title: A nanocarbon film electrode as a platform for exploring DNA methylation.
abstract: We describe the quantitative nonlabel electrochemical detection of both cytosine (C) and methylcytosine (mC) in oligonucleotides using newly developed nanocarbon film electrodes. The film consists of nanocrystalline sp2 and sp3 mixed bonds formed by employing the electron cyclotron resonance (ECR) sputtering method. We successfully used this film to develop a simple electrochemical DNA methylation analysis technique based on the measurement of the differences between the oxidation currents of C and mC since our ECR nanocarbon film electrode can directly measure all DNA bases more quantitatively than conventional glassy carbon or boron-doped diamond electrodes. The excellent properties of ECR nanocarbon film electrodes result from the fact that they have a wide potential window while maintaining the high electrode activity needed to oxidize oligonucleotides electrochemically. Proof-of-concept experiments were performed with synthetic oligonucleotides including different numbers of C and mC. This film allowed us to perform both C- and mC-positive assays solely by using the electrochemical oxidation of oligonucleotides without bisulfite or labeling processes.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
authors.forename: Dai
authors.initials: D
authors.lastname: Kato
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Sekioka
authors.forename: Akio
authors.initials: A
authors.lastname: Ueda
authors.forename: Ryoji
authors.initials: R
authors.lastname: Kurita
authors.forename: Shigeru
authors.initials: S
authors.lastname: Hirono
authors.forename: Koji
authors.initials: K
authors.lastname: Suzuki
authors.forename: Osamu
authors.initials: O
authors.lastname: Niwa
mesh_terms: D002244:Carbon / Q000737:chemistry*; D017357:Cyclotrons / Q000295:instrumentation; D004247:DNA / Q000737:chemistry*; D019175:DNA Methylation; D004563:Electrochemistry; D004566:Electrodes; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties
chemical_list: D008567:Membranes, Artificial; D002244:Carbon; D004247:DNA