“…As shown in Figure 6, the Raman spectrum of the HGIN tissues exhibits significant peaks at 826 cm -1 , 838 cm -1 (amine deformation vibrations), 849 cm -1 , 861 cm -1 , 875 cm -1 (tryptophan), 889 cm -1 , 987 cm -1 , 1101 cm -1 , 1171 cm -1 , 1209 cm -1 , 1235 cm -1 , 1253 cm -1 (C-O4 aromatic stretching), 1324 cm -1 , 1413 cm -1 , and 1562 cm -1 , while the Raman spectrum of the adenocarcinoma tissues displays significant peaks at 820 cm -1 (structural protein modes of tumors), 849 cm -1 , 861 cm -1 , 875 cm -1 , 887 cm -1 , 948 cm -1 (singlebond stretching vibrations of the amino acids proline and 3 Gastroenterology Research and Practice valine and polysaccharides), 977 cm -1 , 1102 cm -1 , 1171 cm -1 , 1209 cm -1 , 1236 cm -1 , 1293 cm -1 , 1323 cm -1 , 1413 cm -1 , 1517 cm -1 , 1531 cm -1 (carotenoid, absent from the normal tissue spectrum), and 1562 cm -1 . The assignments for the peaks are given in Table 1 [14][15][16][17][18][19][20].…”