Development of a Simultaneous Detection Method for Foodborne Pathogens Using Surface Plasmon Resonance Biosensors

Surface plasmon resonance (SPR) biosensors were used to develop a rapid and simultaneous detection method for three important foodborne pathogens, i.e., Escherichia coli O157:H7 (0157), Salmonella Enteritidis (SE), and Listeria monocytogenes (LM). Bacterial homogenates prepared by sonication from bacterial suspensions at various cell concentrations were analyzed using SPR biosensors and sensor chips with polyclonal antibodies specific to each of the target pathogens. The precipitates from the homogenates were demonstrated to be suitable for specific and simultaneous detection of O157, SE, and LM. By using the precipitates and a custom-built multichannel SPR biosensor, the lower detection limit for O157, SE, and LM was determined to be 0.6 x 10(6), 1.8 x 10(6), and 0.7 x 10(7) CFU/mL, respectively, in the presence of non-target pathogens at concentrations of 10(5) to 10(8) CFU/mL.