Facile one-step solvothermal synthesis of a luminescent europium metal-organic framework for rapid and selective sensing of uranyl ions.

A simple, cost-effective, and portable uranium sensory material with adequate selectivity is increasingly urgent and would be of great importance in environmental monitoring of radionuclides. Herein, we report a novel luminescent europium metal-organic framework (Eu-MOF) with plenty of Lewis basic sites for binding uranyl ions (UO22+), the most common form of uranium in solution, through a facile one-step solvothermal synthetic route. The mesoporous structure consists of europium nodes and flexible nitrogen-containing ligands with a 29.2 × 20.5 Å2 channel along the c-axis. Furthermore, the obtained material displays characteristic fluorescence of trivalent Eu3+ and could be applied as a turn-off sensory probe targeting UO22+ in solution. Differential fluorescent quenching occurred upon a series of potential interfering ions compared to UO22+ and the detection limit as low as 0.9 μM was achieved with a rapid response. Graphical abstract.