Turn-on fluorescence detection of ascorbic acid with gold nanolcusters

In this report, a sensitive fluorescent detection of ascorbic acid was developed with protein-stabilized gold nanoclusters. The fluorescence signal from the gold nanoclusters could be effectively quenched by elemental iodine. This kind of quenching could be inhibited by ascorbic acid through a corresponding reduction process, thus a turn-on response toward ascorbic acid was obtained. The validity and performances of the detection scheme were evaluated. The fluorescence responses were linearly related to ascorbic acid in the concentration range 0.1-10 M, and the method was capable of detecting ascorbic acid down to 22 nM. The high performances of the developed scheme greatly simplified the sample preparation step, and the method was successfully applied for real sample analyses.