Advances in Nanosensor Technologies for PFAS Detection: A Review

Per- and polyfluoroalkyl substances (PFAS) present a significant environmental and health threat due to their persistence, widespread contamination, and toxicological effects. Despite stringent regulatory limits and growing monitoring efforts, conventional analytical techniques, such as LC-MS/MS, are limited by complexity, cost, and throughput. Recent developments in nanosensor technologies have demonstrated substantial potential to overcome these challenges, offering ultrasensitive, selective, rapid, and portable detection of PFAS. This review systematically examines state-of-the-art PFAS nanosensors categorized by their transduction principles—electrochemical, optical, and bio-based—highlighting representative strategies involving metal nanoparticles, metal–organic frameworks, molecularly imprinted polymers, fluorescent nanomaterials, plasmonic nanostructures, microresonators, and biorecognition elements. We further explore the integration of machine learning as an enabling technology, showcasing its role in enhancing sensitivity, robustness, and selectivity through advanced data analytics and sensor optimization, exemplified by recent ultrasensitive surface-enhanced Raman scattering studies. Finally, we discuss the current limitations, future directions, and opportunities for nanosensors to provide scalable and reliable solutions for real-time environmental monitoring and comprehensive PFAS risk management.