Colorimetrk Detection of Hg~(2+) Based on Enhancement of Peroxidase-like Activity of Chitosan-Gold Nanoparticles

摘要

Hg~(2+) is a serious environmental contaminant that can cause severe damage to the immune and nervous systems, and Hg~(2+) monitoring is critical. Herein, we report a novel, simple, and sensitive Hg~(2+) sensor based on the enhanced peroxidase-like activity of chitosan-gold nanoparticles (CS-AuNPs). The peroxidase-like activity of the CS-AuNPs can be markedly enhanced by Hg~(2+) as seen by the deeper color and increased absorbance at 652 nm. This improved catalytic ability was used to develop a sensitive and selective colorimetric sensor for Hg~(2+) detection. The limit of detection via the absorption spectra is as low as 0.02 uM. The mechanism underlying the enhanced catalytic ability is discussed. This approach is label-free, simple, and offers detection with the naked eye. Thus, it has potential applications for the detection of Hg~(2+) in environmental and food samples.