Rapid Detection of Escherichia coli O157:H7 Using Competitive Exchange of Fluorescent Surrogate Modified Surfaces in Liquid Media

A novel fluorescent surrogate based immunosensor is presented for use in remote detection of Escherichia coli O157:H7. A total of 3704 confirmed E. coli O157:H7 cases with a hospitalization rate of 46.5 % were reported by the Centers for Disease Control and Prevention in 2008. Rapid detection would aid in both prevention and water supply security. This report describes the successful generation of a sensor comprised of fluorescent surrogates with attachment to covalently immobilized antibodies. Fluorescence signal loss was seen upon live E. coli O157:H7 challenge. The 'acceleration' in signal decay detected a spiking event after 7 minutes with a detection threshold of 100 colony forming units per milliliter. The sensor surface was stable for 300 sampling times over a 5 hour period. This sensor design is adaptable for integration into remote sensing type systems due to the small size, low power requirements and stability. [PUBLICATION ABSTRACT]