Jia Li-Hua, Wang Yi-Ding, Sun Cheng-Lin, Li Zhan-Long, Li Zuo-Wei, Wang Li-Jun
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2009 Oct;29(10):2686-8.
Raman spectrum is an important and effective method for the study of biological molecules in water. Measuring the Raman spectra for biological molecules in water, however, is very difficult because of the small Raman scattering cross section and the high electronic excitation energy of water molecules. In the present paper, the authors applied both technologies of liquid-core optical fiber and the resonance Raman spectra, then the intensity of Raman spectra was enhanced to a great extent. In this experiment, we chose the laser wavelength 514.5 of Ar+ ion laser as excitation laser, because we could obtain the maximal intensity of resonance Raman spectra at this wavelength. The experiment results show that, for the trace inspecting study of beta-carotene biological molecules in water, the concentration in the range of 10(-7)-10(-9) mol x L(-1) can be detected by quartz liquid-core optical fiber and the concentration in the range of 10(-9)-10(-10) mol x L(-1) by Teflon liquid-core optical fiber. The detecting utmost will be further reduced if improving the quality of optical fiber.
