Based On The Preparation Of Nano-materials For Surface-enhanced Raman Spectroscopy And Research

Au nanoparticles have a lot of attractive qualtity, such as:high electron density, dielectric property, catalytic action and so on, AuNPS can be combined with many biomacromolecule and have no effect on biological activity, meanwhile, AuNPs is provided with a series of superior optical properties, electricity nature, chemical activity and favorable biocompatibility, can be used as a reagent which can make fluorescence quenched effectly and a efficient biomolecule carrier, hence, AuNPs gain widely application in bioanalysis, besides. Research find that AuNPs have be widely researched in surface-enhanced laman scattering, surface local plasmon which is exciated lead to the compoud adsorbed on the rough metal surface electromagnetic amplification and cause the molecule adsorbed on the coarse metal surface compose the "hot spot" of laman. These "hot spot" makes the intensity have a great improved. The enhancement factor can be as high as1013, this technique take advantage of a high sensitivity and a good selectivity, besides, It has an improtant application in environment chemistry and analytical chemistry, therefore, Surface-enhanced laman scattering is a significant means which can be used to identify isomer and some chemical construction compound. SERS is a vital instrument that study solution and interface.DNA is also named deoxyribonucleic acid and a substance of carry the life information. recent years, DNA folding is a fashioned biology carrier, In our study, we have exploited DNA to synthesize some complicated, three-dimensional nanostructure, DNA act as extraordinary macromolecule substance, We link AuNPs with DNA perfectly to synthesize a number of structure which can make the signal amplify remarkablely.SiO2is a kind of semiconductor, There is no effect on SERS intensity when pack a layer SiO2outside the AuNPs, form a technique called Shell-isloated nanoparticle enhanced raman spectroscopy which utilize AuNPs used as a basis. Due to the amplification is related with distance, the thickness of SiO2is very thin, consequently, the reinforced electromagnetic fields maded by Au core have a effect on the segment beyond the SiO2, along with the change of the thickness, the intensity induced by the molecule can be changed, the research found that Au NPs with a diameter of less than10nm exhibit catalytic activity, but they cannot be used for efficient generation of SERS duo to their very small scattering cross sections, typically only Au NPs larger than20nm have sufficient plasmonic activity and provide the required SERS enhancement. However, these large, SERS-active Au NPs are not catalytically active anymore. The central dilemma is therefore that neither the small nor the large Au NPs alone exhibit both desired properties:catalytic and SERS activity. Here, we demonstrate a rational chemical approach for integrating catalytically active small Au NPs with SERS-active large Au NPs into a single bifunctional metal superstructure.Otherwise, we have also investigate that grow thorn on the Au NPs, Forming a structure resemble "see cucumber-like", owing to the rate of high surface area and the distance between the thorns is less than1nm, so it is a good basis for SERS.