A reversible fluorescent-colorimetric chemosensor based on a novel Schiff base for visual detection of CO32− in aqueous solution

Abstract

A reversible fluorescent colorimetric chemosensor for rapid detection of carbonate ion has been developed based on a novel bis-Schiff base. The chemosensor L employed here is easy to synthesize, eco-friendly and cost effective. It exhibits excellent selectivity and sensitivity towards carbonate ion by changes in both the absorption and fluorescence intensity. The anion recognition occurs indirectly through coordination of a counter metal ion to the Schiff base ligand exhibiting a colour change from colourless to yellow. Microstructural features of L and L + M⁺ have been investigated by SEM images. The sensitivity of the absorbance based assay (96 nM) for carbonate ion is the lowest ever reported in the literature. The chemosensor L providing rapid response time with sufficiently low detection limit may be useful as a valuable practical sensor for environmental analyses of carbonate ion.