Bringing PFAS Monitoring Home: An Integrated Magnetic Nanoparticle and Lateral Flow Assay System

PROJECT SUMMARY/ABSTRACT Per- and polyƲuoroalkyl substances (PFAS) are persistent environmental contaminants linked to severe health issues, including thyroid dysfunction, cancer, and developmental toxicity. Detected in the blood of 97% of Americans, PFAS exposure poses a critical public health challenge, prompting the EPA to establish stringent regulatory limits for their presence in drinking water. Current PFAS testing methods are prohibitively expensive, time- consuming, and difficult to interpret, creating an urgent need for a rapid, low-cost, and user-friendly solution. This project aims to develop the flrst at-home lateral Ʋow assay (LFA) for PFAS detection, offering a biologically relevant measure of thyroid hormone disruption caused by PFAS. The innovative approach leverages the competition between PFAS and thyroxine (T4) for binding to transthyretin (TTR), providing a toxicity index that correlates exposure with potential health impacts. To achieve sensitivity at the parts-per-trillion (ppt) level required by EPA standards, the test will integrate a novel magnetic nanoparticle pre-concentration method. Three speciflc aims will guide this work: (1) develop and optimize a lateral Ʋow assay utilizing T4-FITC and TTR protein to quantify PFAS concentrations as a function of thyroid hormone disruption, (2) create functionalized silica nanoparticles capable of achieving a 1000-fold PFAS concentration efficiency, and (3) reflne a nanoparticle elution buffer that is compatible with the TTR-T4 assay, enabling future integration into an at-home, user-friendly diagnostic device. The combined nanoparticle pre-concentration step and lateral Ʋow assay will be validated using water samples spiked with PFOA or PFAS at concentrations ranging from 1 ppt to 10 ppb, assessing sensitivity, performance, and dynamic range under realistic conditions. Phase I aims to establish proof-of-concept for a high- performance, accessible environmental diagnostic. Future Phase II efforts will focus on integrating the nanoparticle pre-concentration and lateral Ʋow assay into a single, scalable device optimized for affordability and use by non- experts. This project aligns with the mission of advancing public health through innovative diagnostic technologies, enabling consumers to monitor and mitigate PFAS exposure. Upon completion, this technology will redeflne environmental monitoring, enhance consumer health tools, and generate critical data linking PFAS exposure to health outcomes.