Chitosan-Stabilized Gold Nano Composite Modified Glassy Carbon Electrode for Electrochemical Sensing Trace Hg²⁺ in Practice

Abstract

A modified nano gold-based sensor, being stabilized on the substrate of polymer chitosan (chitosan-AuNPs), was developed for analyzing trace Hg2+ by cyclic voltammetry, which expected possessing excellent hydrophily, high dispersion, little aggregation and nice biological compatibility. By virtue of the predominant electro-chemical property of AuNPs combining with the strong chelating to Hg2+ of chitosan main chain, the proposed glassy carbon electrode modified by chitosan-AuNPs could exclusively sense Hg2+ using cyclic voltammetry by a mixed diffusion and adsorption-controlled process, accompanying with a good linear range of 1.0∼220.0 × 10−8 mol/L and a detection limit as low as 1.3 × 10−9 mol/L. What's more, it was successfully applied for detecting Hg2+ in environmental water samples and some fruit juices with excellent recovery between 96.2 and 105.8% and good R.S.D. ≤ 4.1%. The work offers a simple way to stabilize gold nano-based electro-chemical sensors for practical applications environment-friendly.