One-step, in-the-field detection of water contamination by unhealthy concentrations of Endocrine Disrupting Chemicals affecting Nuclear Receptors arrayed on a test strip

This SBIR Phase I project will develop and characterize 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 >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 that contain CECs at levels affecting the activity of CEC-Sensors built into each cell-based BioAssay. There are time and cost disadvantages for shipping water samples to central facilities that have the instrumentation and personnel infrastructure needed to conduct each BioAssay measurement. Each water sample also must be tested against multiple, distinct cell-based BioAssays which further impedes the economics of BioAssay monitoring. We propose 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 smart phone, 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. Such a product would have a far-reaching ENVORNMENTAL IMPACT. Phase I will define 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 will be 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 now used by the CA State Water Resources Control Board for cell-based BioAssay monitoring, which will allow 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 have a technical emphasis on expanding reliable, sensitive EDC detection to 20 Nuclear Receptor targets for different EDC classes. Strip printing, stability and storage, and the smart phone-based quantitative capture by in-the-field users also would be deliverables for Phase II. Overall, Phase I will create a method that, by the end of Phase II, will achieve a product to submit to the EPA’s Drinking Water Alternate Test Procedure Program for wide-spread use.