FTIR and Raman Characteristic Peak Frequencies in Biological Studies - Vibrational Spectroscopy for Tissue Analysis - page 287

Characteristic Peak Frequencies
It is believed that accurate peak definitions can have a great influence on reli-
ability of the results provided through different spectroscopic techniques.
As a result, and with the aim of putting this shortcoming aside, a wide range
of the most frequently seen peaks are tabulated in this chapter. This will
enhance understanding of the major peak assignments to specific functional
groups that are present in complex biological molecules. For example, peaks
in the area of 900 cm −1 are attributed to phosphodiester groups in both Raman
and FTIR studies. The same finding can be seen in the area of 990-940 cm −1
(peaks related to C-C and C-O). More important peaks, such as those on
the area of 1060-1030 cm −1 (C-C and C-O, mainly due to proteins and car-
bohydrates), 2000-1080 cm −1 (C-C, C-O, and phosphate of nucleic acids and
membrane phospholipids, and partially proteins), 1350-1200 cm −1 (amide III
region), 1600-1480 cm −1 (amide II region), 1800-1600 cm −1 (amide I region),
and 3100-2800 cm −1 (CH region) also show considerable similarities in both
techniques.
Summary
This chapter attempts to illustrate the significant attention being given
to spectroscopy as a newly emerging method for biological studies,
particularly cancer detection. In addition, it leads to the conclusion that a
considerable amount of information can be obtained from spectroscopic
methods. It also proves the similarities, which can be seen in peak defini-
tions in both FTIR and Raman spectroscopy techniques. In other words,
regardless of the method used, the peak intensities could be defined
s i m i l a rly.
This chapter can be used as a unique and reliable database of peak defini-
tions for both Raman and FTIR studies, and it can surely provide significant
assistance to those who concentrate on these methods. However, it should
be mentioned that this is an ongoing project. Newly conducted researches
along with their introduced peak frequencies will gradually be used in order
to make this table more comprehensive.
Because the IR and Raman spectroscopic techniques are complementary,
similarities of peaks attributed to functional groups are also observed in
biological molecules. In closing, this chapter can be used as a unique and
reliable database of peak definitions for IR and Raman studies of biological
molecules, specifically cancer studies.