Efficient cobalt hydroxide nanosheets for enhanced electrochemical sensing of Hg (II) ion

Abstract

A sensitive electrochemical device was suggested via the modification of a simple graphite rod electrode (GRE) with cobalt hydroxide (Co(OH)2) nanosheets. After closed circuit process on the modified electrode, the anodic stripping voltammetry (ASV) technique was used for measuring of Hg(II). In optimal experimental conditions, the suggested assay depicted a linear response over a broad range in the range 0.25–30 μg L−1, with the lowest detection limit of 0.07 μg L−1. Besides good selectivity, the sensor also indicated excellent reproducibility with a relative standard deviation (RSD) value of 2.9%. Moreover, the Co(OH)2-GRE showed satisfactory sensing performance in real water samples with appropriate recovery values (96.0–102.5%). Additionally, possible interfering cations were examined, but no significant interference was found. By taking some merits such high sensitivity, remarkable selectivity and good precision, this strategy is expected to provide an efficient protocol for the electrochemical measuring of toxic Hg(II) in environmental matrices.