Regensburg 2002 – scientific programme
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CPP: Chemische Physik und Polymerphysik
CPP 16: Polymere Netzwerke und Polymere mit besonderer Architektur
CPP 16.1: Talk
Thursday, March 14, 2002, 09:20–09:40, H38
Molecular structure of single DNA complexes with positively charged dendronized polymers — •Illdiko Gössl1, Lijin Shu2, A.Dieter Schlüter 2, and Juergen P. Rabe1 — 1Department of Physics, Humboldt University Berlin, Invalidenstr. 110, 10115 Berlin, Germany. — 2Institute of Chemistry, Free University Berlin, Takustr. 3, 14195 Berlin, Germany
We determined the structure of complexes of DNA and positively charged dendronized polymers. The polymers are cylindrically shaped with protonated amine groups at the periphery. Starting with the amino-terminal dendronized polystyrene of generation one, higher generations were obtained by the so called mixed "attach-toNo-dq approach (1).Thus, the synthesised dendronized polymers of generation two, three and four possessed the same polydispersity but varying number of charges as well as radii. The obtained complexes were adsorbed on bare, negatively charged mica or on mica coated with a positively charged polymer. The analysis of scanning force microscopy data indicates that DNA wraps around the dendronized polymers resulting in a DNA pitch of 2.3 nm and 2.0 nm using dendronized polymers of generation two and four, respectively. The DNA pitch varies depending on the salt concentration of the solution for complex formation. Furthermore, the complexes were negatively charged, as predicted by the theory of spontaneous overcharging of macro-ion complexes.
1. L. Shu, A. Schäfer, A. D. Schlüter, Macromolecules 33, 4321 (2000).