A visible light excitable chromone appended hydrazide chemosensor for sequential sensing of Al+3 and F− in aqueous medium and in Vero cells.

A probe, quinoline-2-carboxylic acid (4-oxo-4H-chromen-3-ylmethylene)-hydrazide, (HL), acts as selective and specific fluorogenic sensor to Al +3 in the visible light (435 nm) excitation in presence of biologically available large number of cations and emission appears at (λ em ) 520 nm. The limit of detection (LOD) for Al +3 is 7.6 nM in aqueous medium which is less than 10 −3 times of WHO recommended data (7.41 mM). The Job’s plot and mass spectral data support 1:1 composition of the complex [Al(HL)(OH)H 2 O](NO 3 ) 2 . The strongly emissive complex turns off upon addition of F − and is detected at the level of (LOD) 7.4 nM. Thus, F − , a harmful water pollutant, could be identified at much lower level of WHO recommended toxic limit (3.68 μM). The absorption and emission spectral features of HL and its Al +3 -complex have been explained by DFT computation of optimized geometries and calculation of molecular functions. The devised receptor is non-toxic and has been used in detecting Al +3 in the intracellular region of African green monkey kidney cells (Vero cells) and exhibits an INHIBIT logic gate with Al +3 and F − as chemical inputs by monitoring the emission mode at 520 nm. [ABSTRACT FROM AUTHOR]