Hollow Gold Nanospheres: Growth Morphology, Composition and Absorption Characteristics

Gold hollow nanospheres (GHNs) were synthesized by using various stoichiometric ratios of chloroauric acid and cobalt nanoparticles as sacrificial templates through redox reaction of sodium borohydride. The self-assembly and crystallization process of GHNs were represented. The size of GHNs was dependent on the concentration of sodium citrate, sodium borohydride, and chloroauric acid. The composition of hollow nanospheres was analyzed for each growth strategy. It was notable that the core of the nanoshells contains significant traces of Co elements. The surface plasmon resonance peak of these hollow nanospheres shifts over 140 nm with varying nanostructure sizes. The GHNs are extremely useful for various molecular sensing applications.