Selective Detection of Cyanide in Water and Biological Samples by an Off-the-Shelf Compound

The simple off-the-shelf chemical 6,7-dihydroxycoumarin (1) based copper complex (1 center dot Cu2+) has been used for the selective detection of toxic cyanide in aqueous medium. The DFT calculation confirms the binding behavior between 1 and Cu2+ (2:1) and the red shift in the UV-vis spectrum with copper ion was confirmed by the decrease in energy between HOMO-LUMO band gaps. The cyanide sensing in water was confirmed by both absorption and emission spectral studies. Cyanide ion showed 13-fold increments in fluorescent intensity in emission spectrum via displacement of copper from 1 center dot Cu2+. The limit of detection of CN- in water is 5.77 mu NM; 1 center dot Cu2+ also applicable for the detection of cyanide in fresh mouse serum with detection limit of 14.4 mu M. The cell images showed that 1 center dot Cu2+ could be used to detect intracellular CN-.