Hg2+-induced excimer of a naphthalene-based fluorescent probe for recognition I–

A small-molecule fluorescent probe ( BNBC ) based on naphthalene for cascade recognition of Hg 2+ and I – in 50% CH 3 CN/H 2 O solution. The sensitive and selective binding behaviors of BNBC were investigated by fluorescence spectroscopy. With the addition of metal ions , the fluorescent probe BNBC showed high sensitivity and selective ratiometric detection of Hg 2+ , which was attributed to the excimer-monomer emissions of naphthalene . Moreover, the BNBC -Hg 2+ complex showed a selective fluorescence “turn-off” for I – via the formation of three-component ensemble.