A fluorescent probe based on aptamer gold nanoclusters for rapid detection of mercury ions

Mercuric ion (Hg 2+ ) is a hazardous pollutant widely exist in living organisms, foods and environments with highly toxic and bio-accumulative properties. In this work, a fluorescent probe based on aptamer gold nanoclusters (apt-AuNCs) was prepared for ultrasensitive detection of Hg 2+ in food. The fluorescence of apt-AuNCs was quenched in the presence of Hg 2+ due to the strong metallophilic interactions between the 5d 10 centers of Hg 2+ and Au + . Under optimal conditions, the proposed fluorescent probe displayed a linear relationship with Hg 2+ concentration in the range of 2~ 200 nM (R 2 =0.9960), the limit of detection (LOD) at 0.0158 nM, which is below the national standard value of 25 nM for Hg 2+ in food. Furthermore, the apt-AuNCs can be applied for the determination of Hg 2+ in real food samples, with recoveries of 91.99% ~ 108.06%.