Nano-pillar structure for sensitivity enhancement of SPR sensor

We report on a method to increase sensitivity of SPR (Surface Plasmon Resonance) sensor using nano-pillar structures as a protein adhesion site. The dense and tall nano-pillar array increases a virtual protein adhesion area within an SPR electromagnetic field (EMF) so that an SPR dip shift increases compared with a conventional SPR sensor. Fabricated silica nano-pillar chip with 200-nm-pitch and 570-nm-height pillar array was assembled with an optical prism with an Au film, and sensitivity enhancement for protein measurement by the nano-pillar was examined. The SPR measurement result exhibited a significant dip shift increase, about ten folds of that of the normal SPR device. The nano-pillar SPR has a potential of increasing sensitivity of SPR in detecting proteins.