Bending dynamics of single-walled carbon nanotubes in viscoelastic media

The mechanics and dynamics of cells and tissues are dominated by semi-flexible polymer networks, whose bending stiffness leads to nontrivial dynamics. Micron-sized beads are commonly used in microrheology approaches to measure the viscoelasticity of such systems. Insertion of such probes can lead to artefacts and is often not possibly in confined geometries in living cells. Here we introduce single-walled carbon nanotubes (SWNTs), themselves semi-flexible polymers with non-photobleaching near-infrared fluorescence, as multiscale “stealth probes” for microrheology. We investigate the bending dynamics of SWNTs embedded in viscoelastic media and analyze their thermally driven shape fluctuations. We discuss how the bending dynamics of SWNTs embedded in soft media can be used to probe the viscoelastic properties of such media.