Highly sensitive open-channels based plasmonic biosensor in visible to near-infrared wavelength

Abstract

In this paper, we numerically demonstrate a low-cost plasmonic refractive index sensor using two-sided open-channels that can operate in both visible and near-infrared region. Widely used finite element method (FEM) software is employed to characterize the sensing properties. A thin coating of gold layer is used inside the open channels of the photonic crystal fiber (PCF) to create the plasmons. It is reported that the highest wavelength sensitivity of 5000 nm/RIU with a sensor resolution of 2.0 × 10−5 RIU can be achieved at an analyte refractive of 1.38. Besides, it is also achievable to have the highest amplitude sensitivity of 396 RIU−1. The proposed sensor shows excellent linear characteristics with the highest figure of merit (FOM) of 47 RIU−1 between a refractive index of 1.33 and 1.39. Due to structural simplicity and improved sensitivity, the proposed plasmonic sensor is highly applicable in biological and biochemical analyte detections.