Switching to a "turn-on" fluorescent probe for selective monitoring of cyanide in food samples and living systems.

A fluorescent probe (TPA-BTD-MT) was designed to monitor cyanide ions (CN-) with a "turn-on" response, changing from "turn-off" behavior due to the structural change. TPA-BTD-MT exhibited high selectivity for sensing CN- in several food samples and was successfully used for imaging CN- in living cells and animals with strong "turn-on" fluorescence.