A water-stable lanthanide-MOF as a highly sensitive and selective luminescence sensor for detection of Fe3+ and benzaldehyde

This paper studies the application of lanthanide metal-organic frameworks (Ln-MOFs) in fluorescence detection. The europium-based metal-organic frameworks (Eu-MOFs) are synthesized by a facile solvothermal method, and then the as-prepared MOF were further characterized by PXRD, FT-IR, TG, EDS, SEM, UV–vis spectra and fluorescence spectroscopy. The results demonstrate that Eu-MOF exhibits an intense red fluorescence, which can be readily observed by naked eye in solid state, good structural stability and fluorescence stability in aqueous solution or other organic solvents, especially high selectivity and sensitivity to Fe3+ and benzaldehyde and the visible color change by the naked eye under UV-light. This luminescent MOF can be used to detect Fe3+ and benzaldehyde in an aqueous environment with low detection limits of 0.027 μM for Fe3+ and 0.011 μM for benzaldehyde.