title: Simple and label-free detection of DNA hybridization on a modified graphene nanosheets electrode.
abstract: In this study, an effective method was devised to synthesize amelogenin genes in solution and to amplify electrical detection of DNA hybridization based on graphene nanosheets (GNs) modified glassy carbon electrode (GCE). GNs are well known as effective biocompatible and conductive materials that can provide large surface area and a sufficient numbers of binding points for DNA immobilization. The biosensor fabrication processes and the electrochemical responses of probe immobilization and hybridization with target DNA were investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) using [Fe(CN)6](3-/4-) as an electrochemical redox. Due to minimum nonspecific DNA adsorption, a very high specificity of DNA hybridization was achieved, and the hybridization rate of the target DNA in optimum conditions was increased significantly. With this approach, the target DNA could be quantified in a linear range from 1.0×10(-20) to 1.0×10(-14) mol L(-1) for the first segment and from 1.0×10(-13) to 1.0×10(-6) mol L(-1) for the second segment, with a detection limit of 7.1×10(-21) mol L(-1) by 3s(b). In addition, the biosensor exhibited a high level of stability and repeatability, even for the determination of DNA sequences in real samples without amplification.
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741, Iran. Electronic address: abenvidi@yazd.ac.ir.
authors.forename: Ali
authors.initials: A
authors.lastname: Benvidi
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741, Iran.
authors.forename: Nooshin
authors.initials: N
authors.lastname: Rajabzadeh
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741, Iran.
authors.forename: Hossein Molaye
authors.initials: HM
authors.lastname: Zahedi
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Mazloum-Ardakani
authors.affiliation: Department of Biology, Faculty of Science, Yazd University, Yazd 89195-741, Iran.
authors.forename: Mohammad M
authors.initials: MM
authors.lastname: Heidari
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741, Iran.
authors.forename: Laleh
authors.initials: L
authors.lastname: Hosseinzadeh
mesh_terms: D053523:Amelogenin / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation*; D004247:DNA / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D004563:Electrochemistry; D004566:Electrodes; D005898:Glass / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D009693:Nucleic Acid Hybridization
chemical_list: D053523:Amelogenin; D006108:Graphite; D004247:DNA; D004259:DNA-Directed DNA Polymerase
keywords: Amelogenin gene; DNA biosensor; DNA hybridization; Electrochemical impedance spectroscopy; Graphene nanosheets