New turn-on fluorescent and colorimetric probe for cyanide detection based on BODIPY-salicylaldehyde and its application in cell imaging.

Development of cyanide sensor is important as the anion is harmful to human health and the environment. Herein, a new colorimetric and fluorescent probe GSB based on boron dipyrrole-methene (BODIPY) containing salicylaldehyde group for cyanide detection has been reported. GSB undergoes exclusive colorimetric change from orange to colorless and exhibits selective fluorescence turn-on at 504nm upon the addition of cyanide. Other 13 anions give almost no interference under physiological condition. Detection limit of the new cyanide-sensing GSB is 0.88μM, which is below World Health Organization (WHO) recommended level in drinking water. A calculation by density functional theory (DFT) shows suppression of photoinduced electron transfer (PET) mechanism along with the interruption of π-conjugation between salicylaldehyde and BODIPY core by cyanide anion. Cell imaging studies demonstrated that GSB is compatible and capable of sensing cyanide anion in living cells.