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

In situ detection of microbial activity in submerged soils and aquatic sediments can be labor intensive and technically difficult, especially in dynamic environments where data on microbial status is desired. Current approaches for estimating anaerobic microbial activity involve incubating soil/sediment samples. Sophisticated analytical techniques are currently used which are not convenient and sometimes unsuitable for field deployment. Also, the labor and expense of such approaches often discourage the series of measurements over time required for relating microbial activity to seasonal changes or environmental disturbances including introduction of contaminants. This project’s portable nanowire platform will quantitatively detect subsurface microbes in situ using a handheld reader with minimal user training. The project team will develop a biosensor with antibody (Ab) functionalized nanowires for in situ monitoring of microbes in subsurface environments. The sensor system will incorporate capture, detection, and response/readout technology. Unlike current technologies used for microbe detection, this system eliminates the need for culture-based microbial growth, the addition of extraneous fluorophores, use of enzymatic signal amplification or complicated experimental set up and data read out. In Phase I, the project team will: (1) fabricate multiplex electrode biosensor arrays, (2) construct antibody-grafted polymer nanowire biosensor, (3) prepare chemostat growth cultures of Geobacter and isolate the proteins, and (4) demonstrate feasibility with a Phase I working model. The result will be a compact, field-deployable rugged sensor with in situ monitoring capacity for rapid and sensitive detection of subsurface microbial presence. This multiplexed biosensor is initially being developed with the aim of detecting Geobacter, but it can be easily modified for detection of other microbes depending on the need. Commercial applications and other benefits: The underlying technology has the capacity to detect a wide array of pathogens in situ and in real time. The global environmental monitoring market is poised to grow at a compound annual growth rate of 7.5% between 2015 and 2020, and is expected to reach a value of ~$20.5 Billion by 2020.