Al3+ selective coumarin based reversible chemosensor: application in living cell imaging and as integrated molecular logic gate

Abstract

An efficient coumarin based fluorescent ‘turn-on’ receptor (H₂L) for the detection of Al³⁺ has been synthesized following simple Schiff base condensation of 4-hydroxy-3-acetylcoumarin with 2-amino-4-methylphenol. The receptor H₂L shows about 21 fold increase in fluorescence intensity upon addition of Al³⁺ than in the case of other metals. The limit of detection is 0.39 μM. H₂L is efficient in detecting Al³⁺ in the intracellular region of human cervical cancer cells and also exhibits an INHIBIT logic gate with Al³⁺ and EDTA as chemical inputs by monitoring both the absorption as well as emission mode. Theoretical calculations (DFT and TDDFT) are applied to interpret the sensing mechanism of the synthesized receptor.