Profile effect on the feasibility of extinction-based localized surface plasmon resonance biosensors with metallic nanowires

We investigate the effect of the cross-sectional profile of an array of metallic nanowires on the feasibility of a localized surface plasmon resonance (LSPR) biosensor. Calculations were performed using rigorous coupled-wave analysis with an emphasis on the extinction properties of the LSPR structure. The results indicate that the nanowire structure, particularly that of a T-profile, delivers an extremely linear sensing performance over a wide range of the target refractive index with much enhanced sensitivity. The extinction-based LSPR structure also involves a relatively large dimension and thus is expected to provide a feasible biosensor using current semiconductor technology.This work was supported by the Science Research Center and Engineering Research Center program of the Ministry of Science and Technology of the Korea Science and Engineering Foundation (KOSEF) (R11-2000-075- 01001-1). D. Kim acknowledges the support by KOSEF through the National Core Research Center for Nanomedical Technology (R15-2004-024-00000-0) and by the Korea Research Foundation Grant funded by the Korean government (MOEHRD) under KRF-2005-205-D00051