A Chromone Based Fluorescent Probe for the Effective Detection of Aluminium Ion

A new chromone moiety fused with phenyl hydrazine carboxamide as a binding site for metal ion was designed and synthesized as a colorimetric/fluorimetric probe for selective sensing of Al³⁺ ion. The absorption and fluorescence spectral results showed selective and sensitive recognition of Al³⁺ with no significant interference from other competitive metal ions. The addition of Al³⁺ to R brought a prompt color change from colorless to yellow and the turn-on fluorescence response with Al³⁺ among different cations was studied. The visible color change and turn-on fluorescence Al³⁺ ion with R was attributed to the intra molecular charge transfer transition. The plausible binding nature of the receptor with Al³⁺ has also been anticipated by the results of ¹H NMR and mass spectral analysis. For the practical effectiveness, test strip prepared using probe R was successfully applied to monitor the presence of Al³⁺ ion in aqueous medium.