Novel 3D arrays of gold nanostructures on suspended platinum-coated carbon nanotubes as surface-enhanced Raman scattering substrates

We report electrochemically controlled fabrications and the corresponding enhancement in Raman scattering of the three-dimensional (3D) gold arrays prepared on the template of platinum-coated carbon nanotubes (CNTs) by electrochemical deposition (ECD). The topography of deposited gold was varied from nanoparticles to nanowires by ECD conditions. The increasing surface area of 3D arrays of gold nanoparticles contributed to increase significantly the sensitivity of surface enhanced Raman scattering (SERS). For the same 3D arrays consisting of gold nanowires but with different surface roughness, much higher SERS activity was obtained when the surface of nanowires was rough.