The Preparation Of Gold Shell Nanostructure And Study Of Surface-enhanced Raman Scattering

Fabrication and research of different shapes of gold nanomaterials have recentlyreceived increasing attention, due to their tunable and unique characters in optics andcatalysis. Gold nanoshell has become a hot topic because of its great potentialapplication in Surface-enhanced Raman scattering (SERS). It was thought that a keyfactor of sensitivity of SERS is the roughness of subtrate, thus the investigation ofdifferent substrate can expand the application of SERS.The aim is developing new methods for gold shell preparation, and serving assubstrate of SERS with high SERS sensitivity and stability. Different shape of goldshell was synthesized via templating method and self-assembly. Rodamine B (RhB)was used as Raman probe to investigate the SERS sensitivity of gold shell. The mainworks and the conclusions are as follows:1. Stable and uniform-sized gold colloids (3.23nm、4.75nm、12.56nm、18.76nm)were prepared by wet chemistry methods. Silica nanospheres about300nm wereprepared through improved st ber method, then they were functionalized by aminogroups (NH2-SiO2). Gold seeds were attached to the NH2-SiO2, Au spiky shell wasobtained by dropping SiO2-Au (seed) in growth solution. RhB was used as Ramanprobe. Several times of SERS signal enhancement was obtained by using spicky goldshell.2. Fe3O4was synthesized by solvothermal process, afterwards a silica layer wasdeposited on the surface of Fe3O4. Two different shape of gold shells were obtained byusing different size of gold seeds. The mechanism of shape growth was proposed.These nanocomposites can be used as magnetic substrate in SERS application.3. Gold nanoparticles with different shapes were prepared (spherical shape, rod,triangle-shape). These nanoparticles were immobilized on silica nanosphere throughself-assembly. The distribution of gold nanoparticles on the surface of silica sphere andthe optical property of composites were studied.