A Microfluidic Biosensor Platform for Real-Time Water Monitoring

Access to clean, reliable water supplies is critical to our quality of life and our economy, yet across the country thousands of hazardous waste sites are so heavily contaminated that the underlying groundwater doesn’t meet drinking water standards. Measuring contamination in the environment is critical to human health and to the DOE Biological and Environmental Research (BER) program’s goal to understand complex subsurface systems, but current testing is mostly limited to sporadic sample collection for laboratory analysis. Not only is this process costly, but it is inefficient, making it difficult to monitor groundwater with high spatial or temporal resolution. As a result, current methods do not capture the full complexity of how contaminants fluctuate in the environment and do not enable real-time decision making or process control. We have developed a customizable in-line biosensor platform that uses a microfluidic cartridge to house many different sensor strains, each with the ability to detect a different water contaminant on a continuous basis. Each strain fluoresces when its specific target is present in the water, and we have engineered a customized optics and image processing platform that translates these cell signals into quantitative information about contaminant concentration. Each cartridge can take continuous data for at least a month with no intervention, and data can be transmitted remotely to a user-friendly interface. In Phase I, we demonstrated technical feasibility by developing and characterizing new sensor strains for nitrate, nitrite, ammonium, and phosphate, and we used our microfluidic plat- form to collect hundreds of hours of calibration data to refine computational tools to correlate fluorescence signals with contaminant levels. In Phase II, we engineered additional sensing strains to address the needs of customers, developed a sophisticated software platform for data analysis and remote data access, and performed two real-world deployments in outdoor environments to demonstrate the enhanced robustness of our sensor. In Phase IIB, we will build upon our success in Phase II to perform several Objectives geared toward achieving commercialization of our plat- form. Our two-year work plan will ready us for market entry by developing and demonstrating platform readiness for customer use, acquiring validation data at both government and customer sites, and developing and implementing a mass-manufacturing plan. In terms of broad marketability, there is a critical need for novel in-water nutrient sensors in wastewater, agricultural, and environmental monitoring settings. In addition to working with an academic research group to demonstrate the benefits of our sensor for environmental monitoring, we are partnering with two commercial partners to demonstrate the ability of our sensor to tie into process control systems to optimize their operations and boost revenues. Ultimately, our goal is to develop sensing technology that is not only marketable but that provides a broader public benefit. The nation’s groundwater resources face many serious threats including industrial waste, agricultural runoff, sewage, and toxic chemicals used in processes like fracking. An advanced sensor that addresses current limitations would allow monitoring to become more affordable, continuous, and field-deployable. Therefore, not only will our biosensor platform be highly marketable to a wide range of end-users, it will meet the increasing need for data to address the increasing public awareness of the health risks associated with contaminated drinking water.