Nanocups can bend light

Nanoshells, nanoeggs and nanocups. Nanoshells, consist of a spherical silica core coated with a thin gold shell and can be converted to nanoeggs by offsetting the core within the shell. When the offset of the core is greater than the thickness of the shell layer, the core pierces the shell, resulting in nanocups. Nanoeggs exhibit absorption and scattering spectra with multipolar peaks strongly red shifted relative to those of nanoshells and larger near-field enhancements. Researchers at the Hong Kong University of Science and Technology have developed a nanoegg with a hard cobalt shell surrounding a core of platinum and iron and found that it could safely deliver platinum, a known anticancer agent, to tumor cells. Nanoegg has been found to be seven times more toxic than the anticancer agent cisplatin to cancer cells. Synthesis of cobalt sulfide nanoparticles forms a hollow shell structure in the presence of nanoparticles made of iron and platinum and the resulting structures have