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

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 mu M. 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.