Raman Spectroscopic Studies On Structural Biology

Raman spectroscopy, as a nondestructive spectral technique, provides largeinformation on the chemical structure of the probed substance, and therefore usuallyserved as a well-established tool for investigating the complex biological systems. Inthis thesis, Raman spectroscopy was employed to study the components and structureof biomacromolecule, and the date were analyzed by ANOVA and IDA. We discussed theinteraction mechanism of gold nanoparticles with intracellular components andsupposed one possible binding site. In addition, we also investigated the labelimmunoassay based on SERS, and used this method to study living cell. The aim wasto make gold nanoparticles to target the object. The details are the followings:(1) Confocal micro-Raman spectroscopy was used to study the characters of monkey cerebral cortex. The study indicates the Raman spectra are different for the different age group, which suggests that the fat content is different in the different age group, and the difference between the different regions was compared. In addition, statistical analysis, including of analysis of variance (ANOVA) and linear discriminate analysis (LDA), was performed on the four Raman peaks at1313cm-1,1338cm-1,2885cm-1,2932cm-1.. The differentiation accuracy was92.6%and89.8%.(2) The SERS of DNA and adenine in the presence of anions were investigated, and the interaction mechanism of silver nanoparticles (SNPS) with DNA was studied. The obvious changes in the Raman peaks for adenine (732cm-1and1333cm-1) of DNA suggest that SNPS may interact with DNA by the hydrogen bond to N7position of adenine. The SERS of Adenines were also investigated for validated the above discussion.(3) The SERS of breast cancer cell incubated with silver colloids and gold colloids were investigated. The results indicated there were obvious differences on different SERS substrates. The components of DNA were enhanced on silver substrate whereas the component of protein were enhance on gold substrate. We supposed the gold nanoparticles interact with phenylalanine of protein mainly through the binding site at the COOH group.(4) A label immunoassay method based on SERS using4,4’-dipyridyl as the probe was investigated. The result showed high signal-to-noise ratio and some questions to influence the results were discussed in detail. In addition, the method was used to explore the interaction of immunogold with component in living cell was also investigated by SERS. The results showed that labeled immunogold interacted with the target with cell.