Synthesis of yeast extract-stabilized Cu nanoclusters for sensitive fluorescent detection of sulfide ions in water

In this work, we have presented a novel strategy to utilize as-synthesized yeast extract-stabilized Cu nanoclusters (Cu NCs) for sensitive and selective detection of S2−. The fluorescence intensity of Cu NCs was enhanced significantly in the presence of both Na2S2O8 and S2−. By virtue of this specific response, a Cu NC-based fluorescent turn-on sensor was developed, which allows the detection of S2− in the range of 0.02-0.8 μM with a detection limit of 10 nM. The enhancing mechanism was also discussed based on fluorescence decay, transmission electron microscopy (TEM) and dynamic light scattering (DLS) studies, indicating that S2− enhanced the Cu NCs emission mainly through sulfide-induced aggregation of Cu NCs. Furthermore, we demonstrated the usability of the present approach for the detection of S2− in water samples, which illustrates its great potential for the environmental monitoring and water quality inspection fields.