A probe based on 2-(2'-hydroxyphenyl) benzothiazole (HBT) and thiophosphate has been synthesized and used for the ratiometric detection of Hg(2+). The probe was designed in such a way that the excited state intramolecular proton transfer (ESIPT) of the HBT moiety get blocked. The probe exhibited a strong fluorescence enhancement upon addition of Hg(2+) while showing almost no response to other cations in CH3CN/HEPES buffer solution. The probe exhibited fast selectivity towards Hg(2+) and could be completed in 1 min. Fluorescence imaging experiments of Hg(2+) in living TE-1 cells demonstrated its value of practical applications in biological systems.
Keywords: Deprotection; ESIPT; Fluorescence; Hg2+; Thiophosphate.