Optical coherence tomography picorheology of biopolymer solutions

Abstract

We describe an interferometric optical fiber based dynamic light scattering technique to study the linear viscoelasticity of complex fluids. This digital correlator based method enables viscoelasticity to be probed at high frequencies (10-2 - 105 Hz) over picoliter regions of an aqueous sample. We demonstrate the technique using solutions of the self-assembled biological polymers aggrecan and fibrin. The technique is demonstrated in an optical coherence tomography type mode of action with picorheology measurements at 40 μm transverse sections (490 pl volumes) over a 1 cm sample length. The method allowed the viscoelasticity of aggrecan to be probed and provided a direct measurement of the persistence length of the fibrin fibers (Lp =32±2 cm). © 2008 American Institute of Physics.