Nanogap-based dielectric-specific colocalization for highly sensitive surface plasmon resonance detection of biotin-streptavidin interactions

Yonghwi Kim, Kyungwha Chung, Wonju Lee, Dong Ha Kim, Donghyun Kim

Research output: Contribution to journalArticle

35 Citations (Scopus)


We have performed highly sensitive surface plasmon resonance (SPR) detection by colocalizing the evanescent near-fields and target molecular distribution. The colocalization is based on oblique metal evaporation to form nanogaps of a size under 100 nm without using electron-beam lithography. The concept was demonstrated by detecting siloxane-based biotin/streptavidin interactions. 50-nm nanogaps produced the largest amplification of optical signatures and two orders of magnitude enhancement of sensitivity over conventional thin film-based measurements. The enhancement is associated with efficient overlap of localized near-fields and target. Colocalized detection scheme is expected to provide clues to molecular sensitivity for SPR biosensing.

Original languageEnglish
Article number233701
JournalApplied Physics Letters
Issue number23
Publication statusPublished - 2012 Dec 3


All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

Cite this