Bio-inspired green fluorescent gold-naringin nanoclusters as a dual-functional optical probe for bio-imaging and intracellular sensing applications

Human exposure to mercury (Hg2+) happens in everyday life via exposure to aquatic animals like fishes, shrimps, and prawns. We developed bio-inspired gold-naringin nanoclusters (GNNCs) as a novel fluorescent probe for sensitive and selective detection of Hg2+ ions. GNNCs exhibit green-color emission under UV illumination with excellent selectivity for Hg2+ over other metal ions. GNNCs demonstrated excellent photostability and excitation-dependent emission behaviors. As-synthesized GNNCs facilitate Hg2+ detection in the range of 0-5 mu M with a detection limit of 26.42 nM. GNNCs also provide effective multi-color fluorescence imaging of shrimp as an animal model. GNNCs displayed excellent intracellular fluorescence sensing of Hg(2+ )and in vitro cytotoxicity in cancer (A549) cells. The practicality and feasibility of GNNCs were examined using real water samples from streams and tap water.