Reserch On Blood Surface-enhanced Raman Spectroscopy Of Colorectal Cancer Patients

Surface-enhanced Raman spectroscopy (SERS) has become one of the most popular research techniques in the field of international biomedicine. With a view to the current clinical demand, in this thesis, the SERS technique with high biological detection sensitivity combined with statistical method was employed for human serum analysis in order to develop a non-invasive, rapid, objective and accurate detection method for colorectal cancer. The main research results as follows:1. Silver nanoparticle based surface-enhanced Raman spectroscopy was applied to analyze the blood serum from colorectal cancer patients (n=38) and healthy volunteers (n=45). Using PCA-LDA multivariate analysis, we were able to differentiate colorectal cancer from normal with diagnostic sensitivity of81.6%and specificity of75.6%, indicating silver nanoparticle based SERS can be used for colorectal cancer detection.2. Combining membrane electrophoresis with Ag-SERS, we try to explore the possibility of developing a novel method for serum protein analysis for cancer detection. The results from this exploratory study showed serum albumin and globulin based SERS analysis combined with PCA-LDA can achieve a diagnostic sensitivity of both84.2%and specificity of80%and75.6%, respectively. Compared with untreated serum-SERS technique, the serum protein-SERS can achieve better diagnosis effect.3. A receiving light polarized SERS method was firstly developed for blood serum biochemical analysis with the aim to develop a accurate blood test for non-invasive colorectal cancer detection. The diagnostic performance was achieved by erective linear polarizer direction (0°):a sensitivity of89.5%and specificity of93.3%, while with the horizontal linear polarizer direction (90°):a sensitivity of100%and specificity of84.4%. These results further demonstrate that polarized SERS yield a better diagnostics accuracy than the regular SERS in serum detection.4. In view of gold nanoparticle capable of better biocompatibility, gold nanoparticle based SERS was applied to analyze the blood serum from colorectal cancer patients and healthy volunteers. Using PCA-LDA multivariate analysis, we were able to differentiate colorectal cancer from normal with a diagnostic sensitivity of97.4%and specificity of100%, indicating great promise for developing gold nanoparticle based SERS serum analysis combined with PCA-LDA-based diagnostic algorithms into a clinical tool for non-invasive detection and screening of colorectal cancers.