Metal-organic frameworks as advanced platforms for radionuclide detection

The development of nuclear energy has significantly increased the prevalence of artificial radionuclides, mainly generated through nuclear fission processes, alongside naturally occurring radionuclides. These radionuclides, encompassing a wide array of elements, including ³H, ⁸⁵Kr, ⁹⁰Sr, ⁹⁹Tc, ^129/131I, ¹³⁷Cs, ²²²Rn, ²³²Th, and ^235/238U, exist in diverse chemical forms such as gases, ions, and molecular species, posing substantial risks to human health and environmental safety. Consequently, the precise detection and selective separation of these radionuclides are of paramount importance for the timely identification and mitigation of associated hazards. This review explores the application of metal-organic frameworks (MOFs) as advanced platforms for radionuclide detection, utilizing their structural tunability and versatile functionality. The discussion is systematically organized based on the chemical forms of radionuclides, categorizing them into gaseous, cationic, and anionic species. Key detection mechanisms employed by MOFs, including fluorescence sensing (via quenching, enhancement, and fluorochromism), scintillation techniques, colorimetric sensing, electrochemical sensing, and so on, are thoroughly examined. These approaches are analysed to elucidate their principles, practical implementations, and limitations.