Simple blood test for diagnosis of gastrointestinal and pancreas cancer using surface-enhanced Raman scattering.

Abstract

32 Background: Surface-Enhanced Raman Scattering (SERS) has been widely applicated in industrial microanalysis, and researched to apply for various fields, for example biological research. We tried to detect the SERS spectra from blood samples obtained from patients with cancers or benign diseases by using a low intensity laser beam, and compared the SERS spectra pattern among the samples from the patient group. Methods: Blood samples were obtained from patients with gastric cancer (n=30), colorectal cancer (n=20), pancreas cancer (n=5) and benign diseases (n=20). All blood samples were centrifuged at 1600g for 7 minutes, and serum samples were extracted. The serum samples were placed on the phosphor bronze chip with silver nanoscale hexagonal columns (NHCs), and SERS spectra was detected by using low intensity helium-neon red laser beam with 633 nm as wavelength. Results: SERS spectra were detected in all samples within 4 minutes from irradiation. Limiting dilution of detecting SERS was 1/1000 of serum. SERS spectra patterns were different between cancer and benign disease patients, and maximum peak level of the SERS in the samples from cancer patients were significantly higher than those from benign disease patients. There was a difference on the wavelength of Raman shifting at the peak intensity and the pattern of the SERS spectra between the samples from the patients with cancers and benign diseases. And furthermore, there was a difference on the SERS spectra pattern among the samples from the patients with gastric, colon and pancreas cancer. Additionally, it was suggested that the elements combined with the silver NHCs were histone-and-DNA complex. Conclusions: Our data suggest that our simple blood test using SERS is useful for diagnosis of gastrointestinal and pancreas cancer. We have been trying molecular analysis of the element combined with the silver NHCs by next-generation sequencer. Clinical trial information: UMIN000009818.