title: Direct detection and discrimination of double-stranded oligonucleotide corresponding to hepatitis C virus genotype 3a using an electrochemical DNA biosensor based on peptide nucleic acid and double-stranded DNA hybridization.
abstract: Development of an electrochemical DNA biosensor for the direct detection and discrimination of double-stranded oligonucleotide (dsDNA) corresponding to hepatitis C virus genotype 3a, without its denaturation, using a gold electrode is described. The electrochemical DNA sensor relies on the modification of the gold electrode with 6-mercapto-1-hexanol and a self-assembled monolayer of 14-mer peptide nucleic acid probe, related to the hepatitis C virus genotype 3a core/E1 region. The increase of differential pulse voltammetric responses of methylene blue, upon hybridization of the self-assembled probe with the target ds-DNA to form a triplex is the principle behind the detection and discrimination. Some hybridization experiments with non-complementary oligonucleotides were carried out to assess whether the developed DNA sensor responds selectively to the ds-DNA target. Diagnostic performance of the biosensor is described and the detection limit was found to be 1.8 x 10(-12) M in phosphate buffer solution, pH 7.0. The relative standard deviation of measurements of 100 pM of target ds-DNA performed with three independent probe-modified electrodes was 3.1%, indicating a remarkable reproducibility of the detection method.
authors.affiliation: Electroanalytical Chemistry Laboratory, Faculty of Chemistry, University of Tabriz, Bd. 29 Bahman, 51666-14776 Tabriz, Iran. pournaghiazar@tabrizu.ac.ir
authors.forename: M H
authors.initials: MH
authors.lastname: Pournaghi-Azar
authors.forename: F
authors.initials: F
authors.lastname: Ahour
authors.forename: M S
authors.initials: MS
authors.lastname: Hejazi
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D004566:Electrodes; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D057230:Limit of Detection; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry / Q000235:genetics*; D020135:Peptide Nucleic Acids / Q000032:analysis / Q000235:genetics*
chemical_list: D004279:DNA, Viral; D009841:Oligonucleotides; D020135:Peptide Nucleic Acids