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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.


SPR sensograms showing sequential detection of Salmonella serovars spiked in milk: (a) Salmonella Typhimurium (O:4 detection antibody) followed by Salmonella Enteritidis (O:9 detection antibody). (b) Salmonella Enteritidis (O:9 detection antibody) followed by Salmonella Typhimurium (O:4 detection antibody).
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f7-sensors-07-01427: SPR sensograms showing sequential detection of Salmonella serovars spiked in milk: (a) Salmonella Typhimurium (O:4 detection antibody) followed by Salmonella Enteritidis (O:9 detection antibody). (b) Salmonella Enteritidis (O:9 detection antibody) followed by Salmonella Typhimurium (O:4 detection antibody).

Mentions: As it was already established that neither the serovars nor the detection antibodies interfere with the SPR detection process when present together in a mixture, further experiments were carried out to evaluate the possibility of detecting both the serovars, using a single SPR channel in a sequential manner. In the sequential detection mode, the addition of the milk sample containing the mixture of both the Salmonella serovars (5×105 cells mL−1 of Salmonella Typhimurium and 3×109 cells mL−1 of Salmonella Enteritidis) onto the sensor chip was then probed with either O:4 or O:9 detection antibody, followed by O:9 or O:4 detection antibody. The first detection signals were comparable to that obtained in the multi-channel detection mode. The average value of the detection signal for Salmonella Typhimurium in the mixture when probed with O:4 detection antibody first was 66 ± 3.2 AU (Fig. 7a). The corresponding detection signal for Salmonella Enteritidis in the mixture when O:9 detection antibody was the first antibody was 60 ± 6.7 AU (Fig. 7b). The detection signal for Salmonella Typhimurium when detected in the second place (O:4 detection antibody) was 40 ±7.8 AU (Fig. 7b), and the corresponding detection signal for Salmonella Enteritidis detected secondly (O:9 detection antibody) was 28 ± 5.7 AU (Fig. 7a).


Detection of Salmonella by Surface Plasmon Resonance
SPR sensograms showing sequential detection of Salmonella serovars spiked in milk: (a) Salmonella Typhimurium (O:4 detection antibody) followed by Salmonella Enteritidis (O:9 detection antibody). (b) Salmonella Enteritidis (O:9 detection antibody) followed by Salmonella Typhimurium (O:4 detection antibody).
© Copyright Policy
Related In: Results  -  Collection

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

f7-sensors-07-01427: SPR sensograms showing sequential detection of Salmonella serovars spiked in milk: (a) Salmonella Typhimurium (O:4 detection antibody) followed by Salmonella Enteritidis (O:9 detection antibody). (b) Salmonella Enteritidis (O:9 detection antibody) followed by Salmonella Typhimurium (O:4 detection antibody).
Mentions: As it was already established that neither the serovars nor the detection antibodies interfere with the SPR detection process when present together in a mixture, further experiments were carried out to evaluate the possibility of detecting both the serovars, using a single SPR channel in a sequential manner. In the sequential detection mode, the addition of the milk sample containing the mixture of both the Salmonella serovars (5×105 cells mL−1 of Salmonella Typhimurium and 3×109 cells mL−1 of Salmonella Enteritidis) onto the sensor chip was then probed with either O:4 or O:9 detection antibody, followed by O:9 or O:4 detection antibody. The first detection signals were comparable to that obtained in the multi-channel detection mode. The average value of the detection signal for Salmonella Typhimurium in the mixture when probed with O:4 detection antibody first was 66 ± 3.2 AU (Fig. 7a). The corresponding detection signal for Salmonella Enteritidis in the mixture when O:9 detection antibody was the first antibody was 60 ± 6.7 AU (Fig. 7b). The detection signal for Salmonella Typhimurium when detected in the second place (O:4 detection antibody) was 40 ±7.8 AU (Fig. 7b), and the corresponding detection signal for Salmonella Enteritidis detected secondly (O:9 detection antibody) was 28 ± 5.7 AU (Fig. 7a).

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.