Ultra-Sensitive Nanosensor for Rapid Detection of Pfas in Simulated Drinking Water

Per- and polyfluoroalkyl substances (PFAS) are a class of persistent synthetic compounds, often called “forever chemicals,” that pose a significant threat to public health and the environment. Standard detection methods primarily rely on liquid chromatography and mass spectrometry [1], which is expensive, time-intensive, and requires trained personnel and laboratory infrastructure. While emerging approaches using metal-organic frameworks (MOFs), molecularly imprinted polymers, and lateral flow assays have been explored, they have yet to provide a solution that simultaneously offers part-per-trillion (ppt) sensitivity, high speed detection, and portability [2]–[5]. There is an urgent need for a sensor technology that can provide rapid, on-site, and ultra-sensitive detection to meet regulatory goals, such as the U.S. EPA's 4 ppt health advisory for PFAS [6]. This work addresses this challenge by presenting a novel fluorinated nanowire electrochemical sensor. We leverage a vertically aligned gold “nanograss” morphology to achieve a massive surface-area-to-volume ratio [7]. The wires are then functionalized with perfluoroalkylterminated alkane-thiols (F-thiols) for high PFAS selectivity [8]. We report, for the first time, a sensor based on this platform capable of detecting PFAS at sub-part-pertrillion levels in simulated drinking water. This approach enables ultrafast detection using electrochemical impedance spectroscopy (EIS) and requires only a small sample volume for a viable path toward portable and rapid PFAS monitoring.