title: Electrical manipulation of oligonucleotides grafted to charged surfaces.
abstract: The electrical manipulation of short DNA molecules on surfaces offers novel functionalities with fascinating possibilities in the field of bio-interfaces. Here we present systematic investigations of the electrical interactions which govern the structure of oligonucleotides on charged gold surfaces. Successively, we address influences of the applied field strength, the role of DC electrode potentials, in particular for polycrystalline surfaces, as well as screening effects of the surrounding electrolyte solution. Data obtained for single and double stranded DNA exhibit differences which can be attributed to the dissimilar flexibility of the different molecular conformations. A comparison of the experimental results with a basic model shows how the alignment of the molecules adjusts according to a balance between electrically induced ordering and stochastic thermal motions. The presented conclusions are expected to be of general relevance for the behaviour of polyelectrolytes exposed to localized electric fields at interfaces.
authors.affiliation: Walter Schottky Institute, Technical University Munich, Am Coulombwall 3, 85748, Garching, Germany. rant@wsi.tum.de
authors.forename: Ulrich
authors.initials: U
authors.lastname: Rant
authors.forename: Kenji
authors.initials: K
authors.lastname: Arinaga
authors.forename: Shozo
authors.initials: S
authors.lastname: Fujita
authors.forename: Naoki
authors.initials: N
authors.lastname: Yokoyama
authors.forename: Gerhard
authors.initials: G
authors.lastname: Abstreiter
authors.forename: Marc
authors.initials: M
authors.lastname: Tornow
mesh_terms: D004247:DNA / Q000737:chemistry; D004563:Electrochemistry; D004573:Electrolytes / Q000737:chemistry; D005453:Fluorescence; D009841:Oligonucleotides / Q000737:chemistry*; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D004573:Electrolytes; D009841:Oligonucleotides; D004247:DNA