title: Functionalization of single-walled carbon nanotubes for direct and selective electrochemical detection of DNA.
abstract: We report here a new strategy to graft both redox and DNA probes on carbon nanotubes to make a label-free DNA sensor. Oxidized single-walled carbon nanotubes are first immobilized on a self-assembled monolayer of cysteamine; then the redox probe, a quinone derivative 3-[(2-aminoethyl)sulfanyl-5-hydroxy-1,4-naphthoquinone], is grafted on the free carboxylic groups of the nanotubes. After that, for DNA probe grafting, new carboxylic sites are generated via an aryl diazonium route. After hybridization with a complementary sequence, the conformational changes of DNA could influence the redox kinetics of quinone, leading to a current increase of the redox signal, detected by square wave voltammetry. The system is selective, as it can discriminate a single mismatched sequence from the complementary one.
authors.affiliation: Laboratoire Interfaces-Traitements-Organisation et Dynamique des Systèmes (ITODYS), associé au CNRS-UMR 7086, Université Paris Diderot-Paris 7, 15 rue Jean-Antoine de Baïf, 75205, PARIS cedex 13, France.
authors.forename: Qi Dong
authors.initials: QD
authors.lastname: Zhang
authors.forename: Benoît
authors.initials: B
authors.lastname: Piro
authors.forename: Vincent
authors.initials: V
authors.lastname: Noël
authors.forename: Steeve
authors.initials: S
authors.lastname: Reisberg
authors.forename: Minh-Chau
authors.initials: MC
authors.lastname: Pham
mesh_terms: D003543:Cysteamine / Q000737:chemistry; D004247:DNA / Q000032:analysis*; D015342:DNA Probes / Q000032:analysis / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D010084:Oxidation-Reduction; D011809:Quinones / Q000737:chemistry
chemical_list: D015342:DNA Probes; D037742:Nanotubes, Carbon; D011809:Quinones; D003543:Cysteamine; D006046:Gold; D004247:DNA