title: Chemically-modified graphenes for oxidation of DNA bases: analytical parameters.
abstract: We studied the electroanalytical performances of chemically-modified graphenes (CMGs) containing different defect densities and amounts of oxygen-containing groups, namely graphite oxide (GPO), graphene oxide (GO), thermally reduced graphene oxide (TR-GO) and electrochemically reduced graphene oxide (ER-GO) by comparing the sensitivity, selectivity, linearity and repeatability towards the oxidation of DNA bases. We have observed that for differential pulse voltammetric (DPV) detection of adenine and cytosine, all CMGs showed enhanced sensitivity to oxidation, while for guanine and thymine, ER-GO and TR-GO exhibited much improved sensitivity over bare glassy carbon (GC) as well as over GPO and GO. There is also significant selectivity enhancement when using GPO for adenine and TR-GO for thymine. Our results have uncovered that the differences in surface functionalities, structure and defects of various CMGs largely influence their electrochemical behaviour in detecting the oxidation of DNA bases. The findings in this report will provide a useful guide for the future development of label-free electrochemical devices for DNA analysis.
authors.affiliation: Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.
authors.forename: Madeline Shuhua
authors.initials: MS
authors.lastname: Goh
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bonanni
authors.forename: Adriano
authors.initials: A
authors.lastname: Ambrosi
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Sofer
authors.forename: Martin
authors.initials: M
authors.lastname: Pumera
mesh_terms: D000225:Adenine / Q000737:chemistry; D003596:Cytosine / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D006147:Guanine / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D013941:Thymine / Q000737:chemistry
chemical_list: D006147:Guanine; D006108:Graphite; D003596:Cytosine; D004247:DNA; D000225:Adenine; D013941:Thymine; D010100:Oxygen