Per- and polyfluoroalkyl substances (PFAS) are a pervasive class of contaminants, now found from Antarctic ecosystems to human blood, and their exceptional stability and long biological half-lives mean the risk cannot simply be eliminated, it must be monitored and mitigated over time through widespread testing and targeted remediation. The current gold-standard assay, LC–MS/MS, is costly, slow, and largely confined to specialized central laboratories, underscoring the need for an affordable, field-ready, and user-friendly PFAS detector. In this presentation, I will introduce a protein-based electrochemical platform for point-of-need measurement of perfluorooctanoic acid (PFOA), a commonly regulated PFAS. By combining lubricin (proteoglycan 4) with a methylene-blue–tagged human liver fatty acid–binding protein (FABP1-MB), the sensor reports PFOA at 0.41 ng/L and 0.41 µg/L, respectively. I will also present our initial performance validation in real water and whole-blood samples, highlighting potential applications in both environmental surveillance and clinical monitoring.