"We developed and optimized a detection method using an antibody-coupled fiber optic biosensor for the simultaneous detection of L. monocytogenes, E. coli O157:H7, and S. Enteritidis."

Optical biosensors for food pathogen detection

Investigator: Arun K. Bhunia (Department of Food Science)

Project Report 2008 - 2009

» Download Project Report 2008 - 2009

Project Rationale

In this project, our ultimate goal was to develop a sensitive fiber optic-based sensor for the concurrent detection of multiple foodborne pathogens, including Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica serovar Enteritidis in a single food sample. In previous work, we were able to develop separate fiber optic sensor-based assays specific for each target pathogen: L. monocytogenes, E. coli O157:H7, and S. Enteritidis. During this project cycle, our goal was to optimize the fiber optic biosensor platform for the simultaneous detection of all three pathogens in a single assay format. This will not only reduce the cost per test, but will also ensure product safety with regards to the three key pathogens.

Project Objectives

  • Develop and evaluate an antibody-coupled fiber optic biosensor (ANALYTE 2000™) for detecting L. monocytogenes
  • Validate the multiplex fiber optic sensor with inoculated ready-to-eat (RTE) shredded beef, chicken and turkey meat.

Project Highlights

We developed and optimized a detection method using an antibody-coupled fiber optic biosensor (ANALYTE 2000™) for the simultaneous detection of L. monocytogenes, E. coli O157:H7, and S. Enteritidis. For the capture of each bacterium, a biotinylated polyclonal antibody was immobilized on the fiber. We labeled each bacterium-specific monoclonal antibody with Alexa Fluor 647 and used it as a reporter antibody. The biosensor detected L. monocytogenes, E. coli O157:H7, and Salmonella Enteritidis. The limit of detection was found to be 103-104 CFU/ml in pure cultures and in mixed culture conditions when inoculated into RTE meat such as beef, chicken, and turkey, which were enriched in a selective enrichment broth for Salmonella, Escherichia, and Listeria., E. coli O157:H7, and S. Enteritidis.