Portable Nanowire Platform for Quasi Real-Time and Ultrasensitive Detection of Microbes

Rapid, simple and inexpensive molecular on-site diagnostics for the detection of classes of microbes are essential for the bioremediation community. The sophisticated techniques currently used for detection of microbial activity in submerged soils and aquatic sediments can be labor intensive and technically difficult. In addition, the expense of these approaches can discourage the series of measurements over time required for relating microbial activity to seasonal changes or environmental disturbances—thus limiting the value of such tests. This project’s portable nanomaterial-based sensor will quantitatively detect subsurface microbes on site with minimal user training. General statement of how the problem is being addressed: The project team is developing a sensitive nanomaterial-based microbial monitor that will detect biomarkers indicative of key metabolic functions of Geobacter species specific to the Rifle site and Berkeley Lab’s East River, Colorado research watershed. The envisioned sensor would have a disposable sensor chip that could be used with a portable hand-held unit for data acquisition, processing and read-out. What was done in Phase I: In Phase I, the team developed a working model that was validated with chemostat cultures of Geobacter. The sensors detected femtomolar levels of the metabolic proteins specific to Geobacter within 30 minutes. An unambiguous sensor response was seen for the target metabolic protein biomarkers amongst approximately 3000 other proteins with minimal cross- reactivity. What is planned for the Phase II: In Phase II, we will further test, evaluate and refine the sensor prototype to target general guidance on microbial processes in the sites of interest. Advances in Phase II will expand the monitor to include enzymes catalyzing methane production and sulfate reduction. We will also develop reader housing and software to support sensor data acquisition and display. Commercial applications and other benefits: The underlying technology has the capacity to detect a wide array of microbes and microbial functions in situ and in real time. Thus, this sensor device will support the approximately $7B United States remediation market, driven by needs of the Department of Energy, Department of Defense, Resources Conservation and Recovery Act, superfund sites, and others.