A new triphenylamine fluorescent dye for sensing of cyanide anion in living cell

A triphenylamine-based fluorescent probe 1 with larger Stokes shift (∼141 nm) has been synthesized, which can make an efficient nucleophilic addition by reacting with CN− in water. Upon addition of CN−, the red fluorescence of 1 was distinctly quenched. Importantly, 1 exhibits a highly selective response toward CN− over other anions in water and a high sensitivity (detection limit ⩽ 11 nM). Moreover, it has potential application to track CN− levels in living cells by confocal laser scanning microscopy (CLSM).