Azo dye-based latent colorimetric chemodosimeter for the selective detection of cyanides in aqueous buffer

We report a novel latent colorimetric probe (1) for cyanide, which possesses a masked phenol in the para position of an azo dye group. Upon the addition of cyanides, probe 1 undergoes a ring opening reaction through the Michael addition of cyanide ion and a subsequent [1,3]-sigmatropic rearrangement reaction to give rise to a stable free phenol, whose signal is transduced to the azo dye unit producing a dramatic color change.