New portable device enables fast and accurate detection of PFAS in water

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals known for their exceptional resistance to degradation, earning them the nickname "forever chemicals." These persistent substances can accumulate in water, soil, and living organisms, raising growing concerns about their potential impacts on human health and the environment.

Detecting PFAS contamination is a critical first step toward addressing these risks. However, conventional PFAS analysis typically requires collecting environmental samples and transporting them to specialized laboratories equipped with advanced mass spectrometry instruments. Although highly sensitive and accurate, these methods can be costly and time-consuming.

Researchers from the Micro/Bio/Nanofluidics Unit at the Okinawa Institute of Science and Technology (OIST) have now created a reliable, easy-to-mass-produce platform that enables regulators and other environmental actors to detect PFAS on the spot without the need for an external lab.

Our goal is to develop a sensitive, low-cost technology that can eventually be used outside specialized laboratories. We have demonstrated that it works for PFOA and PFOS, and the same platform could potentially be adapted to detect other PFAS compounds."

Dr. Mark Sullivan, Micro/Bio/Nanofluidics, Okinawa Institute of Science and Technology Graduate University

The new device is described in Biosensors and Bioelectronics.

Catching PFAS with synthetic antibodies and electrical currents

The researchers have designed a new class of molecularly imprinted polymers, or MIPs, that are perfectly tailored to fit PFAS. The materials are formed around the target molecule - in this case, PFAS - creating a binding site. The target molecule is then washed away, leaving behind a material that recognizes and captures the target again, like a lock that is perfectly shaped for a key. This is also why MIPs are often called 'synthetic antibodies.'

Their device detects PFAS by measuring changes in electrical current as target molecules bind to a sensor coated with PFAS-specific MIPs. The greater the change in electrical current, the higher the PFAS concentration is in the water sample. Because the measurement requires no additional chemical reagents, this approach could provide a simpler, lower-cost solution for portable, on-site water monitoring.

The platform is compact, low-cost, and designed for easy manufacturing. For the prototype, the researchers screen-printed 100 disposable electrodes onto repurposed fabric in just a few hours. These were then coated with PFAS-specific MIPs and connected to commercially available potentiostats, which measure electrical signals and can plug directly into a smartphone or laptop. Furthermore, the MIP manufacturing method is modular, meaning the target molecule can be replaced with any member of the PFAS family; for this prototype, the researchers chose the two most common PFAS chemicals with documented health risks: PFOS and PFOA.

Strengthening the global environmental immune defense against forever chemicals

PFAS have proven to be an insidious problem for the environment and health due to two key factors: their exceptional resistance to heat, water, oil, and environmental degradation makes them both useful and extremely difficult to break down; and their diversity, with the PFAS family encompassing more than 10,000 similar chemicals, of which 50-150 members are regulated across the globe.

The team's MIP platform's modularity makes it relatively simple to adapt it to different PFAS molecules and, more importantly, lowers the barrier to addressing PFAS contamination going forward.

Dr. Perrine Lasserre continues: "It shows that it's possible to make a detection system that empowers local agencies or even families to make an informed decision about whether and how to address potential PFAS contamination - such as alerting municipal authorities to contamination at specific sites, or whether to invest in a water filter. Whatever we can achieve with this system is going to be beneficial."

"Accurate and accessible detection is an important step toward addressing PFAS contamination," says Professor Amy Shen. "Our study demonstrates how synthetic molecular recognition can be combined with low-cost electrochemical devices to detect extremely small concentrations of these persistent chemicals. While further development and field validation are needed, we see considerable potential for making environmental monitoring more accessible and widely available."