Biosensors Research

Guild BioSciences has pioneered biosensor research to improve the speed and accuracy of bacterial pathogen detection. In recent work, Guild BioSciences has successfully introduced bioluminescent genes into reporter bacteriophages. When the bacteriophages infect the target organism, light is emitted by the infected organism, which gives positive indication that the target organism is both present and viable. This light can be detected by standard light measurement equipment and, in some instances, the human eye. The application of this technology to bacterial pathogen detection has significant potential as a phytopathogen diagnostic (to limit the impact of crop disease) or in detecting biowarfare bacteria. Ultimately, a product that can be utilized for quick and accurate anthrax or plague diagnosis will be developed using this technology.

This method has specific advantages over conventional sensing techniques:

Guild BioSciences has received grants from NIH, USDA and NSF to develop biosensors for the following:

Guild BioSciences is in the early stages of developing solid state sensors based on electrochemical principles to sense bacteria. In an aqueous solution, charge is carried between electrodes by ions in the solution. The presence of particulate matter (such as pathogens) physically obstructs the movement of these charge-carrying ions, leading to changes in solution impedance. Depending on the type of microbe, the impedance response can be Faradaic, purely capacitive, or a mixture of the two, providing information on the cell density, growth, and long-term behavior of cells in the solution. Likewise, microbes can adhere to one another or to the electrode surfaces, producing measurable changes in the interfacial impedance. The presence of intact cell membranes on the electrodes and their distance to the electrodes determine the current flow and thus the sensor signal, providing information on spatial spreading, attachment, and morphology of the sampled cells. Using specific electrochemical impedance properties of the microbes and their dependence on measurement parameters, the biosensor can provide a unique and recognizable signature with high selectivity and sensitivity, and a detection range between 1×10¹ and 1×10⁸ CFU/ml.

Want to know more? This video explains the details of the Bacillus anthracis reporter bacteriophage.

Guild BioSciences is always interested in extending this research through collaboration, exploring new or non-traditional opportunities, and developing marketable products. Please contact us to explore ways in which we can work together.

Listed below are the abstracts and links to biosensor publications and conference presentations made by Guild BioSciences scientists.

Schofield, D.A., Molineux, I.J. and Westwater, C. 2011. Bioluminescent reporter phage for the detection of category A bacterial pathogens. http://www.jove.com/details.php?id=2740 doi: 10.3791/2740. Journal of Visualized Experiments, 53.

Smiechowski, M.F., Lvovich, V.F., Srikanthan, S., Silverstein, R.L. 2011. Non-linear impedance characterization of blood cells-derived microparticle biomarkers suspensions. Electrochimica Acta, 56: 7763-7771.

Schofield, D.A., Molineux, I., and Westwater, C. 2011. Anthrax and plague diagnostic identification, and antibiotic susceptibility testing using bioluminescent reporter phage. 9th ASM Biodefense and Emerging Diseases Research Meeting, Washington, DC, February 6th-9th, 2011.

Schofield, D.A., Molineux, I.J., and Westwater, C. 2009. Diagnostic bioluminescent phage for the detection of Yersinia pestis. Journal of Clinical Microbiology, 47(12):3887-94.

Schofield, D.A. and Westwater, C. 2009. Phage-mediated bioluminescent detection of Bacillus anthracis. Journal of Applied Microbiology, 107(5):1468-78.