title: Helix-Dependent Spin Filtering through the DNA Duplex.
abstract: Recent work suggests that electrons can travel through DNA and other chiral molecules in a spin-selective manner, but little is known about the origin of this spin selectivity. Here we describe experiments on magnetized DNA-modified electrodes to explore spin-selective electron transport through hydrated duplex DNA. Our results show that the two spins migrate through duplex DNA with a different yield and that spin selectivity requires charge transport through the DNA duplex. Significantly, shifting the same duplex DNA between right-handed B- and left-handed Z-forms leads to a diode-like switch in spin selectivity; which spin moves more efficiently through the duplex depends upon the DNA helicity. With DNA, the supramolecular organization of chiral moieties, rather than the chirality of the individual monomers, determines the selectivity in spin, and thus a conformational change can switch the spin selectivity.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Zwang
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Hürlimann
authors.affiliation: Division of Chemistry, Occidental College , Los Angeles, California 90041, United States.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Hill
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Jacqueline K
authors.initials: JK
authors.lastname: Barton
mesh_terms: D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D004579:Electron Transport; D008751:Methylene Blue / Q000737:chemistry; D010078:Oxazines / Q000737:chemistry; D010084:Oxidation-Reduction; D012834:Silver / Q000737:chemistry; D018030:Silver Compounds / Q000737:chemistry
chemical_list: D010078:Oxazines; D018030:Silver Compounds; C008619:Nile Blue; D012834:Silver; D004247:DNA; C037548:silver chloride; D008751:Methylene Blue