From Molecular Designs to Nanomaterials for Electrochemical PFAS Detection: A Review
Abstract
The pervasive occurrence of per- and polyfluoroalkyl substances (PFAS) and the implementation of stringent regulatory guidelines necessitate rapid, highly sensitive analytical methodologies. Although liquid chromatography-tandem mass spectrometry (LC-MS/MS) remains the gold standard, its complexity and limited portability hinder large-scale and real-time monitoring. Electrochemical sensing has emerged as a promising alternative. To overcome the intrinsically low electroactivity of PFAS, electrochemical sensing leverages tailored nanomaterial interfaces to convert specific molecular recognition events into measurable electrical signals. This review systematically elucidates the molecular-level interaction mechanisms between trace PFAS and advanced sensing nanomaterials, specifically molecularly imprinted polymers (MIPs), metal–organic frameworks (MOFs), and MXenes. We detail how the unique amphiphilic architecture of PFAS is targeted via electrostatic interactions, hydrophobic interactions, fluorine–fluorine (F···F) interactions, and hydrogen-bonding interactions to achieve highly selective recognition. By integrating adsorption modeling, spectroscopic characterization, and density functional theory (DFT), we establish a multiscale understanding that links macroscopic sensing behavior to underlying molecular-level interactions. Finally, we discuss the critical factors governing sensor performance and advocate for future research focusing on rational interface design, broadening the detection spectrum to emerging alternatives, and translating laboratory prototypes into reliable real-world monitoring devices.