Electrochemical Hg2+ sensor based on electrospun cellulose acetate nanofibers doped with Ag nanoparticles

Abstract

Mercury (Hg) sensors are critical for environmental monitoring, industrial processes, and public health. They are designed to measure the presence and concentration of mercury ions (Hg2+) in various matrices, including air, water, soil, and biological samples. Mercury in the environment raises concerns due to its toxicity and potential for bioaccumulation. Therefore, this work aims to develop an improved, eco-friendly mercury sensor to address the evolving need for monitoring and control of mercury. The electrochemical sensor for reported here is based on the ability of silver (Ag) to catalyze the reduction of the mercury species Hg2+ to elemental mercury (Hg0), forming an Ag/Hg amalgam. To optimize this sensor, the concentration of silver nanoparticles (AgNPs) on modified nanofibers is determined using differential pulse voltammetry (DPV). Morphological studies and chemical characterization reveal a fiber thickness ranging from 250 to 450 nm and characteristic functional groups, respectively. The sensoŕs analytical performance for detecting Hg2+ concentrations is evaluated through cyclic voltammetry (CV) and DPV in 0.1 M potassium chloride as a supporting electrolyte. The sensor’s detection limit (LOD) for Hg2+ was 0.43 μg/L, with a sensitivity of 0.33 mA/μg/L. In conclusion, the electrochemical sensor exhibits sensitivity and selectivity for Hg2+ detection in the presence of other interfering metal ions, along with eco-friendly and cost-effective features, making it a reliable and practical tool for detecting Hg2+ concentration in water samples.