Spurred by new regulations, the race is on for low-cost PFAS sensorsResearchers seek to improve the selectivity and sensitivity of field-deploya...

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Spurred by new regulations, the race is on for low-cost PFAS sensorsResearchers seek to improve the selectivity and sensitivity of field-deploya...
Spurred by new regulations, the race is on for low-cost PFAS sensors
Researchers seek to improve the selectivity and sensitivity of field-deployable devices that can detect ultralow levels of the contaminants in water
by Britt E. Erickson
April 30, 2023 | A version of this story appeared in Volume 101, Issue 14
Credit: C&EN/Shutterstock

Spurred by new regulations, the race is on for low-cost PFAS sensors

Credit: Courtesy of Charmi Chande/Essence Diagnostics
A graduate student analyzes per- and polyfluoroalkyl substances with a prototype device being developed at the New Jersey Institute of Technology.

Testing for per- and polyfluoroalkyl substances (PFAS) in drinking water is big business, and it’s about to get a lot bigger because of new limits proposed by the US Environmental Protection Agency for six of the so-called forever chemicals. Many researchers are hoping to cash in on the growing demand for PFAS testing by commercializing low-cost, portable sensors that can rapidly screen water for the contaminants. Scientists are excited about what these sensors can do, but it will likely be a few years before a commercial product is available. First, researchers must improve the sensitivity so they can detect PFAS at the low part-per-trillion limits proposed by the EPA. And they need to improve the selectivity of sensors to be able to differentiate between the thousands of PFAS on the market. The stability of field-portable sensors over time is also a challenge.

For some scientists, the quest to develop an easy-to-use, low-cost sensor for detecting per- and polyfluoroalkyl substances (PFAS) in drinking water is personal. “I bought a new house, and I got this letter that said apparently we had PFAS in our water and we needed a reverse osmosis system,” says Sagnik Basuray, a chemical and materials engineer at the New Jersey Institute of Technology.

Basuray has experience developing sensors for cancer, zoonotic diseases like bird flu, and environmental pollutants. When he received the letter about PFAS in his tap water, he started thinking about how to adapt his sensor platform to detect these prevalent contaminants.

Researchers like Basuray got interested in developing PFAS sensors because of contaminated drinking water in or near their homes. Many of them are now eager to commercialize their devices after the US Environmental Protection Agency’s proposal in March to set limits for six of the chemicals in drinking water. They have portable technology that can detect ultralow levels of PFAS in water, but most acknowledge that it will be a few more years before such devices are ready to hit the market.

Often called forever chemicals because they are slow to break down, PFAS are known for their ability to resist oil and water. They are found in many household products, including raincoats, nonstick frying pans, and fast-food packaging. Little is known about the health effects of most of the thousands of commercial PFAS, but a few of them are considered harmful at extremely low levels.

For two of the most toxic PFAS—perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)—the EPA proposed limits of 4 parts per trillion each in drinking water. The two chemicals are no longer used or produced in the US, but they contaminate drinking water throughout the country and worldwide.

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