We report about a simple, versatile, low-cost and high-throughput methodology for the size-selected growth of SiO 2 nanowires (NWs) on surfaces and on their surface decoration by Au nanoparticles (NPs). In contrast to a standard method involving the solid state reaction of thin Au films on Si at high temperature in the presence of trace amount oxygen (resulting in the formation of SiO 2 NWs with a very high dispersion in diameters), the proposed method involves the same reaction between size-selected colloidal Au NPs and the Si substrate. By microscopic analyses we demonstrate that, by such a method: 1) NWs of very low diameter can be grown with respect to those originating by films; 2) the size dispersion of the obtained NWs is much lower with respect to those originating by films; 3) the NWs' diameter can be finely tuned by controlling the colloidal NPs starting size; 4) it is possible to decorate such NWs by …