Eu(III) functionalized Zr-based metal-organic framework as excellent fluorescent probe for Cd2+ detection in aqueous environment

A Eu-doped metal-organic framework (Uio-66-NH2-Eu) has been synthesized under an appropriate hydrothermal condition and used as a luminescence sensor for Cd2+ detection. Uio-66-NH2-Eu shows excellent luminescence and good fluorescence stability in water which performs a remarkable enhancement effect (∼13 times as much as original one) in the luminescence emission of Eu3+ upon the introduction of Cd2+. This is a better example for detecting Cd2+ in aqueous solutions based on a lanthanide functionalized metal-organic frameworks (MOFs). Most importantly, the luminescence probe of Cd2+ shows a low detection limit (0.22 μM), a broad linear range (0.22-500 μM), fast detection time (<5 min), and the signals can be observed by the naked eyes under the irradiation of UV light of 365 nm. Subsequently, Uio-66-NH2-Eu was developed as a highly selective and sensitive probe for detection of Cd2+ in aqueous solutions. This work may be provided a possibility for Cd-detection in other biological systems.