Synthesis of gold nanoparticle/silica nanostructures

A novel approach is proposed to prepare organic-inorganic composite tubular structure by mineralizing silica and/or gold nanoparticle in the LbL assembled polypeptide multilayers films. Mesoporous silica (m-SiO₂) and gold nanoparticle/mesoporous silica (Au NP/m-SiO₂) tubes were prepared by subsequent calcination. The LbL assembled poly-L-lysine (PLL)/poly-L-tyrosine (PLT) multilayer film within the inner pores of polycarbonate templates acts as both a mineralizing agent and template for the formation of these materials. The as-prepared mesoporous SiO₂ and Au NP/m-SiO₂ tubes have well-defined structures. Gold nanoparticles with size smaller than 8 nm were immobilized in the silica network and the as-prepared Au NP/m-SiO₂ tubes exhibit good catalytic activity towards the reduction of p-nitrophenol. This approach may provide a facile and general method to synthesize organic-inorganic and metal-oxide nanocomposites with different composition and structures.