A facile fluorescent probe based on coumarin-derived Schiff base for Al~(3+) in aqueous media

摘要

A facile coumarin-based Schiff base sensor, 7-hydroxy-8-((2-hydroxy-phenylimino)methyl)-coumarin (H2L), has been designed and synthesized for selective detection of Al~(3+) in methanol-water (1:1, v/v). A fluorescence enhancement of 12-fold at 528 nm can be realized upon addition of 5.0 equiv. Al~(3+) with excitation at 421 nm. The mechanism of C=N isomerization, coupled with photoinduced energy transfer, is proposed to explain the observed spectral response. Most importantly, this Al~(3+) sensor has good water-solubility and can be excited with light in the visible range.