Facile one-pot synthesis of L-proline-stabilized fluorescent gold nanoclusters and its application as sensing probes for serum iron.

Gold nanoclusters (Au NCs) possess outstanding physical and chemical attributes that make them excellent scaffolds for the construction of novel chemical and biological sensors. In this study, a simple one-pot synthesis method, employing l-proline as the stabilizer, was presented for preparation of fluorescent Au NCs. This strategy allowed the generation of water-soluble Au NCs within a short time of 15 min. The as-prepared Au NCs exhibited a bluish fluorescence emission at 440 nm and a quantum yield of 2.94%. Based on the aggregation-induced fluorescence quenching mechanism, the Au NCs provided favorable biocompatibility, high sensitivity and good selectivity for the measurement of ferric ion (Fe(3+)). Furthermore, serum samples were analyzed for the serum iron contents by using this proposed biocompatible fluorescent sensor, indicating the potential value of this Au NCs-based fluorescent sensor for application in biological and clinical analysis.