Triangular nanofrarnes made of gold and silver

Silver nanoprisms (similar to74-nm edge length) were etched with HAuCl4 to generate gold-silver alloy framework structures. Interestingly, these triangular nanoframes possess no strong surface plasmon bands in the ultraviolet or visible regions of the optical spectrum. By adding a mild reducing agent, L-ascorbic acid, gold and silver ions remaining in solution can be reduced, resulting in metal plating and reformation of nanoprisms. The extent of the back-filling process can be controlled, allowing one to form novel prisms with nanopores. This back-filling process is accompanied by a regeneration of the surface plasmon bands in the UV-vis spectrum.