The Application Of Raman Spectroscopy In The Study Of Three Kinds Of Analgesic Drugs

Raman spectroscopy is a kind of scattering spectrum produced by light interacting with the particles, we can analyse and identify the related substances or molecules by using it and its application range is very extensive including chemical, biology, environmental science and so on. Surface enhanced Raman spectroscopy (SERS) is the great enhancement of Raman scattering signal of molecules on a rough metallic surface (it usually is silver). we can obtain comprehensive information about molecules by combing with them to study the vibration of molecules and the way of the combination with metal nanoparticles. In this article, three kinds of common analgesic drugs were studied on the basis of detailed analysing and summarizing interrelated theories and applications of Raman spectroscopy and SERS combining with Infrared spectroscopy. The common analgesic drugs contains the Hesperetin and the Indomethacin belonging to the anti-inflammatory analgesic drugs and the Levo-tetrahydropalmatine what belongs to the category of nerve analgesics. The concrete research contents are as follows:The first chapter is the introduction of Raman spectroscopy. Surface enhanced Raman spectroscopy, Density functional theory(DFT), including the principle, characteristics and main application.The second chapter mainly introduces the preparation of SERS substrate. This paper explored two kinds of silver nanoparticles which can both gets better effect and the two substrate can detect the substance no matter what is water-soluble substances or volatile organic solvent series material. The substrates were also characterizated in this text.The spectral properties of Hesperetin and its inclusion compound were researched in this chapter. Hesperetin is an important anti-inflammatory drugs, the inclusion compound which is formed by Hesperetin and β-CD expanded the application of it in clinical medicine. The chapter studied the molecular vibration spectrum of Hesperetin, β-CD and inclusion compound, and proved the combination style of the two molecules.In the fourth chapter, the spectral properties of Indomethacin was analyzed by using Infrared spectrum (IR), Normal Raman spectra(NRS), SERS combined DFT, and the theoretically calculated spectra were well agreement with the obtained experimental spectra. A good SERS signal of Indomethacin were got on the first silver nanoparticles substrate surface in experiment, the adsorb style of Indomethacin molecular on silver nanoparticles substrate surface was inferred by analyzed SERS data and the the optimum concentration was 1.0×10-3 mol/L proved on experiment of concentration exploration.In the fifth chapter, the spectral properties of drug Levo-tetrahydropalmatine was studied by using IR, NRS, SERS combined DFT, and the theoretically calculated spectra were very close to the obtained experimental spectra. This drug can get good signal on the second silver nanoparticles substrate surface, the adsorption mode of it on metal substrate was deduced through observing changes of peak vibration.