Superfund Research Program
One-Step, In-the-Field Detection of Water Contamination by Unhealthy Concentrations of Endocrine Disrupting Chemicals Affecting Nuclear Receptors Arrayed on a Test Strip
Project Leader: Fred Schaufele
Grant Number: R43ES036903
Funding Period: Phase I: August 2024 - July 2025
Summary
This SBIR Phase I project develops and characterizes components for an 'in-the-field' test strip to detect chemical pollutants in drinking water. The US Safe Drinking Water Act (SDWA) establishes the methods and frequency of water monitoring for drinking water procurement. Currently, over 90 contaminants (microorganisms, disinfectants and byproducts, inorganic and organic chemicals, radionuclides) are mandated for measurement, and another 80 are under active investigation for future inclusion. However, just on the chemical side, 100,000 "contaminants of emerging concern" (CECs) have been identified.
To broaden monitoring to all chemical CECs, some water authorities have started using 'BioAssays' as a chemically-agnostic survey for water samples containing CECs at levels affecting the activity of CEC-Sensors built into each cell-based BioAssay. There are time and cost disadvantages to shipping water samples to central facilities with the instrumentation and personnel infrastructure needed to conduct each BioAssay measurement. Each water sample must also be tested against multiple, distinct cell-based BioAssays, which further impedes the economics of BioAssay monitoring.
The research team proposes to develop a hand-held, BioAssay-like CEC-Sensor 'Strip.' By the end of Phase II, a 1 x 1.5 cm Detection Strip printed with 20 physiologically relevant Sensor proteins and captured by a smartphone would permit field determination of water samples containing CECs at concentrations affecting Sensor activity. Although the chemical identity of any contaminant would not be known, the unique activity signature across 20 Sensor proteins and the field-accessible low-cost product would permit the rapid tracking of a chemically unknown contaminant to its source, providing far-reaching environmental impact.
Phase I defines the technical feasibility of the Sensor Strip approach. A common detection protocol will be optimized for two pilot Nuclear Receptors Sensors of Endocrine Disrupting Chemicals (EDCs) of high concern. Go/No Go milestones are based on Receptor activation at the lowest concentration of natural Receptor ligands normally present in the body; thus, EDCs at physiologically meaningful levels, or less, will be detectable. The Receptors chosen include one currently used by the CA State Water Resources Control Board for cell-based BioAssay monitoring, allowing comparison of the in-field product with current practices. The in vitro detection method developed in Phase I will be generalizable to all Nuclear Receptors.
If Phase I sensitivity, specificity, and reproducibility milestones are achieved, Phase II will focus on expanding reliable, sensitive EDC detection to 20 Nuclear Receptor targets for different EDC classes. Strip printing, stability and storage, and smartphone-based quantitative capture by in-the-field users will also be deliverables for Phase II. Overall, Phase I creates a method that, by the end of Phase II, will result in a product ready for submission to the EPA's Drinking Water Alternate Test Procedure Program for widespread use.