Fabrication of nano-rocket-tips for plasmonic nanofocusing

Nano-rocket-tip arrays were fabricated in silicon by using focused ion-beam (FIB) milling and then double-replica molded to obtain transparent polymeric tips that finally were coated with a metallic layer. The milling process was investigated under different beam conditions, which determine an aspect ratio and the radius of the tips. Simulations show that metallic coated nano-rocket tips are able to focus surface plasmons to produce important light intensity enhancement factors that can be exploited for high sensitivity molecular detection useful in biosensor, cell analysis, DNA hybridization studies, etc.