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

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-2 H -chromene-3-carbohydrazide ( CHS ) was synthesized for sequential detection of Al 3+ and pyrophosphate ions (PPi) in a DMSO/HEPES (4:1 v/v, pH = 7.4) buffer system and characterized by 1 H NMR, 13 C NMR, ESI-HR-MS and DFT calculation. Its detection limit was determined to be 0.16 μM for Al 3+ and 0.18 μM for PPi in a pH range of 4∼8, respectively. The Job’ s plot showed that the stoichiometric ratio to Al 3+ was 1:1, and CHS -Al 3+ showed highly selective recognition of PPi. The sensor CHS could also recognize Al 3+ and PPi and exhibited fluorescence enhancement and quenching properties in HeLa cells.