A Simple and Highly Sensitive Electrochemically Reduced <i>p</i>‐Nitrobenzoic Acid Film Modified Sensor for Determination of Mercury

Abstract

Abstract Herein, a simple electrochemical sensor was fabricated for sensing Hg 2+ ions by using electrochemically reduced p ‐nitrobenzoic acid molecules modified (ERpNBA) glassy carbon electrode (GCE). The modified electrode was applied for the determination of Hg 2+ ions by using differential pulse anodic stripping voltammetry (DPASV). Experimental parameters such as concentration of p ‐nitrobenzoic acid used for electrode modification, pH, accumulation time and deposition potential used for the determination of Hg 2+ ions were optimized. The strong interaction between the Hg 2+ ions and the lone pair of electrons on the nitrogen atoms of ERpNBA molecules leads to highly selective adsorption of Hg 2+ ions on the modified electrode. Under the optimum experimental conditions, the sensor showed higher sensitivity and very low detection limit for Hg 2+ ions than other metal ions such as Cd 2+ , Pb 2+ and Zn 2+ ions. The LOD for Hg 2+ ions was 240 pM which is below the guideline value given by the World Health Organization and the earlier reports.