Comprehensive Summary Radiation scintillators that combine high sensitivity, stability, and multimodal detection capability are highly desirable for advanced radiation imaging and monitoring. Herein, we report a rational lanthanide‐doping strategy to construct a high‐performance metal–organic framework (MOF) scintillator, namely Eu 3+ ⊂Bi‐ndc . In this design, high‐atomic‐number Bi 3+ nodes serve as efficient X‐ray absorbers, while Eu 3+ ions act as isolated luminescent activators, and rigid 2,6‐naphthalenedicarboxylate (ndc 2– ) ligands function as effective antennae to facilitate energy transfer and suppress non‐radiative relaxation. Under X‐ray excitation, Eu 3+ ⊂Bi‐ndc shows intense radioluminescence with a low detection limit of 2.5 μGy·s –1 , a light yield of 25,695 photons MeV –1 , and outstanding irradiation stability. Flexible scintillating films fabricated from Eu 3+ ⊂Bi‐ndc enable high‐resolution X‐ray imaging with a spatial resolution of approximately 7 lp·mm –1 . Remarkably, Eu 3+ ⊂Bi‐ndc also exhibits measurable β‐ray–induced scintillation, representing the first example of a lanthanide‐containing MOF functioning as a β‐ray scintillator. This study advances a synergistic high‐ Z /lanthanide MOF paradigm that bridges X‐ray and β‐ray scintillation, paving the way for novel multifunctional radiation detectors.
Yang et al. (2026) studied this question.