A localized surface plasmon resonance (LSPR) biosensor using surface relief nanostructures was investigated to evaluate the importance of target localization on the sensitivity enhancement. The LSPR device was modeled as periodic metallic nanowires with a square profile on a gold film and the target as a self-assembled monolayer in buffer solution. The numerical results using rigorous coupled-wave analysis and the finitedifference time domain method demonstrated localized plasmonic fields induced by the surface nanostructure from which the effect of target localization on the sensitivity was quantitatively analyzed. Interestingly, it was found that target localization on nanowire sidewalls improves sensitivity significantly because of strong overlap with localized plasmonic fields. An LSPR structure optimized for a localized target on sidewalls provides sensitivity enhancement per unit target volume by more than 20 times in water ambience.
|Number of pages||8|
|Journal||Journal of the Optical Society of America A: Optics and Image Science, and Vision|
|Publication status||Published - 2009 Apr 1|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Computer Vision and Pattern Recognition