| Autor: |
Shirmohammad M; Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada.; Imaging Unit, Integrative Oncology Department, BC Cancer Research Institute, Vancouver, BC V5Z 1L3, Canada., Short MA; Imaging Unit, Integrative Oncology Department, BC Cancer Research Institute, Vancouver, BC V5Z 1L3, Canada., Zeng H; Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada.; Imaging Unit, Integrative Oncology Department, BC Cancer Research Institute, Vancouver, BC V5Z 1L3, Canada.; Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC V5Z 4E8, Canada. |
| Abstrakt: |
Raman enhancement techniques are essential for gas analysis to increase the detection sensitivity of a Raman spectroscopy system. We have developed an efficient Raman enhancement technique called the collision-enhanced Raman scattering (CERS), where the active Raman gas as the analyte is mixed with a buffer gas inside the hollow-core photonic-crystal fiber (HCPCF) of a fiber-enhanced Raman spectroscopy (FERS) system. This results in an enhanced Raman signal from the analyte gas. In this study, we first showed that the intensity of the 587 cm -1 stimulated Raman scattering (SRS) peak of H 2 confined in an HCPCF is enhanced by as much as five orders of magnitude by mixing with a buffer gas such as helium or N 2 . Secondly, we showed that the magnitudes of Raman enhancement depend on the type of buffer gas, with helium being more efficient compared to N 2 . This makes helium a favorable buffer gas for CERS. Thirdly, we applied CERS for Raman measurements of propene, a metabolically interesting volatile organic compound (VOC) with an association to lung cancer. CERS resulted in a substantial enhancement of propene Raman peaks. In conclusion, the CERS we developed is a simple and efficient Raman-enhancing mechanism for improving gas analysis. It has great potential for application in breath analysis for lung cancer detection. |
