(102b) Synthesis of Gold Nanokites by Temperature Controlling Method

This article describes a simple approach to gold nanokites prepared by the reduction of HAuCl₄ in the solution of β-cyclodextrin (β-CD) through controlling reaction temperature. In this approch, β-CD served as both a mild reducing agent and protective agent. However, the reacted temperature was the more important factor that controlled the anisotropic gold nanostructures with various shapes. With a fixed concentration of 0.2 mM HAuCl₄ and 0.4% β-CD, as the reaction temperature was 90^oC, there were some gold nanotadpoles (about 50 nm long) formed; as 80^oC, some branched gold nanostructures with equivalent diameter around 150 nm; as 70 ^oC, gold nanowires as long as 1μm; as 60 ^oC, gold nanokites (more than 1μm). Electron diffraction pattern (ED) suggested that these nanokites were single crystalline. UV-Vis absorption spectrum of gold nanoparticles indicated that there were anisotropic nanostures formed in the reacted solutions. The preferred noble metal nanokites may be obtained easily by this simple method.