Coumarin-Cu(II) Ensemble-Based Cyanide Sensing Chemodosimeter

An “ensemble”-based chemodosimeter <b>1</b>–Cu(II) for cyanide detection is reported. 1–Cu(II) can recognize a cyanide ion over other anionic species to show a marked fluorescence enhancement under aqueous conditions. “Off–on” fluorescence change of <b>1</b>–Cu(II) is proceeded by addition of cyanide, which induces decomplexation of the Cu(II) ion from nonfluorescent <b>1</b> followed by hydrolytic cleavage of the resulted Schiff base to give a strongly fluorescent coumarinaldehyde (<b>2</b>). The selective detection of cyanide with <b>1</b>–Cu(II) for biological application was also performed in HepG2 cells.