Ultrasensitive and Selective Detection of Uranium by a Luminescent Terbium-Organic Framework

Detection and remediation of radioactive components have become the focus of worldwide research interest due to the ever-increasing generation of nuclear waste and the concerns on nuclear accidents. Among the numerous radionuclides, uranium and its isotopes receive the most attention because of their high proportion in nuclear waste and long half-life. Herein, a highly luminescent terbium-organic framework, formulated as [Tb₄(C₂₉O₈H₁₇)₂(NO₃)₄(DMF)₄(H₂O)₄]·4H₂O·8.5DMF (YTU-100), with exceptional sensitivity and selectivity toward uranium was successfully prepared. The material exhibits fast adsorption kinetics and moderate sorption capacity. Interestingly, the luminescence intensity variation highly correlates to the amount of adsorbed uranium, which results in a quantitative, accurate, and selective uranium detection manner. The detection limits in deionized water and tap water were determined to be 1.07 and 0.75 ppb, respectively, which are lower than the US Environmental Protection Agency standard of the maximum contamination of uranium in drinking water. YTU-100 offers an alternative approach for building multifunctional MOFs used for simultaneous detection and removal of uranium from aqueous solutions.