve the successful synthesis of GQD-DMC. The synthesized nanomaterial is used as an electrode modifier for the sensitive and selective determination of mercury(ii) ions in real water samples. The method of evaluation is based on the pre-concentration of mercury ions on the GQD-DMC modified glassy carbon electrode, reduction of Hg(ii), and anodic stripping voltammetric measurement of these reduced ions in a buffer solution. The pre-concentration of mercury ions is driven by the affinity interaction between the surface containing functional groups of DMC and Hg(ii) ions. The GQD-DMC modified glassy carbon electrode (GQD-DMC/GCE) shows extra sensitivity and selectivity for mercury(ii) detection, which is assumed to be due to the increased surface area as well as the presence of sulfur-containing functional groups on the modified structure.