Uranyl-ion Directed Hydrogelation of Cholate for Enhanced Emission Resolution and Energy Transfer-driven Sensing

In this work, we report the first example of an actinide (UO₂ ²⁺) induced hydrogel formation. We discovered that the gel phase led to a remarkable improvement in the resolution of the emission from the uranyl cation. This phenomenon was previously seen only in sophisticated uranyl complexes in organic solvents or in the solid-state. The organized and confined gel microenvironment facilitated efficient energy transfer from UO₂ ²⁺→ Eu³⁺ in the hydrogel matrix. Additionally, this "turn-on" energy transfer strategy provided a simple method for uranyl sensing using commercially available ingredients.