Gram-scale synthesis of soluble, near-monodisperse gold nanorods and other anisotropic nanoparticles.

An aqueous surfactant-based colloidal chemical method is reported for the synthesis of anisotropic noble-metal nanoparticles on the milligram to multigram scale. Fine control of the nucleation-growth kinetics and rodlike micelle-induced breaking of symmetry at the early stage of particle growth are responsible for high-quality anisotropic nanoparticles. Near-monodisperse gold and silver nanorods, spheroids, nanowires, platelets, or cubes of 4-50 nm dimension and controllable aspect ratio can be prepared. The method may also be extended to semiconductor systems.