Fig. 5From: A brief review of non-invasive brain imaging technologies and the near-infrared optical bioimagingCommonly used materials for fluorescence imaging. Diagrams of the spectral ranges of the major fluorescence materials and its tissue penetration capacity. SWNTs, single walled carbon nanotubes; RENPs, rare-earth doped nanoparticles; D-A-D, donor-acceptor-donorBack to article page