Curvature effects on flexible surface plasmon resonance biosensing:Segmented-wave analysis

We investigate the effect of surface curvature on characteristics of flexible surface plasmon resonance biosensors. For simplified analysis, segmentation-based approximation of curved substrates has been conducted in a range of curvature radius |r| > 225 μm in the parallel and perpendicular light incidence with respect to the surface. The results suggest that resonance characteristics in general broaden with increased curvature due to larger momentum dispersion, the effect of which appears more prominent and direct in the parallel light incidence. Resonance shifts as a result of biosensing, such as DNA immobilization and hybridization, overall decrease with curvature and perpendicular incidence is more robust with a curvature change. The approach was extended to multi-curvature structure and finds significant fluctuation of resonance shift for parallel light incidence. The study can be of profound importance for plasmonic devices using flexible substrates and in fiber-based in vivo applications.