Recent ultratrace per- and polyfluoroalkyl substance (PFAS) detectors

Recent advances in per- and polyfluoroalkyl substance (PFAS) detection exploit engineered fluorophilic interfaces, conjugated polymers, molecular imprinting, and nanoscale transduction to deliver rapid, selective, and field-compatible sensors with ppt to ppq level sensitivity. This minireview discusses advances made over the last five years in five material classes-organic molecules and assemblies, polymers, nanoparticles, carbon nanotubes, and metal-organic frameworks-highlighting how tailored recognition motifs and controlled assembly convert PFAS binding into optical, electrochemical, or resistive signals. Representative strategies discussed include interrupted energy transfer and amplifying fluorescent polymers for ratiometric and turn-off fluorescence sensing, molecularly imprinted and nanostructured electrodes for impedimetric and voltammetric quantification, single-particle collision electrochemistry and MXene-metal hybrids for ultralow electrochemical detection, printed surface-enhanced Raman spectroscopy (SERS) substrates for molecular fingerprinting, and 2D conductive MOFs for chemiresistive ppt-level responses. We evaluate analytical performance, selectivity trends across chain length and headgroup chemistry, matrix effects in real waters, and practical considerations for on-site deployment. The review concludes by identifying key challenges-stability, standardization, and multiplexed detection-and outlines promising directions toward translating ultratrace PFAS sensors into robust environmental monitoring tools.