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In this communication, we have developed an optical chemosensor 2-amino N-(6-bromo-1,3-dioxo-1H-benzo[ de ]isoquinolin-2(3H)-yl)benzamide ( NAPH ) for selective detection of Al 3+ by reacting 4-bromo-1,8-naphthalic anhydride with 2-aminobenzohydrazide. In (DMSO:H 2 O, 1:1, v/v) medium, the selective and specific nature of NAPH towards Al 3+ was observed by the quenching along with a blue-shift in the absorption of NAPH at 465 nm that resulted in the distinct colour change from light brown to colourless. The selective complexation that occurred between NAPH and Al 3+ was investigated by 1 H NMR and DFT methods. Under similar conditions, the weakly fluorescent receptor NAPH showed a distinct fluorescence enhancement at 555 nm in the presence of Al 3+ among the other tested metal ions and anions. The NAPH ·Al 3+ complex formation is reversible upon addition of strong chelating agent EDTA. The receptor NAPH can be applied to detect Al 3+ down to 2.9 μM without any interference from other tested metal ions. In addition, the receptor NAPH was successfully applied to detect Al 3+ in live HeLa cells. [ABSTRACT FROM AUTHOR]

A highly sensitive and selective coumarin based chemosensor H 2 L for the efficient detection of Al 3+ has been developed. The synthesized chemosensor H 2 L is efficient in detecting Al 3+ over other metal ions which are commonly obtained in various physiological and environmental samples. H 2 L shows fluorescence ‘turn-on’ response at 610 nm in presence of Al 3+ , without the interference of other metal ions. The resulting H 2 L-Al 3+ complex behave as a sequential chemosensor for F − , by showing quenching of emission intensity upon addition of F − to it. This quenching of emission intensity is only specific for F − and is not hampered due to the presence of other anions that commonly coexist with F − in various environmental solutions. Theoretical calculations using DFT/B3LYP method has been used to get insight into the sensing mechanism as well as electronic structure of the synthesized chemosensor H 2 L. H 2 L is efficient in detecting Al 3+ in the intracellular region of human A549 cell and also exhibits an INHIBIT logic gate with Al 3+ and F − as chemical inputs by monitoring the emission mode at 610 nm. [ABSTRACT FROM AUTHOR]