title: Graphene electrode modified with electrochemically reduced graphene oxide for label-free DNA detection.
abstract: A novel printed graphene electrode modified with electrochemically reduced graphene oxide was developed for the detection of a specific oligonucleotide sequence. The graphene oxide was immobilized onto the surface of a graphene electrode via π-π bonds and electrochemical reduction of graphene oxide was achieved by cyclic voltammetry. A much higher redox current was observed from the reduced graphene oxide-graphene double-layer electrode, a 42% and 36.7% increase, respectively, in comparison with that of a bare printed graphene or reduced graphene oxide electrode. The good electron transfer activity is attributed to a combination of the large number of electroactive sites in reduced graphene oxide and the high conductivity nature of graphene. The probe ssDNA was further immobilized onto the surface of the reduced graphene oxide-graphene double-layer electrode via π-π bonds and then hybridized with its target cDNA. The change of peak current due to the hybridized dsDNA could be used for quantitative sensing of DNA concentration. It has been demonstrated that a linear range from 10(-7)M to 10(-12)M is achievable for the detection of human immunodeficiency virus 1 gene with a detection limit of 1.58 × 10(-13)M as determined by three times standard deviation of zero DNA concentration.
authors.affiliation: Wolfson Nanomaterials & Devices Laboratory, Faculty of Science and Engineering, University of Plymouth, Devon PL4 8AA, UK; School of Biomedical and Healthcare Sciences, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth University, Devon, PL4 8AA, UK. Electronic address: bing.li@plymouth.ac.uk.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: Wolfson Nanomaterials & Devices Laboratory, Faculty of Science and Engineering, University of Plymouth, Devon PL4 8AA, UK; School of Biomedical and Healthcare Sciences, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth University, Devon, PL4 8AA, UK.
authors.forename: Genhua
authors.initials: G
authors.lastname: Pan
authors.affiliation: School of Biomedical and Healthcare Sciences, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth University, Devon, PL4 8AA, UK.
authors.forename: Neil D
authors.initials: ND
authors.lastname: Avent
authors.affiliation: School of Geography, Earth and Environmental Sciences, Faculty of Science and Egineering, University of Plymouth, Devon PL4 8AA, UK.
authors.forename: Roy B
authors.initials: RB
authors.lastname: Lowry
authors.affiliation: School of Biomedical and Healthcare Sciences, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth University, Devon, PL4 8AA, UK.
authors.forename: Tracey E
authors.initials: TE
authors.lastname: Madgett
authors.affiliation: School of Biomedical and Healthcare Sciences, Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth University, Devon, PL4 8AA, UK.
authors.forename: Paul L
authors.initials: PL
authors.lastname: Waines
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D004247:DNA / Q000032:analysis*; D015342:DNA Probes / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D005814:Genes, Viral; D006108:Graphite / Q000737:chemistry*; D015658:HIV Infections / Q000821:virology; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D061925:Immobilized Nucleic Acids / Q000737:chemistry; D057230:Limit of Detection; D009693:Nucleic Acid Hybridization; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*
chemical_list: D015342:DNA Probes; D004277:DNA, Single-Stranded; D061925:Immobilized Nucleic Acids; D010087:Oxides; D006108:Graphite; D004247:DNA
keywords: Electrochemical sensor; Electrochemically reduced graphene oxide; Grapheme; Label-free DNA detection