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

[Display omitted] •Hg2+-induced excimer of a naphthalene-based fluorescent probe (BNBC) was developed.•BNBC allows a selective and sensitive ratiometric detection of Hg2+ without any interference from other metal ions.•BNBC-Hg2+ complex shows a selective detection of I– via the formation of three-component ensemble. A small-molecule fluorescent probe (BNBC) based on naphthalene for cascade recognition of Hg2+ and I– in 50% CH3CN/H2O 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 Hg2+, which was attributed to the excimer-monomer emissions of naphthalene. Moreover, the BNBC-Hg2+ complex showed a selective fluorescence “turn-off” for I– via the formation of three-component ensemble.