Abstract: Given the persistence, bioaccumulation and high testing costs of typical PFASs contaminants in the firefighters' turnout gear, 2-amino-terephthalic acid served as ligand and zirconium dichloride as metal source, then the fluorescent dye RGH with pH response was encapsulated into zirconium organic cage NH2-Zr-MOC with active amino group by the strategy of in-situ encapsulation, and the double-emission fluorescence sensor RGH-NH2-Zr-MOC with good chemical stability and high fluorescence quantum yield was fabricated. With the help of strong hydrogen bond and electrostatic interactions between PFOA, PFOS and fluorescence sensor, the highly sensitive detection of PFOA and PFOS contaminants was realized. The results showed that the fluorescence sensor had high sensitivity to PFOA and PFOS and strong anti-interference capability, and the detection limits can reach 20.7 nmol/L and 12.9 nmol/L, respectively (S/N=3). Further, with the help of ultraviolet light irradiation with 254 nm and RGB numerical analysis method, the visually quantitative detection of PFASs (all converted as the percentage of PFOS) for firefighting protective clothing was realized. The accuracy of this method was comparable to that of HPLC-MS/MS, and the cost was very low. It provides a simple and practically rapid detection technology for firefighters' occupational exposure protection.

Key words: turnout gear, PFASs pollutants, metal-organic cage, fluorescence sensor, visual detection