Metal Nanoshells having partial coverage of a substrate or core particle and methods of making them are provided. A method of making a partial metal nanoshell preferably includes asymmetrically confining a substrate particle and selectively layering a metallic material over the substrate particle according to the asymmetry. Confining the substrate particle may include attaching it to a support defining an exposed portion and a contact portion. The method may include either chemically modifying the substrate particle. The solid angle of coverage of the partial metal nanoshell may be influenced by the nature of the chemical modification, such as alternatives of activating and passivating the exposed portion.