HNYLUCHOVÁ Zuzana Brno University of Technology

DLS Microrheology of Biopolymer Solution, Probe Size Effect

Co-authors MONDEK Jakub, PEKAŘ Miloslav

Structure of biopolymers plays important role for its industrial applications and affect their potential usability. The more information about the micro and macrostructure of the sample the better is evaluation of potential behavior of the sample and suitability for use. For microstructure determination we used passive microrheology method by utilizing diffusing light spectroscopy device and microrheology probes to characterize properties of the sample. Three different probes with unlike particle surfaces were chosen to determine the most appropriate one for biopolymer solutions measurements. To estimate possible probe – biopolymer interactions, which are undesirable for microrheological measurements, zeta potential of particles in the solutions was studied. Results from DLS microrheology were compared with FCS “nanorheology” measurements. Our data show importance of appropriate particle choice, with an emphasis on the particle surface chemistry. The most suitable particles for biopolymer solutions are polystyrene particles, or PS-COOH particles that avoid particle – biopolymer interaction. DLS and FCS microrheology data exhibit good agreement in wide time range.