Preparation Of Ag/GO Complex And Its Application In Protein Detection And Electrode Materials

Graphene oxide(GO)as an excellent load platform,it can regulate the loading state of the nanoparticles,thus providing excellent performance.In this paper,GO is used as a"semi-coated" surfactant and loading platform,Silver nanoparticles/GO composites were prepared;the composites were applied to label-free detection of protein and electrode materials.The main research contents are as follows:(1)The silver nanomaterials with different morphologies were synthesized by different methods,such as polyol reduction,hydroxylamine hydrochloride reduction and trisodium citrate reduction.The method of sodium citrate as reducing agent was mainly studied,and the synthesis technology was improved.The silver nanoparticles with irregular polyhedron size of 50-60nm were successfully synthesized.(2)The GO was prepared by Hummers two times oxidation method,and the process was optimized by adding excessive H2SO4 and controlling the feeding rate of potassium permanganate and graphite powder.The GO prepared with excellent dispersion and suspension properties.The GO characterized by transmission electron microscopy,UV spectroscopy and Raman spectroscopy.(3)Ag/GO composite substrate was prepared by introducing GO as the loading platform.By adding NaCl,the silver nanoparticles were agglomerated and loaded on the GO and formed a SERS substrate with enhanced effect.The substrate can be used to the Label-free detection of protein.The factors affecting the Label-free detection of protein were also discussed.The realization of label-free detection of protein is mainly affected by the size and morphology of the silver nanoparticles,as well as the substrate cleaning and substrate agglomeration state.The small agglomeration of the silver particles formed by the irregular polyhedron morphology of 50-60nm is more beneficial to the Label-free detection of protein by Raman enhancement.The aggregation state and surface cleaning of the substrate can be easily realized by the synergistic effect of NaC1 concentration and the semi coated stabilizer of graphene oxide.(4)The LiFePO4 was prepared by hydrothermal method and ZnMn2O4 was prepared by coprecipitation method.The Ag/GO composite was added to the electrode material according to a certain proportion.The morphology of materials was characterized by TEM and SEM.Ag composite were filled in the surface and gap of the electrode material.Electrochemical properties of the material were tested and it was found that the electrode material added with Ag/GO composite had better electrochemical performance than the single electrode material.