E. coli-based Chemical and Biological Agent Detection

In collaboration with the Hebrew University of Jerusalem, Israel

With the heightened threat of chemical and biological agents and increased concern about environmental pollutants, there is a significant need for fast and accurate detection devices such as cell-based toxicity sensors. Such systems can be tailored to detect general or specific toxicants, or to monitor chemical and environmental stressors that impact human homeostasis. For example, there are known human toxins that induce a physiological response such as a change in protein production or electrical activity of neurons. Due to their large populations, relatively inexpensive costs, high sensitivity and rapid responses, bacteria are of particular interest for use in cell-based sensors. Further, with our continuously expanding understanding of functional genomics and signaling mechanisms of many bacterial systems, it is likely that microbial whole-cell biosensors could become an important detection tool for future environmental, industrial, medical, military or homeland defense applications.

Figure 1. Functional E. coli deposited by BioLP™ in a 100 micron diameter spot. Green fluorescent protein expressed by the E. coli is used as a reporter for bioagents.

In order for cell-based biosensors to be effective as analytical testing devices, it is necessary that viable cells are incorporated into the hardware platform that will house them; the deposition of the cells should be compatible with high-throughput industrial processes, with high and reproducible accuracy. We have developed a technique, Biological Laser Printing or BioLP™, which satisfies these requirements and has advantages over current technologies. BioLP™ is capable of rapidly depositing patterns of active biomolecules and living cells onto a variety of material surfaces. Unlike ink jet or manual spotting techniques, this process delivers small volume (nL to fL’s) aliquots of biomaterials without the use of an orifice, thus eliminating potential clogging issues and enabling diverse classes of biomaterials to be deposited. We are using this laser-based printing method to transfer genetically-modified bacteria onto an optical biosensor platform. The BioLP™ technology enables smaller spot sizes, increased resolution, and improved reproducibility compared to related technologies. In addition, we are working to use this printer to deposit dried and stabilized bacteria onto sensing platforms, enabling extended shelf lives without refrigeration.