Fabrication and evaluation of an electrical immunoassay biosensor for the rapid detection of foodborne pathogens in food and water

The thesis describes the development of an electrical immunoassay (EI) biosensor for detecting foodborne pathogens. The biosensor consists of two components: an immunosensor that is based on an electrical sandwich immunoassay and a reader for signal measurement. The architecture of the immunosensor utilizes the lateral flow format, which allows the movement of fluid from one region to another by capillary action. The biosensor provides a specific, sensitive, low volume, and real-time detection strategy. Results show that the biosensor can detect approximately 8 × 101 colony-forming units (CFU) per ml in 6 minutes. Results are presented to highlight the performance of the biosensor for detecting enterohemorrhagic Escherichia coli and Salmonella species in food and water samples. The ability to change the specificity of the antibodies will enable the biosensor to be used as a detection device for other types of foodborne pathogens. Such a device can be used to enhance food safety and biosecurity of the food supply and can also be adapted for use in medical diagnostics and bio-defense.