C. Liu et al./Journal of Luminescence 119-120(2006)132-136 0.8 7 1464cm 4 0.3 0.2 g04 5010001050110011501200 14001450150015501600165017001750 Fig. 2. IR absorption spectra in the amide I and amide Il egions. Curves I. Il and Ill are corresponding to the 0x104 absorption of normal. benign and malignant tissues, respec- 2.0x10-4 83.0x10 and benign tissues. Then, the absorption peak at 84.0x10-4 1500 cm can be observed only in malignant tissue and might result from the C=C vibration 60x10 of 106010801100 1474 cm, whose double peak structure was not Wavenumber(cm") reported before, emerge as shown in Fig. 2 Fig. 1. IR absorption spectra in the drate absorption The IR spectra in the lipid and N-H amino region(a)and their second-order de b). Curves l. ll group absorption regio from 2700 to 3600 cm and Ill represent absorption of norma and malignant are shown in Fig. 3(a). The three main peaks at tissues, respectively 2850.2917 and 2955cm-I are all resulted from the stretching vibrations of the organic groups CH and CH3 of the acyl chains inside fatty acids [9] the spectrum of malignant cancerous tissue is more The calculated second order derivatives are shown complicated. There are two obvious characters in Fig. 3(b). It is easy to see that the IR absorption shown in spectrum of diseased tissues. One is the spectral structures, hence the chemical compo- absorption peaks shift somewhat relative to that of nents, of normal tissue are more abundant than normal tissues, such as the vibration peak of the ones of tumor tissue at 3100-3500 cm region nucleic acid at 1082 cm. Another is that a peak There are more abundant spectral features in the at 968 cm is observed only in benign tissue but absorption spectrum of normal tissue than one of neither in normal nor in malignant ones cancerous tissues through comparing the second Fig 2 shows the absorption spectra of normal order derivatives of absorption curves in 900-1200 (curve I), benign(curve ID) and malignant(curve and 3100-3500cm. These features, which are ID) tissues in 1400-1750 cm region. The peak at related to certain biological activities, could be 1655 cm(corresponding to amide I bond), which used to distinguish normal tissues and diseased can be ascribed to the absorption of the C=o ones and to differentiate benign tumor and stretching vibration coupled to the in-phase malignant cancer. In 900-1200 cm region, the bending of the N-H bond [8], and the peak at enhanced absorption in tumor tissue implies that 1543 cm(corresponding to amide II bond)are the contents of primary components such as the stronger in malignant tissue but weaker in normal polysaccharides and various DNA functionalthe spectrum of malignant cancerous tissue is more complicated. There are two obvious characters shown in spectrum of diseased tissues. One is the absorption peaks shift somewhat relative to that of normal tissues, such as the vibration peak of nucleic acid at 1082 cm
1 . Another is that a peak at 968 cm
1 is observed only in benign tissue but neither in normal nor in malignant ones. Fig. 2 shows the absorption spectra of normal (curve I), benign (curve II) and malignant (curve III) tissues in 1400–1750 cm
1 region. The peak at 1655 cm
1 (corresponding to amide I bond), which can be ascribed to the absorption of the CQO stretching vibration coupled to the in-phase bending of the N–H bond [8], and the peak at 1543 cm
1 (corresponding to amide II bond) are stronger in malignant tissue but weaker in normal and benign tissues. Then, the absorption peak at 1500 cm
1 can be observed only in malignant tissue and might result from the CQC vibration of pyrrole. Two absorption peaks at 1464 and 1474 cm
1 , whose double peak structure was not reported before, emerge as shown in Fig. 2. The IR spectra in the lipid and N–H amino group absorption region from 2700 to 3600 cm
1 are shown in Fig. 3(a). The three main peaks at 2850, 2917 and 2955 cm
1 are all resulted from the stretching vibrations of the organic groups CH2 and CH3 of the acyl chains inside fatty acids [9]. The calculated second order derivatives are shown in Fig. 3(b). It is easy to see that the IR absorption spectral structures, hence the chemical compo￾nents, of normal tissue are more abundant than the ones of tumor tissue at 3100–3500 cm
1 region. There are more abundant spectral features in the absorption spectrum of normal tissue than one of cancerous tissues through comparing the second￾order derivatives of absorption curves in 900–1200 and 3100–3500 cm
1 . These features, which are related to certain biological activities, could be used to distinguish normal tissues and diseased ones and to differentiate benign tumor and malignant cancer. In 900–1200 cm
1 region, the enhanced absorption in tumor tissue implies that the contents of primary components such as the polysaccharides and various DNA functional ARTICLE IN PRESS 900 950 1000 1050 1100 1150 1200 -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Absorbance (a.u.) Wavenumber (cm-1) I II III 960 980 1060 1080 1100 0.0 4.0x10-4 3.0x10-4 2.0x10-4 1.0x10-4 -1.0x10-4 -2.0x10-4 -3.0x10-4 -4.0x10-4 -5.0x10-4 -6.0x10-4 Second Order Derivative Wavenumber (cm-1) I II III 968cm-1 1082cm-1 (a) (b) Fig. 1. IR absorption spectra in the carbohydrate absorption region (a) and their second-order derivatives (b). Curves I, II and III represent absorption of normal, benign and malignant tissues, respectively. 1400 1450 1500 1550 1600 1650 1700 1750 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Absorbance (a.u.) Wavenumber (cm-1) I II III 1655cm-1 1543cm-1 1464cm-1 1474cm-1 1500cm-1 Fig. 2. IR absorption spectra in the amide I and amide II regions. Curves I, II and III are corresponding to the absorption of normal, benign and malignant tissues, respec￾tively. 134 C. Liu et al. / Journal of Luminescence 119– 120 (2006) 132–136