Preparation of metallic triangular nanoparticle array with controllable interparticle distance and its application in surface-enhanced Raman spectroscopy

This paper reports a facile method for fabricating metallic triangular nanoparticle array with controllable interparticle distance, based on a combination of nanosphere lithography, reactive ion etching and physical sputtering technique. Light transmission spectra of the metallic triangular nanoparticle arrays with a series of interparticle distances are measured, which show a surface plasmon resonance whose position is observed to shift to longer wavelength for the polarization direction parallel to the long particle pair axis with decreasing the interparticle distance. With this structure as surface-enhanced Raman scattering substrate, the Raman signal is strongly enhanced and shows high dependence on the interparticle distance. The controllable interparticle distance and large-area ordered array of the substrate suggest its promising application in surface-enhanced Raman spectroscopy. (C) 2013 Elsevier B.V. All rights reserved.