Colorimetric detection of Fe3+/2+ and fluorescent detection of Al3+ in aqueous media: applications and DFT calculations

Abstract

A new multifunctional colorimetric and fluorescent chemosensor 1 for Fe3+/2+ and Al3+ has been synthesized in the one-step procedure. The sensor 1 detected both Fe2+ and Fe3+ through the color change from yellow to brown and Al3+ via turn-on fluorescence. The binding stoichiometries of sensor 1 with Fe3+/2+ and Al3+ were proposed to be 1:1 with the analyses of ESI-mass and Job plot. Importantly, the detection limits of 1 for Fe3+/2+ (2.11 and 2.70 μM) and Al3+ (3.44 μM) were lower than the EPA guideline (5.37 μM) for Fe3+/2+ and WHO guideline (7.41 μM) for Al3+. Compound 1 was used to quantify ferric species (Fe3+) in real samples. Moreover, the sensing processes for Fe3+/2+ and Al3+ were proposed with the spectroscopic studies and theoretical calculations.