Electrochemical Hg2+ detection at tannic acid-gold nanoparticle modified electrodes by square wave voltammetry

Abstract

We report the electrochemical sensing of Hg²⁺ based on tannic acid capped gold nanoparticle (AuNP@TA) complexes. At optimal conditions using square wave voltammetry, the presented analytical method exhibits a “measurable lower limit” of 100.0 fM. This limit is considerably below the permissible level of 30.0 nM for inorganic mercury in drinking water, specified by the World Health Organization (WHO). The effect of potentially interfering ions, such as Zn²⁺ and Al³⁺, was studied and results indicate an excellent selectivity for Hg²⁺. The transfer of the proposed strategy onto AuNP@TA modified screen-printed electrodes demonstrates its applicability to routine monitoring of Hg²⁺ in tap water.