MOF&COF for per- and polyfluoroalkyl substance analysis: State of the art and future prospects

Perfluoroalkyl substances (PFAS), comprising thousands of fluorinated compounds, have become a global concern due to their environmental persistence, bioaccumulation potential, and toxicity. Metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) have emerged as highly promising materials for PFAS analysis, thanks to their customizable pore architectures, high specific surface areas, and versatile functional groups. This review comprehensively explored the unique advantages of framework materials that make them highly effective for PFAS detection. It delved into the fluorescent and electrochemical methods employed in PFAS detection using MOFs and COFs, providing advantages such as short detection times, low detection limits, and high portability. The review also underscored the utility of MOFs and COFs in various sample pretreatment techniques. These methods utilized the strong adsorption capacities of MOFs and COFs to efficiently enrich PFAS from complex matrices, thereby significantly enhancing the accuracy and sensitivity of analytical procedures. The review analyzed MOF and COF preparation methods and their impact on performance, while highlighting challenges including the need for more efficient synthesis, cost reduction, improved stability, and better selectivity in complex samples. Future research should prioritize enhancing the efficiency, scalability, and eco-friendliness of MOF and COF synthesis for PFAS analysis, exploring the potential of MOF/COF nanozymes, and improving their performance through defect engineering and functional design. Additionally, novel analytical methods for broader PFAS characterization in different media should be developed, along with high-performance MOFs/COFs tailored for ultrashort-chain PFAS separation and deeper molecular-level understanding of adsorption mechanisms.