Raman Imaging and Raman Mapping - Emerging Raman Applications and Techniques in Biomedical and Pharmaceutical Fields - page 105

Fig. 5.5. SERS image of mouse liver. a Whole-body map (1-mm steps) of nude
mouse 2 h after tail vein injection of SERS nanoparticles. Most SERS particles ac-
cumulate in the liver (L, arrow ). b Higher resolution (750 μm steps) and higher defi-
nition map of liver ( arrow ) showing organ detail including differentiation of the two
liver lobes (reprinted with permission from [33]. Copyright 2008 National Academy
of Sciences, USA)
This SERS labeling approach has been used by Yu and co-workers for
imaging apoptosis in cells and lung cancer tissue [32]. In most reported SERS
imaging papers, the SERS nanoparticles have been prepared by the investi-
gators themselves. Yu et al. were able to employ the commercially available
SERS-active nanoparticles, and so have demonstrated that SERS imaging is
now open to a much larger community of scientists than just SERS specialists.
A similar methodology has been extended by Keren et al. to non-invasive
imaging of the mouse, using SERS nanoparticles that had accumulated in the
liver [33]. An example is shown in Fig. 5.5. This group also demonstrated
that single-walled carbon nanotubes, which have an intense Raman band at
1 , 593 cm − 1 , can be functionalized and used for non-invasive imaging.
5.3.4 Correlative Raman Spectroscopy and Optical Coherence
Tomographic (OCT) Imaging
Several groups have used Raman spectroscopy in combination with OCT,
which is a rapid, high spatial resolution technique. OCT is used to identify
suspicious areas of tissue and single-point Raman spectroscopy is used to
confirm presence or absence of disease. Application to dental caries is discussed
in Chap. 15. A very recent development is an integrated Raman/OCT probe
[34], which is shown in Fig. 5.6. Using biopsied breast tissue, the instrument