title: Light-induced in situ patterning of DNA-tagged biomolecules and nanoparticles.
abstract: We present an in situ method for the selective manipulation of DNA-tagged nano-objects such as vesicles or gold colloids in aqueous solution, at neutral pH. The method makes use of the photosensitizer concept found in photodynamic therapy. Here, single-stranded DNA is immobilized onto a surface via the biotin/streptavidin linkage. If the streptavidin is fluorescently labeled, reactive species will be created during laser-induced photobleaching of the label. These reactive species can then completely or partly suppress the DNA hybridization and cause the removal of the streptavidin. The technique thereby enables a dynamic on-off control over surface density of immobilized DNA-tagged nano-objects. Furthermore, combining this in situ manipulation of DNA with prepatterning of single-stranded DNA in the micro and later in the nano range provides a means for the dynamic patterning required for applications in biosensing and nanotechnology.
authors.affiliation: Dynamic BioInterfaces Group, Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland. brigitte.staedler@mat.ethz.ch
authors.forename: Brigitte M
authors.initials: BM
authors.lastname: Städler
authors.forename: Christoph B
authors.initials: CB
authors.lastname: Huwiler
authors.forename: Janos
authors.initials: J
authors.lastname: Vörös
authors.forename: H Michelle
authors.initials: HM
authors.lastname: Grandin
mesh_terms: D000327:Adsorption; D001704:Biopolymers / Q000737:chemistry* / Q000528:radiation effects; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000528:radiation effects; D003460:Crystallization / Q000379:methods*; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D008422:Materials Testing; D008846:Micromanipulation / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects; D013499:Surface Properties
chemical_list: D001704:Biopolymers; D020099:Coated Materials, Biocompatible; D004247:DNA