Ultra-high Sensitive Surface Plasmon Resonance Based Sensor with Dual Resonance

TL;DR

This paper presents an optimized surface plasmon resonance sensor exhibiting dual resonance in the near-infrared, significantly enhancing sensitivity for detecting gases and bio-chemicals across a wide range of applications.

Contribution

The study introduces a dual resonance SPR sensor with high sensitivity and explains the physical mechanism behind the dual resonance and opposite spectral shifts.

Findings

Achieves sensitivity of 460 um/RIU for gases

Achieves sensitivity of 290 um/RIU for biological samples

Dual resonance enhances differential spectral shift

Abstract

We show that for the optimized angle of incidence, the SPR based optical sensors exhibit dual resonance in the near-infrared region around which the sensor becomes exceptionally high sensitive. Both the resonances show opposite spectral shift with an ambient refractive index, increasing the differential shift by many folds. The physical reason behind the dual resonance and opposite spectral shifts are also explained using the modal analysis and the phase-matching condition. The presence of dual resonance is highly susceptible to the angle of incidence, which facilitates the sensors to work in a wide range from gaseous specimen to biological ones with extremely high sensitivity of 460 um/RIU and 290 um/RIU, respectively. The considered sensor has broader prospects for the detection of bio-chemicals and gases without changing its geometrical parameters.