A highly sensitive colorimetric chemodosimeter for cyanide anion by Michael addition based on a coumarin derivative

A colorimetric and fluorescent cyanide chemosensor L1 bearing a coumarin group has been designed and synthesized. It showed immediate visible color changes from yellow to colorless and blue fluorescence enhancement when CN- was added. The mechanism of the CN- anion recognition process was examined using H-1 NMR titration, FT-IR spectroscopy, ESI-MS and DFT calculations. The sensor was highly sensitive with a detection limit of 7.72 x 10(-8) M of CN-. Test strips based on the sensor L1 were fabricated, which could act as a convenient and efficient CN- test kit to detect CN- for in-the-field'' measurements.