Rapid detection of Salmonella Enteritidis and Escherichia coli using surface plasmon resonance biosensor.

摘要

The Biacore surface plasmon resonance (SPR)-based biosensor was used to detect Salmonella enterica serovar Enteritidis and E. coli in spiked skim milk using specific antibodies. The optical SPR biosensor registers changes in the refractive index binding of the analyte (bacteria) to the ligand (antibody) on the gold-coated sensor chip surface. Immobilized protein A-captured specific antibodies were used to detect the bacteria in less than an hour. The reaction was found to be specific, and the limits of detection of the assay were found to be 25 cfu/ml for E. coli and 23 cfu/ml for Salmonella. The findings indicate that the antibody-prepared biosensor was specific to the target of interest, and non cross-reactive to the nontarget bacteria with high specificity comparable with that of the fibre-optic biosensor. The results demonstrate the potential of using the SPR-based Biacore biosensor for the detection of E. coli and Salmonella in foods such as milk. The biosensor is sensitive, specific, and rapid allowing real-time detection of the pathogens..