title: Sensitivity analysis of a nanowire-based surface plasmon resonance biosensor in the presence of surface roughness.
abstract: 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.
authors.affiliation: School of Electrical Engineering and Computer Science, Seoul National University, Seoul, Korea.
authors.forename: Kyung Min
authors.initials: KM
authors.lastname: Byun
authors.forename: Soon Joon
authors.initials: SJ
authors.lastname: Yoon
authors.forename: Donghyun
authors.initials: D
authors.lastname: Kim
authors.forename: Sung June
authors.initials: SJ
authors.lastname: Kim