Lysozyme-stabilized gold nanoclusters as a novel fluorescence probe for cyanide recognition.

Lysozyme-stabilized gold nanoclusters (Lys-AuNCs) have been synthesized and utilized as a fluorescent probe for selective detection of cyanide (CN(-)). Lys-AuNCs had an average size of 4 nm and showed a red emission at 650 nm (λex=370 nm). The fluorescence of Lys-AuNCs could be quenched by CN(-). An excellent sensitivity and selectivity toward the detection of CN(-) in aqueous solution was observed. The fluorescence intensity was linear with the CN(-) concentration in the range of 5.00×10(-6)M-1.20×10(-4) M with a detection limit as low as 1.9×10(-7) M. Also, the addition of CN(-) to Lys-AuNCs could induce an obvious color change from light yellow to colorless. Correspondingly, a bright red fluorescence disappeared and a blue fluorescence appeared. The results indicated that Lys-AuNCs could be applied in detection of cyanide on environmental aspects.