Amidoquinoline-based xylofuranose derivative for selective detection of Cu2+ in aqueous medium

Abstract

The amide derivatives of quinoline 1 and naphthalene 2 were synthesized after incorporating D(+) xylose moiety to recognize cations and anions in the aqueous medium. Amidoquinoline-based xylofuranose derivative 1 showed absorbance and fluorescence responses towards Cu2+ ions over other metal ions and anions in an aqueous medium. Sensor 1 showed a sensitivity limit of 0.87 µM with a 1:1 binding ratio for Cu2+ ions. The binding stoichiometry of the complex was established from Job plot and supported by the ESI-mass spectrum of the complex. Amidonaphthalene-based reference compound 2 was used to establish the binding mechanism between 1 and Cu2+ ion. Finally, FT-IR spectroscopy and DFT calculation executed the binding mode of 1 with Cu2+ in an aqueous medium. The effective fluorescence quenching of 1 with the presence of Cu2+ ions could be restored from Na2EDTA experiment. Sensor 1 showed selective and effective fluorescence quenching responses towards Cu2+ ions in an aqueous solution.