Simple Michael acceptor type coumarin derived turn-on fluorescence probes to detect cyanide in pure water

The present article describes design and synthesis of coumarin derived chemical reaction based chemodosimeter to recognize cyanide in aqueous medium. The Michael acceptor type coumarin derived probes 3 and 4 upon interaction with cyanide undergo Michael type nucleophilic addition reaction to form adducts in which fluorescence intensity was significantly enhanced, 'turn-on' by the change in intramolecular charge transfer (ICT) mechanism. The nonfluorescent color of solutions changed to a naked-eye sensitive fluorescent blue (switched-on). Job's plot analysis revealed a 1:1 stoichiometry for the interaction between the probe and cyanide anion with a high detection limit.