Surface Plasmon Catalyzed Reaction And Surface Enhanced Raman Spectroscopic Studies

Since the discovery of surface-enhanced Raman spectroscopy(SERS),it has been applied widely in surface analysis,interface reaction detection,and so on due to its high sensitivity up to single molecular level.The SERS effect was originated from the surface plasmon resonance around the metal nanostructures and it allowed the dramatic enhancement of the Raman signal of probes located inside of surface plasmon.It also induced the occurrence of abnormal surface reaction.In this thesis,based on the preparation of SERS active Au nanoparticles substrates,the reaction catalyzed by surface plasmon catalysis was investigated accordingly.The hyphenation of HPLC and SERS was developed to on line monitor the Suzuki coupling reaction.The main results were listed as follows:(1)Exploring the reaction condition of C-C coupling reaction catalyzed by surface plasmon on Au surface and developing SERS as a powerful tool for monitoring this reaction.The surface plasmon catalyzed reaction of t BuCl and ethanol was carried out on the surface of Au nanoparticles monolayer film under the irradiation of laser.The influence of substrate composition,solution pH,solvent and power of laser on the C-C coupling reaction was investigated.The GC-MS,HPLC and TLC were employed to determine the structure of the products.The results revealed that final product of surface plasmon catalysis reaction was 4-ethyltoluene in the neutral or acidic ethanol solution.Moreover,the substitute group to the benzene was depended on the solvent.It suggested that ethanol not only acted as solvent but also participated in the reaction.(2)Developing the hyphenation of HPLC and SERS for on line monitoring the Suzuki coupling reaction as well as separating and detecting of the products from the reactants.The Suzuki reaction of phenylboronic acid and 3-bromopyridine was served as model system for verifying the performance of the integration functions of separation from HPLC and ultrasensitive detection from SERS.The structures of main and side products were determined and the results were verified by NMR and HRMS.It demonstrated that the hyphenation of HPLC-SERS could be developed as a promising tool for on line monitoring the processes of organic reaction.