title: Gate-controlled conductance switching in DNA.
abstract: Extensive evidence has shown that long-range charge transport can occur along double helical DNA, but active control (switching) of single-DNA conductance with an external field has not yet been demonstrated. Here we demonstrate conductance switching in DNA by replacing a DNA base with a redox group. By applying an electrochemical (EC) gate voltage to the molecule, we switch the redox group between the oxidized and reduced states, leading to reversible switching of the DNA conductance between two discrete levels. We further show that monitoring the individual conductance switching allows the study of redox reaction kinetics and thermodynamics at single molecular level using DNA as a probe. Our theoretical calculations suggest that the switch is due to the change in the energy level alignment of the redox states relative to the Fermi level of the electrodes.
authors.affiliation: Biodesign Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.|School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Limin
authors.initials: L
authors.lastname: Xiang
authors.affiliation: Biodesign Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.|School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, USA.|Department of Chemistry, The Pennsylvania State University, Fayette, The Eberly Campus, 2201 University Drive, Lemont Furnace, Pennsylvania 15456, USA.
authors.forename: Julio L
authors.initials: JL
authors.lastname: Palma
authors.affiliation: Biodesign Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.|School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Yueqi
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Vladimiro
authors.initials: V
authors.lastname: Mujica
authors.affiliation: Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Ratner
authors.affiliation: Biodesign Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.|School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Nongjian
authors.initials: N
authors.lastname: Tao
mesh_terms: D000880:Anthraquinones / Q000737:chemistry / Q000378:metabolism; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004553:Electric Conductivity; D055664:Electrochemical Techniques / Q000379:methods*; D008958:Models, Molecular; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D010084:Oxidation-Reduction; D013816:Thermodynamics
chemical_list: D000880:Anthraquinones; D004247:DNA