The development of new water sensing and remediation materials is imperative for addressing the challenge of mitigating per- and polyfluoroalkyl substances (PFAS) in aquatic systems. The integration of experimental characterization and theoretical understanding, in conjunction with their dynamic interplay, will substantially enhance the fundamental research on PFAS sensing. The objective of this proof-of-concept project is to molecularly engineer a field-effect transistor (FET) sensing platform to detect six regulated PFAS in water—perfluorooctanoic acid, perfluorooctane sulfonic acid, perfluorohexane sulfonic acid, perfluorononanoic acid, hexafluoropropylene oxide-dimer acid, and perfluorobutane sulfonic acid. The incorporation of molecular modeling and artificial intelligence/machine learning (ML)-assisted design and analysis strategies will enhance the sensor's sensitivity and specificity. Upon the successful completion of the one-year study, the proven concept and demonstrated sensing results will offer insights into molecular engineering and design of new chemical probes/materials for rapid, accurate, selective, and real-time detection of various PFAS compounds.

A remote gate FET sensing technology developed by Principal Investigator Junhong Chen will be utilized. The methodology involves the fabrication of a sensor array comprising three distinct RG electrodes that will be conjugated with α, β, γ-cyclodextrin (CD) molecular probes to facilitate the detection of the six most prevalent PFAS species. These RG electrodes will be interconnected in parallel with a commercial metal oxide–semiconductor FET, which incorporates multiple FETs. The response pattern from the sensor array will be recorded and subsequently analyzed using a ML model to identify the unique binding signatures for each PFAS species. In addition, the binding affinity between CD probes and PFAS molecules will be investigated through molecular dynamics simulations to predict and engineer the chemical sensitivity and specificity of the probes over other prevalent organic compounds to mitigate sensing interference.

Upon successful completion, the project results will offer insights into molecular engineering and design of new chemical probes/materials for rapid, accurate, selective, and real-time detection of PFAS compounds in water. The integration of experimental characterization and theoretical understanding, along with their dynamic interplay, will significantly enhance the fundamental research on PFAS sensing. It will also provide knowledge for the development of new water sensing and remediation materials, contributing to fit-for-purpose water reuse. Outcomes of this project can further bring significant opportunities for potential stakeholders in risk management of PFAS-impacted sites in water. (Anticipated Project Completion - 2027)