Study Of The Sers Spectrum Of Bioactive Molecules

Surface Enhanced Raman Scattering(SERS) effect was discovered in the mid-1970s and was developed rapidly as a very important and effective spectroscopic tool for characterization and analysis with molecular adsorption on various substrates as well as the molecular interaction mechanism. In recent years, the SERS technique has been widely used in many research fields, such as life science, materials science, catalysis, and environmental chemistry. Utilization of the SERS technique based on nano-particles for studying the biomolecules can incorporate very effectively both the advantages of SERS spectroscopy and those of nanoparticles. It can greatly broaden and go deep into the applications of SERS technique in the research field concerning biomolecules. Therefore, it is necessary to synthesize property-good nanomaterials and prepare great SERS-activitive substrates. Then we can stusy effectively the structures and properties of biomolecules adsorbed on them, and furthermore reveal the mechanism about molecular interaction accompanying the formation of the adsorbed species.For this purpose, our research work includes the following aspects:(1). The elementary principles and features of Raman and SERS were summarized, and the applications in the research of biomolecules were also presented primarily.(2). Azathioprine and dopamine were selected as the representative biological molecules for our research. By using the appropriate molecular self-assembly method, azathioprine or dopamine molecules can be assembled onto the silver electrode surfaces, and then the SERS spectroscopic technique was used to characterize their adsorption. The results show that the SERS spectra of molecular adsorption change with the physicochemical parameters and conditions. Furthermore, the molecular adsorption conformations were also inferred from these SERS spectra.(3). Syntheses of gold, silver and gold-silver core-shell nanoparticles were characterized by UV and TEM techniques. Conductive glass (ITO) was selected as the substrate for assembly of these nanoparticles. The ordered nanoparticle assembly system were used as an SERS substrate to study the biological macromolecule, azurin.