Locust neurons detect PFAS at environmental levels, suggesting portable sensors

Researchers at Michigan State University have discovered that neurons in a locust's brain can distinguish among multiple per- and polyfluoroalkyl substances (PFAS) at concentrations relevant to environmental contamination. PFAS, used in products such as nonstick cookware, waterproof fabrics and firefighting foams, persist in water, soil and living organisms, making them difficult to monitor with current laboratory-based methods.

The team recorded neural activity from the locust's olfactory brain region while exposing the insects to gases containing several PFAS compounds, including PFOS, one of the most common and heavily regulated PFAS chemicals. Each compound produced a distinct pattern of neural activity — an "odor fingerprint" — allowing the insects to differentiate between them.

Lead author Summer McLane-Svoboda, a doctoral candidate, said the researchers were uncertain whether the locust brain would respond to PFAS at all. The clear, compound-specific signals indicated that biological sensory systems could serve as a detection platform for these human-made chemicals.

Associate professor Debajit Saha noted surprise at the strength of the neural response, given that PFAS have existed in the environment for only decades and have no natural evolutionary precedent for insects. The locusts detected PFOS at concentrations similar to those found in contaminated environmental samples.

Current PFAS detection typically relies on liquid chromatography-mass spectrometry, which is accurate but expensive, requires specialized facilities and is not easily deployed in the field. Many existing methods also target specific compounds, complicating broad screening.

The study, published in the Journal of Hazardous Materials Advances, serves as a proof of concept. The researchers are now testing environmental water samples collected in Michigan to evaluate whether the approach works outside the laboratory.

The long-term goal is to miniaturize the technology into portable biological sensors capable of rapidly screening multiple PFAS compounds in field settings. Saha said biology may offer a fundamentally different way to detect PFAS, potentially enabling faster and more versatile contamination monitoring.