EAGER: Inexpensive and Rapid Detection of Per- and Polyfluoalkyl Substances in Drinking Water Supplies Using Macrocycle-Functionalized Gold Nanoparticles

Per- and polyfluoroalkyl substances (PFAS) consist of over 4,000 synthetic chemicals that are used in the manufacturing of a variety products including non-stick cookware, food wrappers, and fire-fighting foams. PFAS are commonly referred to as "forever chemicals" because they are extremely difficult to break down and become persistent once released into the environment.

PFAS have emerged as contaminants of great concern for human and ecosystem health due to their toxicity, mobility, and high tendency to accumulate in environmental media (e.g., soils and water) and living organisms and plants. One of the major routes for human exposure to PFAS is via the ingestion of drinking tap water. However, current analytical assays and tools used to measure PFAS concentrations in water (e.g., sample preconcentration followed by liquid chromatography and mass spectrometry) are expensive, time-consuming, and restricted to specialized laboratories.

The goal of this high-risk high-reward EAGER project is to develop a novel analytical tool for the inexpensive and rapid detection and quantification of PFAS in water samples based on a new Surface Enhanced Raman Spectroscopy (SERS) platform. The successful completion this project could lead to the development and validation of a rapid, cost effective and more efficient analytical tool to detect and quantify PFAS in drinking water sources.

Further benefits to society will be achieved through student education and training including the mentoring of one doctoral student and two undergraduate students.

Chronic exposure to PFAS through the ingestion of drinking water has become a global health concern. The overarching goal of this high-risk high-reward EAGER project is to develop an inexpensive and robust method to quantify PFAS in drinking water. To advance this goal, the Principal Investigators (PIs) propose to leverage and integrate recent advances in plasmonics and supramolecular chemistry to 1) extract and concentrate PFAS molecules from water samples onto macrocycles (MCs) functionalized gold (Au) nanoparticles (NPs) immobilized within a bacterial cellulose (BC) matrix, and 2) use laser illumination to excite the PFAS laden MC functionalized Au NPs to generate hot-spot normalized surface-enhanced Raman spectra.

The collected Raman spectra are subsequently analyzed by an optical spectrometer to identify the extracted PFAS molecules and estimate their concentration in the tested water samples. To validate their new analytical method, the PIs propose to investigate PFAS detection and quantification under environmentally relevant conditions including in the presence of dissolved organic matter.

The successful completion of this project could lead to the development of a compact and modular device for rapid and onsite PFAS quantification in drinking water supplies. Ultimately, the PIs hope that their new analytic approach could shift the liquid chromatography-tandem mass spectrometry-based paradigm currently used by government and industry to monitor the contamination of drinking water sources by PFAS.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.