A water soluble fluorescent BODIPY dye with azathia-crown ether functionality for mercury chemosensing in environmental media

A novel mercury chemosensor based on water soluble fluorescent BODIPY probe 16 with an azathia-crown ether moiety has been synthesised through condensation of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene as a fluorophore coupled at the 3-position to an azathia macrocycle via an ethenylphenyl linker. Spectroscopic properties and complex formation with several metal ions are investigated in aqueous organic solvent and in water via colorimetric and fluorometric titrations. The binding ratio of chemosensor 16 to Hg2+ complex was determined to be 1 : 1 according to a Job plot. Hg2+ binding in chemosensor 16 was 8.19 × 103 M−1. The fluorescence and colorimetric spectroscopic experiments in this study demonstrated that chemosensor 16 can be used as a fluorescent and colorimetric probe for detecting Hg2+ in water.