MohammadEbrahim Minaee; Mojtaba Saadati; Mostafa Najafi; Hossein Hinari
Volume 22, Issue 5 , November and December 2015, , Pages 797-804
Abstract
Background & Objectives: Nanobiosensors could be used instead of traditional detection methods of Escherichia coli O157:H7. In this paper, a nanobiosensor for detection of rfbE gene of the Escherichia coli O157:H7 has been studied by immobilization and hybridization single strand DNA (ssDNA) sequences ...
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Background & Objectives: Nanobiosensors could be used instead of traditional detection methods of Escherichia coli O157:H7. In this paper, a nanobiosensor for detection of rfbE gene of the Escherichia coli O157:H7 has been studied by immobilization and hybridization single strand DNA (ssDNA) sequences on the electrode surface modified with gold nanoparticles.
Materials & Methods: Electrochemical impedance spectroscopy technique was used to study the properties of the sensing modified electrode. The working electrode surface was modified by electrochemical method with gold nanoparticles. The single-stranded DNA sequence using self-assembled monolayer was immobilized on the gold electrode for two hours. A mixed monolayer comprising both mercaptohexanol (MCH) and mercaptopropionic acid (MPA) were used as blocking layer. The hybridization DNA/DNA was performed by immersion of the modified gold electrode into ssDNA at a concentration of 1 μM target DNA.
Results: The results showed that the electrode modified with gold nanoparticles after immobilizing ssDNA effectively detected rfbE gene of Escherichia coli O157:H7 by DNA hybridization . The nanobiosiosensor showed suitable selectivity for the detection of target DNA complementary sequence compared with the mismatched oligonucleotides sequence and the noncomplementary oligonucleotides sequence.
Conclusion: According to the results obtained and similar studies, the electrochemical nanobiosensor based on DNA hybridization has advantages such as low cost, simplicity, and miniaturization and can provide a basis for the development of genomic detection tools.