The Research Of ZnO/Ag Composite Substrate And The SERS Spectra Of Proteins

Recently, ZnO has attracted much attention because of its interesting optics andelectrnics properties, but its conductibility is lower compareing me-tals, so there ismore signification to prapare ZnO/metal composites. In the past few years, ZnO/Agcomplex have been many reports. However, these studies are mostly concerned withsilver nanoparticles in the ZnO films to build. Sarto prepared with a metallic silvernanoparticles ZnO films, they show that the electromagnetic shielding role throughthe silver nano-particles.They found that the compound reduced the transmission,increasing the resistance. Here we developed a reduction in situ methods,obtainingZnO/Ag composite microspheres in ZnO surface by reducting silver nitratesolution into a silver nanoparticles.Unique ZnO/Ag nanostructure materials were obtained by self-assembly of Agnanocrystals using ZnO nanoparticles as seeds. As ZnO is a kind of strong fluorescentsubstances, there is more application in markering biological. In this letter, we de-scribe a simple method to prepare the ZnO/Ag nanocomposites by trisod-iumcitrate-reduction. ZnO serves as the seed of the oxidation-reduction reaction.Surface-enhanced Ramanscattering (SERS) of4-mercaptoanilin (PATP) adsorbed onthe surface of ZnO/Ag.In order to study the SERS (surface enhanced Raman scattering) spectra of proteinsand make sure whether western blotting SERS could apply to catalase, we studied theSERS of catalase from beef liver. Two methods were used to perform SERS oncatalase. Method I: Catalase was adsorbed on Ag colloid. Method II: Firstly, catalasewas adsorbed on nitrocellulose membrane. Then, the membrane was immerged in Agcolloid. The result showed that the SERS obtained from nitrocellulose membrane wasmore excellent than the SERS obtained from Ag colloid. Furthermore, this methodcan be used in the research of Proteomics.We studied the SERS of coenzyme I (Nicotinamide adenine dinucleotide, NAD) to provide data for studying the interaction between NAD and proteins. The SERSspectra of NAD obtained on Ag colloid, Ag core-Au shell, Ag-Au self-assembledfilms and Ag/CdTe nanocomposite were analyzed and compared. Especially the SERSstudy of NAD obtained on Ag/CdTe composite was reported for the first time. It wasproved that Ag/CdTe nanocomposite can be used as SERS substrate.