Highly selective and ultrasensitive detection ofHg2+ based on fluorescence quenching of Au nanoclusters by Hg2+–Au+ interactions

A simple label-free method for the detection of Hg2+ ions with high selectivity and sensitivity has been developed by using fluorescent Au NCs in aqueous media. The sensing mechanism was based on the high-affinity metallophilic Hg2+–Au+ interactions, which effectively quenched the fluorescence of Au NCs.