研究了皮疹患者和健康人血清的表面增强拉曼光谱。结果表明: 皮疹患者血清中蛋白质主链酰胺Ⅰ的谱线出现在1 648 cm^-1处,而在健康人血清中此峰消失。蛋白质侧链C—S键扭曲构象的谱线637 cm^-1的相对强度增加了23%,而反式构象的谱线725 cm^-1的相对强度减少了60%,说明C—S键的反式构象部分转成扭曲构象,表明皮疹患者血清中蛋白质的有序结构发生变化。类脂物特征峰1 449 cm^-1的相对强度增加了近一倍,D-甘露糖的谱线1 099 cm^-1消失,表明患者血清中糖蛋白、糖质发生了变化。这些拉曼特征峰为皮疹的诊断以及生化机理研究提供了有力的实验依据。最后用主成分分析(PCA)方法对健康人和皮疹患者血清的表面增强拉曼光谱进行分析,发现皮疹患者血清的主成分分布相对健康人较分散,并且此方法能准确的区分开这2种血清。
The SERS spectra of serums from the healthy persons and rash patients were measured. In the serum of rash, the band of amide Ⅰ appeared at 1 648 cm^-1, while this peak vanished in healthy serums. The relative intensity of 637 cm^-1 assigned to the gauche conformation of C-S increased 23% and the band at 725 cm^-1 corresponding to anti-conformation decreases 60%. These indicate that the structure of the protein has changed in serums from the rash patients. The relative intensity at 1 449 cm ^-1 assigned to the lipids increased nearly one time. The band at 1 099 cm ^-1 assigned to the Man-D vanished, indicating that the contents of lipids, glucide and protein increased in rash patients. These results may offer a powerful experiment basis for rash diagnosis and biochemistry mechanism study. The multivariate statistical methods of principal component analysis (PCA) were also used to analyze the SERS of the serums from healthy persons and rash patients, it can be seen that the regional distri bution of rash is wider than healthy volunteers, showing that these serums can be discriminated by PCA.