Highly selective fluorescent sensors for Hg2+ based on bovine serum albumin-capped gold nanoclusters

In this paper, we report a new homogeneous assay for rapid, highly selective and sensitive detection of Hg2+ in aqueous solution based on the induced photoluminescence (PL) quenching of BSA-modified gold nanoclusters (BSA-Au NCs). There was a linear correlation between the expression (I-0 - I)/I-0 and the concentrations of Hg2+ over the ranges of 0.4-43.2 mu M, and the corresponding limit of detection (LOD) was 80 nM. The relative standard deviation of 5 replicate measurements was 1.4% for 1.0 x 10(-5) mol L-1 Hg2+. Moreover, this method has excellent selectivity over metal ions and anions. The feasibility of the BSA-Au NCs sensor for Hg2+ in different aqueous samples was demonstrated with satisfactory results. Moreover, the possible sensing Hg2+ mechanism was also discussed.