title: Synthesis and self-assembly of a DNA molecular brush.
abstract: We report herein on the polymer-crystallization-assisted thiol-ene photosynthesis of an amphiphilic comb/graft DNA copolymer, or molecular brush, composed of a hydrophobic poly(2-oxazoline) backbone and hydrophilic short single-stranded nucleic acid grafts. Coupling efficiencies are above 60% and thus higher as compared with the straight solid-phase-supported synthesis of amphiphilic DNA block copolymers. The DNA molecular brushes self-assemble into sub-micron-sized spherical structures in water as evidenced by light scattering as well as atomic force and electron microscopy imaging. The nucleotide sequences remain functional, as assessed by UV and fluorescence spectroscopy subsequent to isoindol synthesis at the surface of the structures. The determination of a vesicular morphology is supported by encapsulation and subsequent spectroscopy monitoring of the release of a water-soluble dye and spectroscopic quantification of the hybridization efficiency (30% in average) of the functional nucleic acid strands engaged in structure formation: about one-half of the nucleotide sequences are available for hybridization, whereas the other half are hindered within the self-assembled structure. Because speciation between complementary and non complementary sequences in the medium could be ascertained by confocal laser scanning microscopy, the stable self-assembled molecular brushes demonstrate the potential for sensing applications.
authors.affiliation: Department of Inorganic and Analytical Chemistry and ‡Department of Physical Chemistry, University of Geneva , Quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland.
authors.forename: Dawid
authors.initials: D
authors.lastname: Kedracki
authors.forename: Mahshid
authors.initials: M
authors.lastname: Chekini
authors.forename: Plinio
authors.initials: P
authors.lastname: Maroni
authors.forename: Helmut
authors.initials: H
authors.lastname: Schlaad
authors.forename: Corinne
authors.initials: C
authors.lastname: Nardin
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D004247:DNA / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D010080:Oxazoles / Q000737:chemistry*
chemical_list: D010080:Oxazoles; C577913:poly(2-oxazoline); D004247:DNA