Table 1.

Tentative assignments of the main Raman bands of saliva based on literature data^13,43–46.

Raman band (cm−1)	Tentative assignment
426	Proline (pyrrolidine ring deformation)*
528	S–S disulphide stretching band (collagen)
590	Glycerol, Cholesterol
622	Proteins (Phe), Lysozyme
640	Proteins (Tyr), Lysozyme
750	Proteins (Trp) Ring breathing mode
873	Proteins (Trp and Pro), Phosphatidylcholine
926	Proteins (Pro), glucose, Lactic acid
1000	Phe (Phenylalanine)*
1048	CO3–2, Phospholipids*
1122	Proteins (Trp), Lactic acid
1154	Phosphate present in DNA and RNA*
1275	C–C stretching mode of Proline(Pro)*
1336	symmetric deformation vibration of the CH3 group present in proteins, lipids, and other biomolecules*
1373	CH-deformation vibration of protein and lipids*
1408	Symmetric bending vibration of CH2 group of lipids*
1446	Deformation vibration of methyl group in lipids (–CH3)
1550	Proteins (Trp), Lysozyme
1602	Proteins (Phe and Tyr)
1667	Proteins (Amide I)*

Raman bands selected by Genetic Algorithm are highlighted with bold.