Matrix shaped plasmonic hybrid nanostructure with direction-dependent functionality for multianalyte detection and biosensing

Abstract

Abstract A Surface plasmon resonance based hybrid nanosystem with the competence of single and multiple analytes analysis is demonstrated using a symmetry modified sensory platform for promising application in biosensing. Plasmonic properties of the designed 2 × 2 matrix system arising from higher-order plasmonic modes generated near groove positions in the structure are analyzed numerically and calibrated for enhanced sensor performance and multi-functionality. The asymmetric defect/ percentage of asymmetry (Δ) in the structure, incorporated by means of a position-wise shift of Ag nanodisc exhibits pivotal results in performance parameters, including intra channel sensitivity (S intra), channel separation factor (CH factor ), figure of merit (FOM) and Q-factor. The pairs of sensing windows of the hybrid structure show a geometric symmetry along the x and −x direction and an asymmetry along its perpendicular (y and −y). Among the symmetric and asymmetric channels, spatially resolved plasmonic modes of asymmetric channels facilitate the multi quantification of analytes in a single stimulation, whereas symmetric ones confirm the presence of the different analytes in the given specimen. With the sensor function flexible to light incidence direction, the matrix system can be effectively employed across medical diagnostics and healthcare monitoring.