In this study, we investigated the biodistribution of water-soluble carbon nanotubes (CNTs) after administration through the tail vein of mice. The biodistribution was investigated using an optical and transmission electron measurement. Some of the CNTs remained in the liver and lung even 4 weeks post-injection. We also succeeded in direct observation of CNTs in the excited organs using Raman spectroscopy. In future, this method can allow to observation as a Raman mapping images of CNTs in body.
