Detection of Salmonella by Surface Plasmon Resonance

This study explores the possibility of simultaneous and specific detection of Salmonella serovars by surface plasmon resonance (SPR). The Plasmonic® SPR device was used to develop this rapid assay. The sandwich immunoassay involves the use of a polyclonal anti-Salmonella antibody to simultaneous capture multiple Salmonella serovars present in a sample. This is followed by specific detection of the captured serovars using O-specific anti-Salmonella antibodies. Milk spiked with Salmonella Typhimurium and Salmonella Enteritidis was used as a model system to establish the assay. The assay was further extended to sequentially differentiate between the two Salmonella serovars on a single SPR chip in a single channel. The assay was proved to work without any additional dilution or clean-up steps. The sample volume requirement for the assay is only 10 μL. The lower limits of detection for Salmonella Typhimurium and Salmonella Enteritidis were 2.50×105 cells mL-1 and 2.50×108 cells mL-1, respectively