A highly sensitive and selective electrochemical determination of Hg(ii) based on an electrochemically activated graphite modified screen-printed carbon electrode

Abstract

A highly sensitive and selective Hg(II) sensor based on an electrochemically activated graphite (EAG) modified screen-printed carbon electrode (SPCE) was developed. The fabricated EAG modified SPCE showed an enhanced current (I_pa) response towards Hg(II) relative to that of a graphite SPCE, an activated SPCE and a bare SPCE. Under optimum conditions, the EAG modified SPCE showed a wider linear range at Hg(II) concentrations of 0.05–14.77 ppm. The limit of detection was calculated to be 4.6 ppb with a sensitivity of 81.5 μA ppm⁻¹ cm⁻². The World Health Organization and the United States Environmental Protection Agency recommend maximum contaminant levels of Hg(II) in drinking water of 30 and 10 ppb, respectively. Therefore, the observed limit of detection (4.6 ppb) is considerably below these guideline values for Hg(II) in drinking water. In addition, the EAG modified SPCE exhibits a high selectivity for the electrochemical detection of Hg(II) in the presence of other heavy metal ions.