Pore-Engineered Luminescent MOF Sensors for PFAS Recognition in Water

Per- and polyfluoroalkyl substances (PFAS) are persistent contaminants in water that pose severe threats to environmental integrity and public health. Luminescent sensing using porous materials has emerged as a highly efficient strategy for daily recognition, owing to its high efficiency, simplicity, and sensitivity. However, systematic investigations into the pore structure-function relationship that govern PFAS detection remain largely lacking, which hindered the rational design of advanced PFAS sensors. Herein, a linker installation strategy is employed to precisely engineer the pore environments of metal-organic frameworks (MOFs) in a modular manner without compromising structural integrity for PFAS recognition in water. A library of 13 PCN-700 derivatives with systematically regulated pore volumes was constructed, revealing that enhanced pore accessibility directly boosts sensing performance. Notably, the amino groups in PCN-700 significantly improve the sensing sensitivity, achieving up to 3-fold higher quenching efficiencies through strengthened host-guest interactions. Further adjustment of functional group densities uncovers a trade-off between functional group loading and pore accessibility. By disentangling the respective contributions of pore volume modulation by various functional groups, the design principles are provided for the development of robust and high-performance MOF-based luminescent sensors to address PFAS monitoring challenges in water.