Fluorescent sensor for selective detection of Al3+ based on quinoline–coumarin conjugate

Abstract

A fluorescence probe, 8-formyl-7-hydroxyl-4-methyl coumarin – (2′-methylquinoline-4-formyl) hydrazone (L) has been synthesized. The chemosensor is found preferential binding to Al3+ in presence of other competitive ions with associated changes in its optical and fluorescence spectra behavior. Upon addition of Al3+ to a solution of L, it shows 200-fold enhancement of fluorescence intensity which might be attributed to form a 2:1 stoichiometry of the binding mode of LAl(III) and the chelation enhanced fluorescence (CHEF) process at 479nm in ethanol. The lowest detection limit for Al3+ is determined as 8.2×10−7M.