title: Orientation-defined alignment and immobilization of DNA between specific surfaces.
abstract: DNA-based single-molecule studies, nanoelectronics and nanocargos require a precise placement of DNA in an orientation-defined manner. Until now, there is a lack of orientation-defined alignment and immobilization of DNA over distances smaller than several micrometers. However, this can be realized by designing bifunctionalized DNA with thiol at one end and (3-aminopropyl) tri-ethoxy silane at the other end, which specifically binds to a gold and SiO₂ layer after and during alignment, respectively. The electrode assembly consists of platinum as the electrode material for applying the AC voltage and islands of gold and silicon dioxide fabricated at a distance of about 500-800 nm by electron-beam lithography. The orientation-defined alignment and covalent binding of pUC19 DNA to specific surfaces are carried out in frequency ranges of 50 Hz-1 kHz and 100 kHz-1 MHz and observed after metallization of DNA by palladium ions by field emission scanning electron microscopy (FESEM). The bifunctionalized 890 nm long DNA was effectively aligned and immobilized between a gap of 500 to 600 nm width.
authors.affiliation: Thin Films and Nano Structures Group, Department of Physics, Bielefeld University, POB 100131, D-33501 Bielefeld, Germany.
authors.forename: A G
authors.initials: AG
authors.lastname: Venkatesh
authors.forename: Simone
authors.initials: S
authors.lastname: Herth
authors.forename: Anke
authors.initials: A
authors.lastname: Becker
authors.forename: Günter
authors.initials: G
authors.lastname: Reiss
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D004560:Electricity; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology / Q000379:methods*; D010165:Palladium / Q000737:chemistry; D010957:Plasmids / Q000737:chemistry / Q000648:ultrastructure; D010984:Platinum / Q000737:chemistry; D011437:Propylamines; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties
chemical_list: D011437:Propylamines; D012821:Silanes; D013438:Sulfhydryl Compounds; D010984:Platinum; D010165:Palladium; D006046:Gold; D012822:Silicon Dioxide; D004247:DNA; C477625:amino-propyl-triethoxysilane