A novel schiff base fluorescent probe based on coumarin and benzothiazole for sequential detection of Al3+ and PPi and its applicability in live cell imaging

Abstract In this study, a novel schiff base fluorescent probe (E)-N'-(3-(benzo[d]thiazol-2-yl)-2-hydroxy-5-methylbenzylidene)-7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide (CHS) was synthesized for sequential detection of Al3+ and pyrophosphate ions (PPi) in a DMSO/HEPES (4:1 v/v, pH = 7.4) buffer system and characterized by 1H NMR, 13C NMR, ESI-HR-MS and DFT calculation. Its detection limit was determined to be 0.16 μM for Al3+ and 0.18 μM for PPi in a pH range of 4-8, respectively. The Job’ s plot showed that the stoichiometric ratio to Al3+ was 1:1, and CHS-Al3+ showed highly selective recognition of PPi. The sensor CHS could also recognize Al3+ and PPi and exhibited fluorescence enhancement and quenching properties in HeLa cells.