Dual-signaling fluorescent chemosensor based on bisthiazole derivatives

A new bisthiazole chemosensor (3) with phenolic substituents at the position 2 of the thiazole rings was prepared. The chemosensor 3 acts as a potential dual-function fluorescence chemosensor with Cu2+ and Zn2+ ions causing complete quenching and ratiometric change of fluorescence, respectively. The mechanism of fluorescence was based on the cation-induced inhibition of excited-state intramolecular proton transfer (ESIPT).