A highly selective chemosensor for Al3+ based on 2-oxo-quinoline-3-carbaldehyde Schiff-base

A new Schiff-base ligand ( 1 ) with good fluorescence response to Al 3+ , derived from 2-oxo-quinoline-3-carbaldehyde and nicotinic hydrazide, had been synthesized and investigated in this paper. Spectroscopic investigation revealed that the compound 1 exhibited a high selectivity and sensitivity toward Al(III) ions over other commonly coexisting metal ions in ethanol, and the detection limit of Al 3+ ions is at the parts per billion level. The mass spectra and Job’s plot confirmed the 1:1 stoichiometry between 1 and Al 3+ . Potential utilization of 1 as intracellular sensors of Al 3+ ions in human cancer (HeLa) cells was also examined by confocal fluorescence microscopy.