Breakthrough in PFAS Detection on a Portable Chip
Researchers from the University of Chicago’s Pritzker School of Molecular Engineering (UChicago PME) and Argonne National Laboratory have developed a handheld sensor that can detect PFAS “forever chemicals” in water within minutes. The technology represents a significant shift away from traditional laboratory tests, offering a practical tool for rapid screening of drinking water and environmental samples for PFAS such as PFOA and PFOS.
From Lab Bench to Handheld: How the Sensor Works
The core idea is simple in principle but sophisticated in execution: PFAS molecules binding to specially designed probes on a silicon chip cause measurable changes in electrical conductivity. When PFAS attach to a probe on the chip surface, the device registers a signal whose magnitude correlates with the PFAS concentration. The result is a rapid, on-site readout that can be interpreted without sending samples to a central lab.
To achieve the necessary specificity—discriminating PFOS or PFOA from a long list of other waterborne substances—the team turned to machine learning. By screening thousands of potential probes, the AI helped select those most likely to bind selectively to a given PFAS chemical. This synergy of sensor design and artificial intelligence enabled the creation of a portable device capable of measuring PFAS at extremely low concentrations.
Why This Matters: Sensitivity, Speed, and public Health
The sensor can detect PFAS at 250 parts per quadrillion (ppq), a level comparable to finding a single grain of sand in an Olympic-sized swimming pool. That sensitivity is particularly relevant for drinking-water safety, as the EPA has proposed limits in the parts-per-trillion range for PFOS and PFOA. The rapid, field-ready detector could transform how communities monitor water quality, enabling proactive responses to contamination events.
Lead investigator Junhong Chen notes that current standard methods—typically liquid chromatography–tandem mass spectrometry (LC-MS/MS)—are accurate but slow, costly, and confined to equipped laboratories. The new handheld approach promises a complementary path: fast, cheaper, and accessible testing that can guide decision-making while more comprehensive analyses are scheduled for confirmation in the lab.
Independent Validation and Real-World Readiness
To ensure reliability, the researchers collaborated with the Environmental Protection Agency (EPA) to validate readings using established LC-MS/MS methods. The results showed agreement between the handheld device and traditional laboratory measurements, bolstering confidence in the approach’s accuracy.
Durability and reusability were also demonstrated—the sensor maintained performance across multiple detection and rinsing cycles, a key requirement for ongoing monitoring in homes, schools, and municipal water systems.
Next Steps: Expanding the Probe Library
Looking ahead, the team aims to expand the suite of probes to detect a broader range of PFAS chemicals. They also envision scaling the technology to other contaminants, such as antibiotics or viruses in wastewater, using the same AI-guided sensing framework. Chen emphasizes that the ultimate goal is consumer-accessible testing that informs safer consumption and environmental choices.
Broader Impact: A New Era for Water Safety
Beyond the scientific novelty, this handheld PFAS detector could empower communities to take immediate action. If people can test their tap water at home or at local testing sites and obtain trustworthy results in minutes, reporting and mitigation efforts could accelerate, reducing exposure to potentially toxic PFAS and improving public health outcomes.
Reference: Wang Y, Jang HJ, Topel M, et al. Reversible parts-per-trillion-level detection of perfluorooctane sulfonic acid in tap water using field-effect transistor sensors. Nat Water. 2025:1-11. doi: 10.1038/s44221-025-00505-9
