Rapid, selective, and sensitive fluorometric detection of cyanide anions in aqueous media by cyanine dyes with indolium–coumarin linkages

Cyanine dyes with indolium–coumarin linkages exhibit selective fluorescence enhancement for cyanide anions (CN−) via the nucleophilic interaction of CN− with their indolium carbon atoms. This facilitates rapid (detection time: 1 min) and sensitive (detection limit: 0.4 μM) sensing of CN− in aqueous media.