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Label-free as-grown double wall carbon nanotubes bundles for Salmonella typhimurium immunoassay.

Punbusayakul N, Talapatra S, Ajayan PM, Surareungchai W - Chem Cent J (2013)

Bottom Line: Ag/AgCl) and the optimum impregnated anti-Salmonella of 10 μg/mL to detect S. typhimurium cells (0-10(9) CFU/mL).The DW immunosensor exhibited a detection range of 10(2) to 10(7) CFU/mL for the bacteria with a limit of detection of 8.9 CFU/mL according to the IUPAC recommendation.These findings suggest that the use of a label-free DW immunosensor is promising for detecting S. typhimurium.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Agro-Industry, Mae Fah Luang University, Chiang Rai 57100, Thailand.

ABSTRACT

Background: A label-free immunosensor from as-grown double wall carbon nanotubes (DW) bundles was developed for detecting Salmonella typhimurium. The immunosensor was fabricated by using the as-grown DW bundles as an electrode material with an anti-Salmonella impregnated on the surface. The immunosensor was electrochemically characterized by cyclic voltammetry. The working potential (100, 200, 300 and 400 mV vs. Ag/AgCl) and the anti-Salmonella concentration (10, 25, 50, 75, and 100 μg/mL) at the electrode were subsequently optimized. Then, chronoamperometry was used with the optimum potential of 100 mV vs. Ag/AgCl) and the optimum impregnated anti-Salmonella of 10 μg/mL to detect S. typhimurium cells (0-10(9) CFU/mL).

Results: The DW immunosensor exhibited a detection range of 10(2) to 10(7) CFU/mL for the bacteria with a limit of detection of 8.9 CFU/mL according to the IUPAC recommendation. The electrode also showed specificity to S. typhimurium but no current response to Escherichia coli.

Conclusions: These findings suggest that the use of a label-free DW immunosensor is promising for detecting S. typhimurium.

No MeSH data available.


Related in: MedlinePlus

Chronoamperograms at (blue) the bare DW electrode, (green) the DW electrode with MAb at the concentration of 10 μg/mL, and (red) the MAb-DW electrode with cells (109 CFU/mL) at the working potential of 100 V vs. Ag/AgCl in citrate phosphate buffer (0.05 M, pH 5.5) solution.
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Figure 4: Chronoamperograms at (blue) the bare DW electrode, (green) the DW electrode with MAb at the concentration of 10 μg/mL, and (red) the MAb-DW electrode with cells (109 CFU/mL) at the working potential of 100 V vs. Ag/AgCl in citrate phosphate buffer (0.05 M, pH 5.5) solution.

Mentions: The MAb at the concentration of 10 μg/mL and the working potential of 100 mV vs. Ag/AgCl was used for Salmonella typhimurium detection. It was found that there was no signal of the cells obtained when only the blocking agent was immobilized onto the electrode surface, while the signal of the cells was obviously observed at the MAb-DW electrode (Figure 4). This confirms that the electrode is not able to detect any cells when MAb is not immobilized onto the electrode surface.


Label-free as-grown double wall carbon nanotubes bundles for Salmonella typhimurium immunoassay.

Punbusayakul N, Talapatra S, Ajayan PM, Surareungchai W - Chem Cent J (2013)

Chronoamperograms at (blue) the bare DW electrode, (green) the DW electrode with MAb at the concentration of 10 μg/mL, and (red) the MAb-DW electrode with cells (109 CFU/mL) at the working potential of 100 V vs. Ag/AgCl in citrate phosphate buffer (0.05 M, pH 5.5) solution.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3716848&req=5

Figure 4: Chronoamperograms at (blue) the bare DW electrode, (green) the DW electrode with MAb at the concentration of 10 μg/mL, and (red) the MAb-DW electrode with cells (109 CFU/mL) at the working potential of 100 V vs. Ag/AgCl in citrate phosphate buffer (0.05 M, pH 5.5) solution.
Mentions: The MAb at the concentration of 10 μg/mL and the working potential of 100 mV vs. Ag/AgCl was used for Salmonella typhimurium detection. It was found that there was no signal of the cells obtained when only the blocking agent was immobilized onto the electrode surface, while the signal of the cells was obviously observed at the MAb-DW electrode (Figure 4). This confirms that the electrode is not able to detect any cells when MAb is not immobilized onto the electrode surface.

Bottom Line: Ag/AgCl) and the optimum impregnated anti-Salmonella of 10 μg/mL to detect S. typhimurium cells (0-10(9) CFU/mL).The DW immunosensor exhibited a detection range of 10(2) to 10(7) CFU/mL for the bacteria with a limit of detection of 8.9 CFU/mL according to the IUPAC recommendation.These findings suggest that the use of a label-free DW immunosensor is promising for detecting S. typhimurium.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Agro-Industry, Mae Fah Luang University, Chiang Rai 57100, Thailand.

ABSTRACT

Background: A label-free immunosensor from as-grown double wall carbon nanotubes (DW) bundles was developed for detecting Salmonella typhimurium. The immunosensor was fabricated by using the as-grown DW bundles as an electrode material with an anti-Salmonella impregnated on the surface. The immunosensor was electrochemically characterized by cyclic voltammetry. The working potential (100, 200, 300 and 400 mV vs. Ag/AgCl) and the anti-Salmonella concentration (10, 25, 50, 75, and 100 μg/mL) at the electrode were subsequently optimized. Then, chronoamperometry was used with the optimum potential of 100 mV vs. Ag/AgCl) and the optimum impregnated anti-Salmonella of 10 μg/mL to detect S. typhimurium cells (0-10(9) CFU/mL).

Results: The DW immunosensor exhibited a detection range of 10(2) to 10(7) CFU/mL for the bacteria with a limit of detection of 8.9 CFU/mL according to the IUPAC recommendation. The electrode also showed specificity to S. typhimurium but no current response to Escherichia coli.

Conclusions: These findings suggest that the use of a label-free DW immunosensor is promising for detecting S. typhimurium.

No MeSH data available.


Related in: MedlinePlus