Recent progress in current and emerging techniques for the detection of PFAS – the forever chemicals

Abstract

Per- and polyfluoroalkyl substances (PFAS) are now regulated at ultra-trace levels in drinking water, with guideline values in the low ng L⁻¹ (ppt) range in many jurisdictions, demanding highly sensitive, robust, and cost-effective monitoring tools. Regulatory drivers increasingly emphasize not only detection of legacy PFAS such as PFOS and PFOA, but also broader chemical coverage, routine compliance monitoring, and rapid screening at the point of use. This review critically surveys PFAS sensor technologies developed over the last decade, encompassing optical (colorimetric, fluorescence, and surface plasmon resonance), electrochemical (voltammetric, impedimetric, and potentiometric), and emerging biosensing and whole-cell reporter platforms. For each sensor class, typical limits of detection (from low ppb down to sub-ppt in optimized systems), dynamic ranges, regeneration, and compatibility with repeated measurements in real and complex water matrices are summarized. The underlying recognition and transduction principles—including molecularly imprinted polymers, host–guest interactions, ion-selective membranes, nanomaterial-enhanced interfaces, and biological recognition elements—are highlighted to connect materials design with analytical performance. Across these platforms, key advantages include miniaturization, rapid response, and potential integration into portable or on-line monitoring systems, whereas major limitations involve selectivity among structurally similar PFAS, matrix interferences, long-term stability, and limited multi-analyte capability. This review discusses how current research addresses these challenges through preconcentration strategies, sensor arrays, nanostructured materials, and integrated sample handling, and outlines future directions toward regulatory-grade, field-deployable PFAS sensors capable of continuous monitoring, multiplex detection, and scalable deployment in drinking water and environmental surveillance.