DETECTION OF E. COLI O157:H7 USING A MINIATURIZED SURFACE PLASMON RESONANCE BIOSENSOR

Abstract

A commercially available Spreeta sensor was adapted into a surface plasmon resonance (SPR) biosensor to detectEscherichia coli O157:H7. The SPR biosensor couples antibody-antigen reactions with signal generation, using Kretschmanngeometry to couple light into surface plasmons. The objectives of this study were to test the feasibility of adapting aminiaturized integrated SPR liquid sensing system into a biosensor to detect E. coli O157:H7 in laboratory cultures and totest its sensitivity and specificity. Experiments were conducted at near real-time with results obtained for one SPR biosensorassay within 35 min. The limit of detection for E. coli O157:H7 was determined to be 8.7 106 CFU/mL. In mixed cultures,the detection limit of the biosensor was 107 CFU/mL for E. coli O157:H7 when the non-target bacterial concentration was106 CFU/mL or less. Concentrations of non-target bacteria beyond 107 CFU/mL caused a decrease in the magnitude of thesensor response. The results of this study demonstrate the potential for employing the SPR biosensor to detect E. coli O157:H7in near real-time. The SPR biosensor shows potential as a tool to assist the food industry in pathogen monitoring that is quickand specific. Due to its portability, it can potentially be incorporated into a HACCP protocol in the food industry.