Towards deployable electrochemical sensors for per- and polyfluoroalkyl substances (PFAS)

Per- and polyfluoroalkyl substances (PFAS) are an emerging class of pervasive and harmful environmental micropollutant with negative health effects on humans. Therefore, there has been extensive research into the remediation (i.e., the detection, extraction, and destruction) of these chemicals. For efficient extraction and destruction, PFAS contamination must be detected at its onset; however, conventional PFAS detection methods rely on sample collection and transport to a centralized facility for testing, which is expensive and time-consuming. Electrochemistry offers a robust, inexpensive, and deployable sensing strategy that could detect pollution at its onset; however, the electrochemical inactivity of PFAS necessitates the use of a surface functionalization strategy. Molecularly imprinted polymers (MIPs), which are a popular surface functionalization strategy, have been around since the 1980s for specific electrochemical detection and have expanded electrochemical detection to analytes that are not electrochemically active. MIPs have been more recently demonstrated for the detection of a variety of PFAS species, but additional advances must be made for realization of a deployable, electrochemical MIP-based sensor. This Feature highlights the history of MIPs for PFAS detection and our group's recent advances that are essential to enable the creation of a deployable electrochemical PFAS sensor: development of rigorous analytical standards to quantify interferent effects, miniaturization of the detection platform for quantification in river water, the use of ambient O₂ as the mediator molecule for detection, and the development of hardware for in-field multiplexed electrochemical sensing.