Fluorescent Ag Clusters via a Protein-Directed Approach as a Hg(II) Ion Sensor

摘要

ABSTRACT: Proteins have proven to be particularly attractivenas effective ligands in the synthesis of nano- and subnanoscalednmaterials because of their multiple chelating and functionalngroups imparting unique functionalities. However, protein-ndirected fluorescent metal cluster synthesis is still a challengenbut a promising area of research. Here, we report on thensynthesis of new water-soluble, stable, fluorescent Ag clustersnvia a facile, green method using denatured bovine serumnalbumin (dBSA) as a stabilizing agent. The dBSA with its 35nfree cysteine residues could contribute to polyvalent interac-ntions with the Ag clusters and serve as effective stabilizing agentsnfor these clusters. The as-prepared Ag clusters showed high fluorescence emission at ∼637 nm and were stable even in 1 M NaCl.nThe fluorescent Ag clusters were then used in the detection of Hgn2þ with high sensitivity and selectivity. The detection limit wasn10 nM in the linear range from 10 nM to 5 μM.