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 HPO42-. Experimental results indicate that TPE-UiO-66 can selectively sense HPO42- from other common anions. The limit of detection (LOD) can reach to 5.56 mu mol center dot 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 HPO42- detection by TPE-UiO-66 can be attributed to the stronger coordination interactions of HPO42- 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.

Automated summary

TPE-UiO-66 is a highly sensitive and selective sensor for detecting HPO42-, with a detection limit of 5.56 mu mol center dot L-1 and a rapid equilibrium response time of 2 minutes.