Point-of-Need PFAS Detection: A Yes/No Biosensor Solution

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) pose one of the world's most prominent chemical health threats and are detected in virtually everything from the Antarctic environment to human blood. Due to the extreme half-lives and omnipresent distribution of the chemical class, the threat cannot be eliminated but rather must be continuously monitored and managed through widespread sample testing and targeted remediation long term. Unfortunately, the current standard detection method, liquid chromatography/tandem mass spectrometry (LC/MS/MS), is expensive, time-consuming, and limited to use by highly trained professionals in centralized laboratories. For this reason, there is an urgent need for a field-deployable, affordable, and easy-to-use device for PFAS detection. This paper addresses the issue with a protein-based electrochemical sensor for the point-of-need detection of perfluorooctanoic acid (PFOA), which is one commonly regulated PFAS compound of particular concern. Using two proteins, lubricin (LUB, proteoglycan 4) and human liver fatty acid binding protein engineered with a methylene blue redox tag (FABP1-MB), a response to PFOA is detected at 0.41 ng/L and 0.41 μg/L concentrations. Detection of PFOA is also demonstrated in real water and whole blood samples, demonstrating the sensors' possible future application for both environmental and biomedical monitoring.