Direct detection of E. Coli O157:H7 in selected food systems by a surface plasmon resonance biosensor

John Waswa, Joseph Irudayaraj, Chitrita DebRoy

Research output: Contribution to journalReview article

Abstract

The SpreetaTM, surface plasmon resonance (SPR)-based biosensor, was used to detect Escherichia coli O157:H7 spiked in milk, apple juice and ground beef extract using specific antibodies. In the SpreetaTM biosensor light from an LED is reflected off a gold surface, and the angle and intensity corresponding to the SPR minimum is measured and represented as a refractive index (RI) change corresponding to the antigen-antibody coupling at the sensor surface. Milk, apple juice, and ground beef patties spiked with E. coli O157:H7, at varying concentrations, were injected on the sensor surface immobilized with antibodies against the pathogen at a rate of 1 ml/min for a total of 2 min. The change in RI due to the binding of O157:H7 corresponding to each concentration was computed as an average of three replications over a 2 min interaction period. Assays were conducted at near real-time and results obtained after about 30 min of sample injection. Sensitivity of the E. coli O157:H7 assay was 102-103 colony forming unit (CFU)/ml. The biosensor assay was also specific to E. coli O157:H7 as other organisms (E. coli K12 and Shigella) did not produce any appreciable change in the sensogram. Further experiments are needed to establish well-defined methods for detecting other food-borne pathogens in more complex and specific food matrices.

Original languageEnglish (US)
Pages (from-to)187-192
Number of pages6
JournalLWT - Food Science and Technology
Volume40
Issue number2
DOIs
StatePublished - Mar 1 2007
Externally publishedYes

Fingerprint

surface plasmon resonance
Escherichia coli O157
Surface Plasmon Resonance
biosensors
Biosensing Techniques
Food
Refractometry
refractive index
ground beef
apple juice
Malus
antibodies
sensors (equipment)
Milk
assays
beef extracts
Immobilized Antibodies
Escherichia coli K12
milk
Shigella

Keywords

  • Escherichia coli O157:H7
  • Food safety
  • Spreeta biosensor
  • Surface plasmon resonance

ASJC Scopus subject areas

  • Food Science

Cite this

Direct detection of E. Coli O157:H7 in selected food systems by a surface plasmon resonance biosensor. / Waswa, John; Irudayaraj, Joseph; DebRoy, Chitrita.

In: LWT - Food Science and Technology, Vol. 40, No. 2, 01.03.2007, p. 187-192.

Research output: Contribution to journalReview article

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