A near-infrared BODIPY-based fluorescent probe for ratiometric and discriminative detection of Hg and Cu ions in living cells.

A near-infrared distyryl boron dipyrromethene-based sensor bearing one bis(1,2,3-triazole)amino receptor has been synthesized. This probe selectively and quickly binds to Hg and Cu ions in CHCN/HO (5:1 v/v) and exhibits remarkably blue-shifted absorption and fluorescence bands due to the inhibition of the intramolecular charge transfer process. The fluorescence changes of this probe upon binding to Hg or Cu ion are totally different, undergoing a ratiometric fluorescence enhancement (for Hg) or a fluorescence quenching (for Cu) mechanism. The corresponding vivid color changes can be easily seen by the naked eye. This probe was further introduced into Hela cells for living cell imaging and found to discriminate Hg and Cu ions through two near-infrared fluorescence emission channels. These overall results indicate that this Click-derived near-infrared BODIPY-based probe is potentially useful for ratiometric and discriminative detection of Hg and Cu ions in solutions and living cells.