Infrared and Raman Spectroscopy and Imaging of Breast Cancer - Vibrational Spectroscopy for Tissue Analysis - page 133

0.45
0.40
0.35
0.30
0.25

Row = 77 Col = 73
1654.920

1543.049

Band shift of amide I band between
1700-1600 cm -1 .

0.20
0.15
0.10

1800 1600

Wavenumber

1400

Row = 18 Col = 75
1689.639

0.35
0.30
0.25
0.20
0.15
0.10
0.05

1546.907

e image above is obtained by a mosaic
of an area measuring 1.4 × 1.4 mm.

1800 1600 1400

Wavenumber

Figure 5.18
FTIR spectra of cancerous tissue, amide I band of cancer, and normal tissue.

group simpler. The peak centred at 1632 cm −1 is due to bonded C=O and the
band at 1538 cm −1 confirms the presence of C-N-H moieties, see Figure 5.18.
Monosubstituted amides usually exist with the -NH and C=O bonds. The
hydrogen bonded stretch is seen near 3290 cm −1 with a weaker band near
3070 cm −1 assigned to a Fermi resonance-enhanced overtone of the 1536 cm −1
band. This band at 1536 cm −1 involves both C-N stretch and C-N-H in-plane
bend in the amide II band. This band is a characteristic of monosubstituted
amides. Amide III bands absorb more weakly and are confirmed by the pres-
ence of peaks at 1310 and 1235 cm −1 . A band centred at 1160 cm −1 is due to
C-O stretching modes of the C-OH of cell proteins and the C-O group of
carbohydrates.
Spectral bands in the region of 1700 to 900 cm −1 arise from C=O, CH 2 ,
CH 3 , C-O-C, and O-P-O groups, confirming the presence of phospholip-
ids, proteins, carbohydrates, collagen, and amino acids. Differences between
normal and cancerous tissues spectra are observed. Spectra of normal and
breast cancer tissue are complex and possess well-defined and promi-
nent spectral bands at the 1700 to 700 cm −1 and 3500 to 2700 cm −1 regions.
Difference in intensity and positioning of peaks in the spectra are attributed
to the compositional changes between the normal and cancer tissues.
The intensity increase of the C-H peaks may be attributed to the increase
in the lipids, proteins, and DNA contents indicating the increment of fatty