Locust neurons detect PFAS at environmentally relevant levels, pointing to portable sensors

Researchers at Michigan State University have found that locust brain neurons can identify various PFAS chemicals, including PFOS, at environmentally relevant concentrations. PFAS, or per- and polyfluoroalkyl substances, are commonly used in products like nonstick cookware and firefighting foams, and are notoriously difficult to detect due to their slow breakdown.

Debajit Saha, an associate professor, stated that there is a significant need for technologies capable of identifying these chemicals at low concentrations. Although insects, such as dogs, are known for their chemical detection abilities, scientists have struggled to create artificial sensors that match the sensitivity of living organisms.

To investigate this, researchers recorded neural activity from a locust's brain that processes odors while exposing the insects to gases containing multiple PFAS compounds. They discovered that each compound produced a unique neural activity pattern, or "odor fingerprint," enabling the insects to distinguish between different chemicals.

Notably, the locusts could detect PFOS at concentrations comparable to those found in contaminated environmental samples. This finding surprised researchers as PFAS are entirely human-made chemicals, having only existed for decades. The team hypothesizes that the insect's sensory system can detect these unnatural substances, despite them not naturally occurring in the environment.

Current PFAS detection methods typically involve laboratory instruments like liquid chromatography-mass spectrometry, which are expensive and not easily deployable in the field. The study serves as a proof of concept, and the team is now testing the approach using environmental water samples collected in Michigan. Ultimately, they aim to miniaturize the technology into portable biological sensors that can rapidly screen for multiple PFAS compounds in the field, offering a new way to monitor contamination through living sensory systems.