Investigation of the thin film crystallization of a DNA copolymer hybrid composed of chitosan.
Résumé
The authors describe for the first time the crystn. in thin films of a DNA copolymer composed of a low mol. wt. chitosan backbone to which a sequence of nucleic acids is grafted (chitosan-g-ssDNA). As assessed by at. force microscopy, optical microscopy and spectroscopy, crystn. occurs due to intermol. H bonding in which the nucleic acid strands engage. The morphol. of the crystals depends on the affinity for the surface of the polymer segments that compose the DNA copolymer hybrid. The nucleic acids adsorb on mica and SiO2 on which side-branched structures are obsd. whereas chitosan interacts preferentially with Au, and dendritic crystals are assembled. Attenuated total reflectance IR spectroscopy supports the high ordering of the structure and the establishment of strong intermol. interactions by H bonding.