Uniform and controllable preparation of Au-Ag core-shell nanorods using anisotropic silver shell formation on gold nanorods.

Anisotropic and controllable silver shell formation on gold nanorods was realized in a micellar solution of hexadecytrimethylammonium chloride. Uniformity of the anisotropic Au-Ag core-shell particles contributes separation of four extinction bands. The ability to manipulate the shapes and sizes of these nanoparticles offers a wide-range control of the surface extinction from the visible to the near infrared regions (450-800 nm).