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Detection of Salmonella by Surface Plasmon Resonance

View Article: PubMed Central

ABSTRACT

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.

No MeSH data available.


Sensograms showing: (a) Specific detection of Salmonella Enteritidis (3×109 cells mL−1) in spiked milk using antibody (O:9 detection antibody) against the O:9 antigen after capture from milk using the immobilised polyclonal anti-Salmonella antibody. (b) Cross-reactivity check using spiked milk containing Salmonella Enteritidis (3×109 cells mL−1) against O:4 detection antibody, which is specific for Salmonella Typhimurium. (c) SPR response to probing of uncontaminated milk (control) using the Salmonella Enteritidis specific O:9 detection antibody.
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f4-sensors-07-01427: Sensograms showing: (a) Specific detection of Salmonella Enteritidis (3×109 cells mL−1) in spiked milk using antibody (O:9 detection antibody) against the O:9 antigen after capture from milk using the immobilised polyclonal anti-Salmonella antibody. (b) Cross-reactivity check using spiked milk containing Salmonella Enteritidis (3×109 cells mL−1) against O:4 detection antibody, which is specific for Salmonella Typhimurium. (c) SPR response to probing of uncontaminated milk (control) using the Salmonella Enteritidis specific O:9 detection antibody.

Mentions: To test how the assay performs in a complex food matrix, milk spiked with the Salmonella serovars was used as a model system. Addition of milk spiked with Salmonella Typhimurium or Salmonella Enteritidis onto the sensor chip coated with polyclonal antibody resulted in an initial significant increase in the detection signal. This detection signal, however, was reduced after the subsequent washing step with PBS. The initial increase is attributed to bulk refractive index change of the sample medium due to the milk matrix. The detection signal due to capture of Salmonella Typhimurium (5×105 cells mL−1) using the polyclonal capture antibody was only 43 ± 4.5 AU (Fig. 3a). The corresponding detection signal due to the captured Salmonella Enteritidis (3×109 cells mL−1) from spiked milk using the polyclonal capture antibody was 75 ± 5.0 AU (Fig. 4a).


Detection of Salmonella by Surface Plasmon Resonance
Sensograms showing: (a) Specific detection of Salmonella Enteritidis (3×109 cells mL−1) in spiked milk using antibody (O:9 detection antibody) against the O:9 antigen after capture from milk using the immobilised polyclonal anti-Salmonella antibody. (b) Cross-reactivity check using spiked milk containing Salmonella Enteritidis (3×109 cells mL−1) against O:4 detection antibody, which is specific for Salmonella Typhimurium. (c) SPR response to probing of uncontaminated milk (control) using the Salmonella Enteritidis specific O:9 detection antibody.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3814861&req=5

f4-sensors-07-01427: Sensograms showing: (a) Specific detection of Salmonella Enteritidis (3×109 cells mL−1) in spiked milk using antibody (O:9 detection antibody) against the O:9 antigen after capture from milk using the immobilised polyclonal anti-Salmonella antibody. (b) Cross-reactivity check using spiked milk containing Salmonella Enteritidis (3×109 cells mL−1) against O:4 detection antibody, which is specific for Salmonella Typhimurium. (c) SPR response to probing of uncontaminated milk (control) using the Salmonella Enteritidis specific O:9 detection antibody.
Mentions: To test how the assay performs in a complex food matrix, milk spiked with the Salmonella serovars was used as a model system. Addition of milk spiked with Salmonella Typhimurium or Salmonella Enteritidis onto the sensor chip coated with polyclonal antibody resulted in an initial significant increase in the detection signal. This detection signal, however, was reduced after the subsequent washing step with PBS. The initial increase is attributed to bulk refractive index change of the sample medium due to the milk matrix. The detection signal due to capture of Salmonella Typhimurium (5×105 cells mL−1) using the polyclonal capture antibody was only 43 ± 4.5 AU (Fig. 3a). The corresponding detection signal due to the captured Salmonella Enteritidis (3×109 cells mL−1) from spiked milk using the polyclonal capture antibody was 75 ± 5.0 AU (Fig. 4a).

View Article: PubMed Central

ABSTRACT

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.

No MeSH data available.