Study On Preparation And Coupling Effect Of Gold Nanorods Assemblies

In recent years, with the development of nanometer science, noble metal nanomaterials exhibitwide potentials in various technical fields due to their unique or improved properties. For the case offabrication, great efforts have been made on the synthesis of nanostructures with well-defined shapesthrough improving or developing methods. In applied sciences, the key problems on the application ofnanomaterials are focused on the building ordered assembly and functional units. In this work, basedon the research of surface plasma resonance (SPR) of gold nanorods, we carried out the controllableassembly of gold nanorods and realized the tunable optical absorption property in a large NIR spectralregion. Surface coating with SiO2provides an effective way for dealing the toxicity of and biologicalCompatibility of gold nanorods covered with CTAB. The optical properties of gold nanorods andassembles were studied by Finite Difference Time Domain (FDTD) simulations.The main content of this thesis includes the following part:1. Using a “seed” method, monodispersed gold nanorods colloids with SPR tuned in the rage of650-980nm were prepared. The synthesis parameters were optimized for the fabrication of goldnanorods with high yield. The optical absorption property and microstructure of the obtained sampleswere studied based on TEM and UV-Vis-NIR spectroscopic measurements.2. We carried out surface functionalization for gold nanorods by designing different experiments.The end-to-end assembly of the AuNRs proceeded with addition of MPA to the colloids of isolatedAuNRs. The samples were characterized by TEM and UV-Vis-NIR spectroscopy, and effects ofexperimental parameters on final results were discussed.3. A new and facile way was developed for the side-by-side linked gold nanorods assembly usingsmall molecular THF and alcohol. The samples were characterized by TEM and UV-Vis-NIRspectroscopy, and effects of experimental parameters on final results were discussed4. The optical properties of gold nanorods and assembles were studied by comparingexperimental measurements and FDTD simulations. Experimental parameters influenced on theoptical property of gold nanorods and the assemblies were studied.5. Cetyltrimethylammonium bromide (CTAB) covered around the gold nanorods was strongbiologic toxicity, it is difficult to combine systems with biomolecules. This limits greatly the possibleapplications of gold nanorods, such as biological research, medical imaging and treatment. We hereinreported our efforts in developing silica-coated gold nanorods (Au@SiO2). The silica-coating methodsand procedures were improved by a series of experiments. The changes in the optical properties of gold nanorods before and after coating, and the morphology of coating results were compared byoptical measurements and TEM observations.