Synthesis Of Au/Ag Micro-/Nanostructures And Study Of Their SERS Properties

As one of the most popular directions in the current scientific field,noble-metals micro-/nanostructures exhibit great potentials in synthetic chemistry,materials science,physics,biology and medicine.Noble-metal micro-/nanostructures have unique advantages in the field of surface-enhanced Raman scattering(SERS)due to their large specific surface area and unique surface structure.Herein,noble-metal micro-/nanostructures with different morphologies were fabricated via novel strategies and their application in SERS enhancement was investigated.The details are as follows:(1)Spontaneous growth of the three-dimensional Au(Ag)microstructures on polymer brushes grafted graphene oxide.In our strategy,p H-responsive P4VP brushes and thermo-responsive PNIPAM brushes were grafted on GO,respectively.During the reaction,GO served as a reducing agent,and polymer brushes acted as"morphology control agents".The changes in temperature and p H can be used to control the shape and size of noble-metals particles.Finally,the application of the prepared polymer brushes-grafted-GO/noble-metal particles composites in surface-enhanced Raman spectroscopy(SERS)were investigated.(2)Fabrication of micro-/nanocubes with different surface structures using cubic Ag(NH₃)₂NO₃ crystal as templates.First,well-defined cubic Ag(NH₃)₂NO₃ crystal were obtained as a template by a fast and simple evaporating process of the silver ammine complex solution.Ag(NH₃)₂NO₃ microcubes were then reduced to hollow silver microcubes,nanosheet-intercalated silver microcubes,and nanoporous silver microcubes via a liquid-solid interfacial reduction process using glucose,hydrogen peroxide,and sodium borohydride as reducing agent correspondingly.In trisodium citrate aqueous solution,micrometer-sized Ag(NH₃)₂NO₃ cubes broke up into silver citrate nanocubes which could serve as sacrificial templates to yield hollow porous silver citrate nanocubes.The SERS performances of the as-prepared silver micro/nanocubes were investigated using Rhodamine 6G as probe molecules.Due to the unique morphologies obtained through this fabrication method,the as-prepared hollow porous silver nanocubes exhibited ultra-high SERS sensitivity.