A novel quick and highly selective “turn-on” fluorescent probe for Hg2+ and its application

Abstract In the present work, we reported the simple synthetic strategy of fluorescent probe BAA . In order to increase the binding ability and selectivity of the probe for Hg 2+ , an alkynyl group was introduced on the adjacent position of the azo group of the probe. The molecular structure of BAA was characterized by 1 H NMR, 13 C NMR, IR, and MALDI-TOF. Spectrum analysis indicated that BAA exhibited high selective turn-on fluorescence signal and rapid response (about 10 s) to Hg 2+ . The selectivity can also be visualized under UV light, the BAA shows green fluorescence emission only in the presence of Hg 2+ . The stoichiometric ratio (1:1) between the probe and Hg 2+ could be obtained by the Job-plot and ESI-MS analysis, and was confirmed by quantum chemical calculations. The detection limit of Hg 2+ was 1.30 × 10 −7  M in aqueous media. We have demonstrated the suggested probe can detect Hg 2+ in lake water samples with satisfying results. Moreover, it exhibits excellent membrane permeability and has been successfully used for detection of Hg 2+ in MCF-7 living cells by confocal fluorescence imaging. The explored facile “turn-on” Hg 2+ fluorescent probe here may have the further potential applications in environmental testing, biomedicine and food analysis.