Preparation And SERS Properties Research Of Noble Gold And Its Core-shell Structure Nanoparticles

Due to the special electrical, optical properties, biomolecular compatibility, and goodcatalytic activity, synthesis and properties of noble metals Au particles and core-shellstructure have attracted wide attention. However, the application materials should beestablished in the controlled synthesis of nanostructures and on the foundation of itsdetailed analysis of the growth mechanism. Therefore, in order to make materials arewidely used in various fields, the design and preparation nano-materials with specialstructure and function become an urgent task.In this paper, noble metals Au nanorods have been synthesized, bimetallic Au@Agcore-shell materials, Au and semiconductor composite particles have been prepared. Theultraviolet-visible absorption, photothermal properties and SERS(surface enhance ramanscattering) enhancement effects and recyclability have been studied in relatedaspects.This subject intend to prepare a simple operation, economical, high sensitivitySERS material, which aim at to investigate the SERS effect of a single nanoparticles.The main contents are as follows:(1) With cetyltrimethylammonium bromide (CTAB) as surfactant, by changing theexperimental conditions gold nanorods with different aspect ratios were prepared by seedgrowth method, transmission electron microscopy (TEM) was used to charaterize themicrostructure of gold nanorods, the effect factors of the morphology and growthmechanism of gold bars were investigated. gold nanorods were used to surface enhanceraman scattering (SERS) materials, its sensitivity were detected using surface-enhancedRaman technology.(2) Bimetallic composite core-shell nanoparticles were prepared by two noble metals Au and Ag with better SERS performance, using sodium citrate direct reductionmethod.Changing the amount of AgNO3to realize regulation of the shell thickness.Structure and morphology of the Au@Ag particles were characterized by HRTEM, TEM,and the UV-Vis absorption properties of sample were studied by UV-Vis. Their detectivesensitivity for4-ATP molecules was characterized by surface-enhancement Ramanscattering.(3) The expensive Au particles and relatively inexpensive semiconductor materialswere composited. Compared to a separate Au, The composite materials have similarfunction and properties, but significantly decrease the cost.①Spherical gold particles with a diameter of about16nm were prepared usingformaldehyde direct reduction method. The surface of Au was wrapped by differentthickness Cu2O shell material by epitaxial growth method. Au@Cu2S core-shell particleswere obtained by further sulfide. Structure and morphology of the sample werecharacterized by SEM and TEM, the sample composition and constitution were analyzedby XPS. UV-visible absorption properties, photothermal properties of the two kindscore-shell materials were studied, and Au@Cu2O nanoparticles on the SERS detectionlimits and effects of4-ATP self-cleaning recyclability were studied. The results indicatethat the kind materials could be both SERS activity and catalytic properties functionalmaterials.②Cu2O@Au microcrystals were prepared by the in situ reduction of HAuCl4onthe surface of Cu2O, Cu2O were prepared by glucose reduction method. The materialsSERS properties were studied.The results show that the particles have a good SERSenhancement properties,1083cm-1,1594cm-1,1140cm-1,1381cm-1and1422cm-1characteristic vibration of4-ATP molecules were significantly enhanced.