Electrochemical Sensing of Perfluorooctanoic Acid via a Rationally Designed Fluorine-Functionalized Cu-MOF and In-Depth Analysis of Sensing Mechanism

作者：Xuan Zheng, Cun Li, Nairong Yang, Li Niu, Feng Gao, Qingxiang Wang · 发表于：Analytical Chemistry · 年份：2025 · DOI：10.1021/acs.analchem.5c00745 · 被引用次数：68 · 研究领域：Gas Sensing Nanomaterials and Sensors、Analytical Chemistry and Sensors、Conducting polymers and applications

Perfluorooctanoic acid (PFOA), a prominent member of the per- and polyfluoroalkyl substance (PFAS) family, has emerged as a new perpetual pollutant posing significant environmental and health risks, necessitating developing highly selective materials for its sensitive detection in water. In this work, we developed an electroactive fluorine-functionalized Cu-MOF (F–Cu–NH 2 BDC) through postmodification of the copper-2-amino-terephthalic acid (Cu–NH 2 BDC) MOF with 2,3,5,6-tetrafluoroterephthalaldehyde (TFTA). Experimental and computational results suggested that F–F interactions between the decorated tetrafluorobenzaldehyde groups and PFOA, as well as among the PFOA molecules themselves, would induce self-aggregation of PFOA molecules on the surfaces or in the pores of F–Cu–NH 2 BDC. This specific aggregation inhibited contact and electron transfer between F–Cu–NH 2 BDC and the electrolyte, resulting in a decrease in the inherent electrochemical Cu 2+ /Cu + redox signal from F–Cu–NH 2 BDC. Based on this, an F–Cu–NH 2 BDC-based label- and probe-free PFOA electrochemical sensor was exploited with an excellent linear range from 5 pM to 500 μM and an extremely low detection limit of 3.54 pM, surpassing most currently reported electrochemical and nonelectrochemical PFAS sensors. This sensor also exhibited good stability, reproducibility, and anti-interference performance, enabling the accurate measurement of PFOA concentrations in actual commercial drinking water. These findings sh...