title: Studies on the structure of coumarin-modified dextran nanoparticles by fluorescence spectroscopy.
abstract: The photophysical and photochemical characteristics of nano-scaled particles obtained via solvent displacement from coumarin-modified dextrans were studied by means of absorption- and fluorescence-spectroscopy. The environment-dependent fluorescence emission of the pendant 4-methyl-7-alkoxy coumarin groups was exploited as a probe to gain information about the inner structure of the polysaccharide based nanoparticles. Time-resolved fluorescence measurements showed that the particles had two domains of different polarity and it could be confirmed that the core of the nano-assemblies contained water. Moreover, preliminary experiments were carried out demonstrating the possibility to control the morphology of the nanoparticles by the light induced 2π+2π cycloaddition of the coumarin substituents.
authors.affiliation: Laboratory of Fibre and Cellulose Technology, Åbo Akademi University, Porthansgatan 3, 20500 Åbo, Finland.
authors.forename: Holger
authors.initials: H
authors.lastname: Wondraczek
authors.forename: Anne
authors.initials: A
authors.lastname: Kotiaho
authors.forename: Marja
authors.initials: M
authors.lastname: Niemi
authors.forename: Pedro
authors.initials: P
authors.lastname: Fardim
authors.forename: Thomas
authors.initials: T
authors.lastname: Heinze
mesh_terms: D003374:Coumarins / Q000737:chemistry*; D061565:Cycloaddition Reaction; D003911:Dextrans / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D003374:Coumarins; D003911:Dextrans; C030123:coumarin