Recent progress in per- and polyfluoroalkyl substances (PFAS) sensing: A critical mini-review

Per- and polyfluoroalkyl substances (PFAS) are a class of fluorinated pollutants found widely in numerous industrial and consumer products. Their excellent heat, oil, and water resistance and slow degradation rate in nature lead to their persistent environmental accumulation with potential adverse impacts on various organisms, including humans. Although the current EPA-approved PFAS detection method is elegant and ultrasensitive, its broader application is greatly limited due to the associated high costs, lengthy detection times, and skilled personnel requirements. Hence, there is a strong demand for rapid, robust, low-cost, and accessible PFAS detection methods to expedite the treatment of contaminated media and control exposure to these emerging substances. Since the publication of our first PFAS sensing review in 2021, numerous new PFAS sensors have been developed and reported. Consequently, this critical review primarily focuses on recent advancements in PFAS sensing platforms, encompassing optical-based, electrochemical-based, and other novel sensing principle-based systems, as well as those that complement liquid chromatography coupled with tandem mass spectrometry, the gold standard for PFAS detection. The underlying detection mechanisms, sensing performances, and potential areas for improvement are thoroughly discussed. We hope that this article offers readers a review of alternative PFAS detection systems developed in recent years and inspires future innovations in field-deployable PFAS sensing technology.