Here we present a surface based on double-layered nanoparticle stacks suitable for spectro-electrochemical applications. The structure is formed on a continuous gold layer by a two-dimensional periodic array of stacks of gold and tantalum pentoxide nanodisks. Reflection spectra in the visible wavelength region showed the multiple-resonant nature of surface plasmon (SP) excitations in the nanostructure, which is in good agreement with simulations based on a finite-difference-time-domain method. The multiple SP resonances can be tuned to various wavelength regions, which are required for simultaneous enhancement at excitation and emission wavelengths. Cyclic voltammetry measurements on the nanostructure proved the applicability of electrochemical methods involving interfacial redox processes.
© 2012 Optical Society of America
Original Manuscript: June 28, 2012
Revised Manuscript: July 20, 2012
Manuscript Accepted: July 20, 2012
Published: August 24, 2012
Pinar Frank, Johannes Srajer, Andreas Schwaighofer, Asmorom Kibrom, and Christoph Nowak, "Double-layered nanoparticle stacks for spectro-electrochemical applications," Opt. Lett. 37, 3603-3605 (2012)