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

Abstract

The simple off-the-shelf chemical 6,7-dihydroxycoumarin ( 1 ) based copper complex ( 1·Cu 2+ ) has been used for the selective detection of toxic cyanide in aqueous medium. The DFT calculation confirms the binding behavior between 1 and Cu 2+ (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·Cu 2+ . The limit of detection of CN – in water is 5.77 μM; 1·Cu 2+ also applicable for the detection of cyanide in fresh mouse serum with detection limit of 14.4 μM. The cell images showed that 1·Cu 2+ could be used to detect intracellular CN – .