title: Effect of surface roughness on the extinction-based localized surface plasmon resonance biosensors.
abstract: We investigated the effect of surface roughness on the sensor performance of extinction-based localized surface plasmon resonance (LSPR) biosensors. The sensor measures resonance wavelength shifts in transmittance caused by biomolecular interactions that are amplified by periodic nanostructures. The numerical computation was conducted using rigorous coupled-wave analysis with Gaussian random surface profiles. The results suggest that, when a surface has a roughness smaller than 2 nm in height deviation, the sensitivity of a LSPR biosensor is not significantly influenced regardless of correlation length (CL). However, we found that the extinction peak amplitude and curve width are affected substantially by a decrease in CL. At a less than 100 nm CL, surface roughness can induce interference between localized surface plasmons excited by the surface and nanowires, which can lead to major degradation of sensor performance.
authors.affiliation: Department of Biomedical Engineering, Kyung Hee University, Yongin, South 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
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004563:Electrochemistry; D004867:Equipment Design; D053768:Metal Nanoparticles; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D053770:Nanowires / Q000737:chemistry; D016011:Normal Distribution; D055095:Optics and Photonics; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods; D013499:Surface Properties