A Turn‐On Fluorescence Probe Based on GSH‐Protected Silver Nanoclusters for the Selective Detection of Pb2+

ABSTRACT Glutathione‐protected silver nanoclusters (GSH‐AgNCs) with good photostability were successfully synthesized through a one‐pot heating process. The resultant GSH‐AgNCs with an average diameter of ~1.6 nm exhibit red fluorescence (λ em = 650 nm), and the fluorescence is excitation independent. Strong aggregation‐induced emission (AIE) effect was observed in GSH‐AgNCs, which can be induced by solvent and metal ions. In particular, a specific fluorescence enhancement was detected upon interaction with lead ions (Pb 2+ ). A fluorescent probe was designed for off–on detection of Pb 2+ based on as‐synthesized GSH‐AgNCs. Under the optimum parameters, two linear response intervals were found between the relative fluorescence intensity and the concentration of Pb 2+ in the range of 10–250 μM ( R 2 = 0.9900) and 400–1000 μM ( R 2 = 0.9930). Significant fluorescence color evolutions observed under UV light, resulting in a semiquantitative visual detection of Pb 2+ . A possible detection mechanism based on the interaction between GSH‐AgNCs and Pb 2+ is discussed.