UC Irvine

During recent decades gold nanorod has been found very interesting due to their optical and thermal characteristics which make them suitable for different applications. Many interesting applications are optical application because of rod’s strong, special range of plasmon resonances, such as biotechnological imaging and sensing, surface-enhanced raman scattering and metamaterials, and these applications’ performances can be impaired by polydispersity and low yield of gold nanorod when using seed-mediated method. Since seed-mediate approach is the most convenient and cheap method making gold nanorod, so it is necessary to find ways to optimize this method. In this research, first, we focus on relationship between shapes of gold nanorods and several factors exist in forming process due to its unique surface plasmon resonance and try to find an effect way to optimize this formation. Second, we put an effort to explain the mechanism of whole formation of rods by designing experiments testing rods’ properties and directly observing rods through SEM. Experimental results are shown as we predicted, strong acid environment with slowly stirring during rods forming process can optimize seed-mediate approach and mechanism of it is: growth isotropically at first, when seeds’ size are up to 6nm, they change to growth anisotropically due to CTA−Br−Ag+ capping agents forcing rods growth in specific direction.