PFAS Detection Breakthrough with Transportable New Sensor

They linger in our water, our blood, and the atmosphere—”ceaselessly chemical substances” which can be notoriously tough to detect.

But researchers on the UChicago Pritzker School of Molecular Engineering (UChicago PME) and Argonne National Laboratory have collaborated to develop a novel technique to detect miniscule ranges of per- and polyfluoroalkyl substances (PFAS) in water. The technique, which they plan to share through a transportable, handheld system, makes use of distinctive probes to quantify ranges of PFAS “forever chemicals,” a few of that are poisonous to people.

“Existing methods to measure levels of these contaminants can take weeks, and require state-of-the-art equipment and expertise,” mentioned Junhong Chen, Crown Family Professor on the UChicago Pritzker School of Molecular Engineering and Lead Water Strategist at Argonne National Laboratory. “Our new sensor device can measure these contaminants in just minutes.”

The expertise, described within the journal Nature Water, can detect PFAS current at 250 components per quadrillion (ppq) – like one grain of sand in an Olympic-sized swimming pool. That provides the check utility in monitoring ingesting water for 2 of probably the most poisonous PFAS—perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)—for which the U.S Environmental Protection Agency (EPA) not too long ago proposed limits of 4 components per trillion.

“PFAS detection and elimination is a pressing environmental and public health challenge,” mentioned Andrew Ferguson, Professor of Molecular Engineering at UChicago PME. “Computer simulations and machine learning have proven to be an incredibly powerful tool to understand how these molecules bind to molecular sensors and can guide experimental efforts to engineer more sensitive and selective molecular probes.”

“Even though they are typically present at miniscule concentrations, PFAS do have certain molecular characteristics that differentiate them from other things dissolved in water, and our probes are designed to recognize those features,” mentioned Seth Darling, a Senior Scientist at each Argonne and UChicago.

A detection problem

PFAS are oil- and water resistant chemical substances which can be used for a variety of client and industrial merchandise, together with non-stick pots and pans, quick meals packaging, firefighting foam, raincoats, and stain-resistant carpeting. Often referred to as “forever chemicals,” they’re extremely long-lasting and don’t naturally degrade, however as a substitute accumulate within the atmosphere and folks’s our bodies over time.

In latest years, research have linked PFAS to well being considerations, together with cancers, thyroid issues and weakened immune techniques. In gentle of a few of these findings, the EPA proposed the brand new limits for PFOS and PFOA.

“The problem with enforcing these limits is that it’s very challenging and time-consuming to detect PFAS,” mentioned Chen. “You currently can’t just take a sample of water and test it at home.”

The gold commonplace for measuring PFAS ranges is an costly laboratory check referred to as liquid chromatography/tandem mass spectrometry, which separates chemical compounds and supplies data on every one.

Researchers making an attempt to make their very own quicker and cheaper PFAS checks face a couple of challenges: for one factor, PFAS chemical substances are sometimes current in water at a lot decrease concentrations than dozens of different, extra widespread contaminants. In addition, there are millions of completely different PFAS chemical substances with solely slight variations between their chemical constructions—however vital variations of their well being results and rules.

But Chen’s workforce has been creating extremely delicate, moveable sensors on pc chips for the final fifteen years. Chen is already utilizing the expertise in a lead sensor for faucet water, and his lab group suspected that the identical technique might be utilized in PFAS sensing. Their proposal to adapt the expertise for PFAS turned a part of the National Science Foundation Water Innovation Engine in the Great Lakes. 

Designed by AI

The gist of Chen’s sensor is that if a PFAS molecule attaches to his system, it modifications {the electrical} conductivity that flows throughout the floor of the silicon chip. But he and his colleagues had to determine the way to make every sensor extremely particular for only one PFAS chemical—akin to PFOS.

To do that, Chen, Ferguson, Darling, and workforce turned to machine studying to assist choose distinctive probes that would sit on the sensing system and ideally bind solely the PFAS of curiosity. In 2021, they gained a Discovery Challenge Award from the UChicago Center for Data and Computing (CDAC) to assist their use of synthetic intelligence in designing PFAS probes.

“In this context, machine learning is a tool that can quickly sort through countless chemical probes and predict which ones are the top candidates for binding to each PFAS,” mentioned Chen.

In the brand new paper, the workforce confirmed that one in every of these computationally-predicted probes does certainly selectively bind to PFOS—even when different chemical substances widespread in faucet water are current at a lot greater ranges. When water containing PFOS flows by their system, the chemical binds to the brand new probe and modifications {the electrical} conductivity of the chip. How a lot the conductivity modifications is determined by the extent of PFOS.

To make sure that the readings from the brand new system had been right, the workforce collaborated with EPA and used EPA-approved liquid chromatography/tandem mass spectrometry strategies to substantiate concentrations and verified that the degrees had been according to what the brand new system detected. The workforce additional confirmed that the sensor might keep its accuracy even after many cycles of detection and rinsing, suggesting the potential for real-time monitoring.

“Our next step is to predict and synthesize new probes for other, different PFAS chemicals and show how this can be scaled up,” says Chen. “From there, there are many possibilities about what else we can sense with this same approach— everything from chemicals in drinking water to antibiotics and viruses in wastewater.”

The finish end result could finally be that customers can check their very own water and make higher decisions about their atmosphere and what they devour. 

Reference: Wang Y, Jang HJ, Topel M, et al. Reversible parts-per-trillion-level detection of perfluorooctane sulfonic acid in faucet water utilizing field-effect transistor sensors. Nat Water. 2025:1-11. doi: 10.1038/s44221-025-00505-9

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