Ultra-selective recognition of UO22+via triggering its intrinsic luminescence using a precisely designed europium metal–organic framework

A novel method for highly selective recognition of UO₂²⁺ is proposed based on a [Eu(pyridine-2,5-dicarboxylic acid N-oxide)] (Eu-PDA) metal-organic framework. Benefiting from the unique chemical structure of Eu-PDA, energy transfer from PDA to UO₂²⁺ was enabled, resulting in the highly up-regulated fluorescence of UO₂²⁺. The Eu-PDA probe showed excellent specificity to UO₂²⁺ over numerous interfering species, as the intrinsic emissions of UO₂²⁺ were triggered.