Highly selective fluorescent sensors for Hg(2+) 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 Hg(2+) 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 Hg(2+) over the ranges of 0.4-43.2 microM, 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) Hg(2+). Moreover, this method has excellent selectivity over metal ions and anions. The feasibility of the BSA-Au NCs sensor for Hg(2+) in different aqueous samples was demonstrated with satisfactory results. Moreover, the possible sensing Hg(2+) mechanism was also discussed.