We have investigated the effect of surface roughness on the sensitivity of conventional and nanowire-based surface plasmon resonance (SPR) biosensors. The theoretical research was conducted using rigorous coupled wave analysis with Gaussian surface profiles of gold films determined by atomic force microscopy. The results suggest that, when surface roughness ranges near 1 nm, the sensitivity of a conventional SPR system is not significantly affected regardless of the correlation length. For a nanowire-based SPR biosensor, however, we have found that the sensitivity degrades substantially with decreasing correlation length. In particular, at a correlation length smaller than 100 nm, a random rough surface may induce destructive coupling between excited localized surface plasmons, which can lead to prominent reduction of sensitivity enhancement.
|Number of pages||8|
|Journal||Journal of the Optical Society of America A: Optics and Image Science, and Vision|
|Publication status||Published - 2007 Feb|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Computer Vision and Pattern Recognition