Lysozyme-stabilized bimetallic gold/silver nanoclusters as a turn-on fluorescent probe for determination of ascorbic acid and acid phosphatase

Abstract

Bimetallic gold/silver nanoclusters were synthesized in aqueous solution with lysozyme as a stabilizing and reducing agent. The prepared lysozyme-stabilized gold/silver nanoclusters (Lys-Au/Ag NCs) displayed highly near-infrared fluorescence and excellent stability under various pH values and ionic environments. We found that ascorbic acid (AA) significantly enhanced the fluorescence of Lys-Au/Ag NCs and L-ascorbyl-2-phosphate (PAA) had little effect on the fluorescence of Lys-Au/Ag NCs. Under acidic conditions, acid phosphatase (ACP) can catalyze the hydrolysis of PAA to generate AA molecules, enhancing the fluorescence of Lys-Au/Ag NCs. Therefore, we utilized the novel Lys-Au/Ag NCs as a turn-on fluorescent probe for the simple and convenient determination of ACP in the presence of PAA molecules.