title: Application of graphene-pyrenebutyric acid nanocomposite as probe oligonucleotide immobilization platform in a DNA biosensor.
abstract: A stable and uniform organic-inorganic nanocomposite that consists of graphene (GR) and pyrenebutyric acid (PBA) was obtained by ultrasonication, which was characterized by scanning electron microscopy (SEM) and UV-vis absorption spectra. The dispersion was dropped onto a gold electrode surface to obtain GR-PBA modified electrode (GR-PBA/Au). Electrochemical behaviors of the modified electrode were characterized by cyclic voltammetry and electrochemical impedance spectroscopy using [Fe(CN)6](3-/4-) as the electroactive probe. A novel DNA biosensor was constructed based on the covalent coupling of amino modified oligonucleotides with the carboxylic group on PBA. By using methylene blue (MB) as a redox-active hybridization indicator, the biosensor was applied to electrochemically detect the complementary sequence, and the results suggested that the peak currents of MB showed a good linear relationship with the logarithm values of target DNA concentrations in the range from 1.0×10(-15) to 5.0×10(-12) M with a detection limit of 3.8×10(-16) M. The selectivity experiment also showed that the biosensor can well distinguish the target DNA from the non-complementary sequences.
authors.affiliation: Department of Chemistry and Environment Science, Fujian Province University Key Laboratory of Analytical Science, Zhangzhou Normal University, Zhangzhou 363000, PR China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.forename: Xili
authors.initials: X
authors.lastname: Cai
authors.forename: Meixia
authors.initials: M
authors.lastname: Zheng
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.forename: Shulian
authors.initials: S
authors.lastname: Jiang
authors.forename: Qingxiang
authors.initials: Q
authors.lastname: Wang
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis*; D015342:DNA Probes / Q000378:metabolism*; D058266:Dielectric Spectroscopy; D004563:Electrochemistry; D006108:Graphite / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry*; D009841:Oligonucleotides / Q000378:metabolism*; D011721:Pyrenes / Q000737:chemistry*; D015203:Reproducibility of Results; D013535:Suspensions; D013997:Time Factors
chemical_list: D015342:DNA Probes; D009841:Oligonucleotides; D011721:Pyrenes; D013535:Suspensions; C002218:1-pyrenebutyrate; D006108:Graphite; D004247:DNA; D008751:Methylene Blue
keywords: DNA biosensor; Graphene; Methylene blue; Pyrenebutyric acid