Resumen de Demonstrating the Many Possible Colors of Gold-Supported Solid Nanoparticles

Xiaoxia Zhang, Zhen Wang, Chunli Xu

• Introducing nanotechnology topics by demonstrating several colors of gold nanoparticles resulting from their size-dependent optical properties provides an easy, original, and appealing way to engage students in nanotechnology. In this classroom demonstration, solid gold nanoparticles were prepared by depositing gold nanoparticles on white solid supports, namely, TiO2, Mg(OH)2, CaCO3, Al2O3, and MgO. The color of the gold nanoparticles was changed by adjusting the type of supports or the concentrations of gold(III) solution. The gold nanoparticles exhibited many different colors, including purple, pink, gray, brown, dark red, and red. Typically, the preparations can be completed in less than 1 h, which makes this a feasible classroom demonstration.