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

Area of Science:

• Optoelectronics
• Nanotechnology
• Biomedical Engineering

Background:

• Flexible surface plasmon resonance (SPR) biosensors offer potential for portable and in vivo diagnostics.
• Understanding the influence of substrate curvature on SPR sensor performance is crucial for device optimization.

Purpose of the Study:

• To investigate the effect of surface curvature on the resonance characteristics of flexible SPR biosensors.
• To analyze how curvature impacts biosensing performance, specifically DNA immobilization and hybridization detection.

Main Methods:

• Employed segmentation-based approximation for curved substrates with curvature radii |r| > 225 μm.
• Analyzed sensor response under both parallel and perpendicular light incidence.
• Extended the analysis to multi-curvature structures.

Main Results:

• Increased surface curvature leads to broader resonance characteristics due to enhanced momentum dispersion.
• The effect of curvature on resonance broadening is more pronounced with parallel light incidence.
• Biosensing resonance shifts (DNA immobilization/hybridization) decrease with increasing curvature; perpendicular incidence shows greater robustness to curvature changes.
• Multi-curvature structures exhibit significant resonance shift fluctuations under parallel incidence.

Conclusions:

• Surface curvature significantly alters SPR biosensor performance, affecting resonance properties and sensing sensitivity.
• Perpendicular light incidence offers improved stability against curvature variations in biosensing applications.
• Findings are vital for developing advanced plasmonic devices on flexible substrates and for fiber-based in vivo sensing.