Electrochemical detection of mercury ions using glassy carbon electrode modified with silver sulphide nanoparticles

Abstract Mercury (Hg 2+ ) is a toxic heavy metal that can harm the environment and human health. This study introduces an innovative electrochemical sensor for the selective detection of Hg 2+ ions using square wave voltammetry (SWV). This research aims to develop a highly selective electrochemical sensor for detecting mercury ions by modifying a glassy carbon electrode (GCE) with silver sulphide (Ag 2 S) nanoparticles. The work intends to enhance the Ag 2 S modified GCE’s electroactive surface area and improve electron transport, leading to a more pronounced electrochemical response. The Ag 2 S crystalline structure was characterized by x-ray diffraction (XRD), while Transmission electron microscopy (TEM) confirmed spherical-shaped particles. Electrochemical impedance spectroscopy and cyclic voltammetry were employed to examine the electrochemical profile of the Ag 2 S nanoparticles, revealing an electroactive surface area of 9.93 cm 2 for the modified GCE. The SWV technique demonstrated effective detection of Hg 2+ ions with a detection limit of 0.14 nM. The designed sensor was found to demonstrate the qualities of selectivity, repeatability, reproducibility and anti-interference ability. The Ag 2 S modified GCE exhibited excellent stability and selectivity towards Hg 2+ ions in the presence of potential interferents such as Cu 2+ , Na + , Ca 2+ , and Zn 2+ . These results highlight the potential of the Ag 2 S nanoparticles modified GCE as a robust platform for environmental monitoring of mercury contamination.