Monodentate AIEgen Anchored on Metal‐Organic Framework for Fast Fluorescence Sensing of Phosphate

Herein, a novel sensor (TPE‐UiO‐66) was designed via anchoring monodentate tetraphenylethylene (TPE) onto UiO‐66 framework. The combination of the distinct aggregation‐induced emission (AIE) of TPE and the easy replacement of monodentate linker by guest phosphate, makes TPE‐UiO‐66 an ideal platform for sensing HPO₄^2–. Experimental results indicate that TPE‐UiO‐66 can selectively sense HPO₄^2– from other common anions. The limit of detection (LOD) can reach to 5.56 μmol·L^–1 and more importantly, TPE‐UiO‐66 also exhibits an ultra‐fast equilibrium response of 2 min, far faster than those of other sensors especially for UiO‐66‐NH₂. The combination of experimental analysis and density functional theory (DFT) calculations demonstrates that the high selectivity, high sensitivity and fast response of HPO₄^2– detection by TPE‐UiO‐66 can be attributed to the stronger coordination interactions of HPO₄^2– with Zr‐O cluster of UiO‐66 than that of TPE molecule. This study not only provides a potential probe for phosphate, but also represents a novel strategy to design stimuli‐responsive fluorescent MOF‐based sensors via using monodentate AIEgens.