An article investigating the suitability of arrays of gold coated pyramids for surface-enhanced Raman scattering (SERS) sensing applications was published in Optics Express by, among others, Nanocomp’s Ville Kontturi and Samuli Siitonen
(S. Z. Oo, S. Siitonen, V. Kontturi, D. A. Eustace, and M. D. B. Charlton, “Disposable gold coated pyramidal SERS sensor on the plastic platform,” Opt. Express 24, 724-731 (2016)
Pyramidarrays composed of 1000nm pit size with 1250nm pitch length were replicated on a plastic substrate by roll-to-roll (R2R) ultraviolet (UV) embossing. The level of SERS enhancement, and qualitative performance provided by the new substrate is investigated by comparing Raman spectrum of benzenethiol (BTh) test molecules to the benchmark Klarite SERS substrate which comprises inverted pyramid arrays(1500nm pit size with 2000nm pitch length) fabricated on a silicon substrate.
The new substrate is found to provide upto 11 times increase in signal in comparison to the inverted pyramid (IV-pyramid) arrays fabricated on an identical plastic substrate. Numerical simulation and experimental evidence suggest that strongly confined electromagnetic fields close to the base of the pyramids, are mainly responsible for the Raman enhancement factor, instead of the fields localized around the tip. Unusually strong plasmon fields are projected upto 200nm from the sidewalls at the base of the pyramid increasing the cross sectional sensing volume.
Link to full article: