  Vibrational energy transfer from photo-excited single-wall carbon nanotubes
(SWCNTs) to coupled proteins is a key to engineer thermally induced biological
reactions such as photothermal therapy. Here, we explored vibrational energy
transfer from the photo-excited SWCNTs to different adsorbed biological
materials by means of a femtosecond pump-probe technique. We show that the
vibrational relaxation time of the radial breathing modes (RBMs) in SWCNTs
significantly depends on the structure of coupled materials, i.e. proteins or
biopolymers, indicating the vibrational energy transfer is governed by overlap
of phonon density of states between the SWCNTs and coupled materials.
