Highly Sensitive, Colorimetric Detection of Mercury(II) in Aqueous Media by Quaternary Ammonium Group-Capped Gold Nanoparticles at Room Temperature

摘要

We provide a highly sensitive and selective assay to detectnHg2+ in aqueous solutions using gold nanoparticlesnmodified with quaternary ammonium group-terminatednthiols at room temperature. The mechanism isnthe abstraction of thiols by Hg2+ that led to thenaggregation of nanoparticles. With the assistance ofnsolar light irradiation, the detection limit can be as lownas 30 nM, which satisfies the guideline concentrationnof Hg2+ in drinking water set by the WHO. In addition,nthe dynamic range of detection is wide (3 × 10-8-1 ×n10-2 M). This range, to our best knowledge, is thenwidest one that has been reported so far in goldnnanoparticle (AuNP)-based assays for Hg2+.