Laser-Induced Nanowelding of Linearly Assembled and Silica-Coated Gold Nanorods to Fabricate Au@SiO2 Core-Shell Nanowires

Au@SiO2 core shell nanowires have been successfully fabricated by irradiating infrared nanosecond pulses to linearly self-assembled and silica-coated gold nanorods. Gold nanorods have been self-assembled linearly by adding isopropanol in the absence of any assembling agents to form gold nanochains. The end-to-end assembled gold nanorods then have been directly encapsulated with uniform silica shells having tunable thickness to produce silica-coated gold nanochains. The irradiation of the nanostructures loaded on a transmission electron microscopy (TEM) grid for 5 min with nanosecond laser pulses of 1064 nm at fluence of 0.38 mJ/cm(2) has produced Au@SiO2 core shell nanowires. This is a novel and straightforward synthetic approach for the production of silica-coated gold nanowires having strong near-infrared absorption, high stability, and easily fiinctionalizable surface.