Carbon nanotube-based aptasensor for sensitive electrochemical detection of whole-cell Salmonella

Hasan, Md Rakibul and Pulingam, Thiruchelvi and Appaturi, Jimmy Nelson and Zifruddin, Anis Nadyra and Teh, Swe Jyan and Lim, Teck Wei and Ibrahim, Fatimah and Leo, Bey Fen and Thong, Kwai Lin (2018) Carbon nanotube-based aptasensor for sensitive electrochemical detection of whole-cell Salmonella. Analytical Biochemistry, 554. pp. 34-43. ISSN 0003-2697

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Official URL: https://doi.org/10.1016/j.ab.2018.06.001

Abstract

In this study, an amino-modified aptasensor using multi-walled carbon nanotubes (MWCNTs)-deposited ITO electrode was prepared and evaluated for the detection of pathogenic Salmonella bacteria. An amino-modified aptamer (ssDNA) which binds selectively to whole-cell Salmonella was immobilised on the COOH-rich MWCNTs to produce the ssDNA/MWCNT/ITO electrode. The morphology of the MWCNT before and after interaction with the aptamers were observed using scanning electron microscopy (SEM). Cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to investigate the electrochemical properties and conductivity of the aptasensor. The results showed that the impedance measured at the ssDNA/MWCNT/ITO electrode surface increased after exposure to Salmonella cells, which indicated successful binding of Salmonella on the aptamer-functionalised surface. The developed ssDNA/MWCNT/ITO aptasensor was stable and maintained linearity when the scan rate was increased from 10 mV s−1 to 90 mV s−1. The detection limit of the ssDNA/MWCNT/ITO aptasensor, determined from the sensitivity analysis, was found to be 5.5 × 101 cfu mL−1 and 6.7 × 101 cfu mL−1 for S. Enteritidis and S. Typhimurium, respectively. The specificity test demonstrated that Salmonella bound specifically to the ssDNA/MWCNT/ITO aptasensor surface, when compared with non-Salmonella spp. The prepared aptasensor was successfully applied for the detection of Salmonella in food samples.

Item Type: Article
Uncontrolled Keywords: Aptasensor; Cyclic voltammetry; Electrochemical impedance spectroscopy; Multi-walled carbon nanotubes; Scanning electron microscopy
Subjects: Q Science > Q Science (General)
Q Science > QH Natural history
R Medicine
Divisions: Faculty of Engineering
Faculty of Medicine
Faculty of Science > Institute of Biological Sciences
Deputy Vice Chancellor (Research & Innovation) Office > Nanotechnology & Catalysis Research Centre
Depositing User: Ms. Juhaida Abd Rahim
Date Deposited: 19 Aug 2019 01:09
Last Modified: 19 Aug 2019 01:09
URI: http://eprints.um.edu.my/id/eprint/21940

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