`The aqueous-phase synthesis of polyhedral gold nanoparticles with remarkably narrow size distribution is reported. By using a seeding growth approach, icosahedral gold particles with controllable size can be synthesized in high-yield. Citrate-capped 3.5 nm gold nanoparticles, prepared by the reduction of HAuCl4 with sodium borohydride, are used as seeds. The synthesized gold nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. The prepared gold nanoparticles show efficient surface-enhanced Raman scattering activities. (c) 2006 Elsevier B.V. All rights reserved.