| Abstract Scope |
Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants of concern in both water and air, creating an urgent need for low-cost, low-power, and highly sensitive environmental sensors. In this work, we report 2D MoS₂-based field-effect transistor (FET) nanosensors for rapid, sensitive, and selective PFAS detection in aqueous and airborne environments. After functionalization of the MoS₂ channel, the FET sensors exhibited strong and selective interactions with PFAS molecules. In water, the sensors achieved low limits of detection of 1.0 ppt for PFOA and 0.95 ppt for PFNA, below the EPA maximum contaminant levels of 4.0 ppt and 10 ppt, respectively. For airborne PFAS detection, the sensors showed signal-to-noise ratios of 6–30, response times of 25–35 s, and a LoD of 0.076 ppm for 6:2 FTOH, as well as a LoD of 0.050 ppm for perfluoroheptane. A portable prototype system was also developed for on-site PFAS monitoring. |