Hydrolytically Stable Zr-Based Metal-Organic Framework as a Highly Sensitive and Selective Luminescent Sensor of Radionuclides

Effective detections of radionuclides including uranium and its predominantfission products, for example, iodine,are highly desired owing to their radiotoxicity and potential threatto human health. However, traditional analytical techniques ofradionuclides are instrument-demanding, and chemosensorstargeted for sensitization of radionuclides remain limited. In thisregard, we report a sensitive and selective sensor of UO22+and I-based on the unique quenching behavior of a luminescent Zr-basedmetal-organic framework, Zr6O4(OH)4(OH)6(H2O)6(TCPE)1.5middot(H2O)24(C3H7NO)9(Zr-TCPE). Immobilization of the lumines-cent tetrakis(4-carboxyphenyl)ethylene (TCPE4-) linkers by Zr6nodes enhances the photoluminescence quantum yield ofZr-TCPE, which facilitates the effective sensing of radionuclides in aturn-offmanner. Moreover,Zr-TCPEcan sensitively and selectively recognize UO22+and I-ions with the lowest limits ofdetection of 0.67 and 0.87 mu g/kg, respectively, of which the former one is much lower than the permissible value (30 mu g/L) definedby the U.S. EPA. In addition,Zr-TCPEfeatures excellent hydrolytic stability and can withstand pH conditions ranging from 3 to 11.To facilitate real-world applications, we have further fabricated polyvinylidenefluoride-integratingZr-TCPEas luminescence-basedsensor membranes for on-site sensing of UO22+and I-.

Automated summary

This study presents a sensitive and selective sensor based on a luminescent Zr-based metal-organic framework for the effective detection of radionuclides UO22+ and I-. The sensor exhibits low detection limits and excellent stability, making it a promising tool for real-world applications.