Performance Analysis of Surface Plasmon Resonance Sensor Having Multi-layer Structures of MoS2 and Graphene in NIR-region

Abstract

This paper reported a performance analysis of surface plasmon resonance (SPR) sensor using Silver (Ag) as a plasmonic material having different layer structures of 2D materials in Near Infrared (NIR) region. Most of the traditional SPR sensors are limited to visible light range only. In this paper, multilayer-structure of 2-D materials such as Graphene and molybdenum disulfide (MoS2) along with Ag is investigated. 2-D materials are capable to enhance the efficiency of the sensor and can also protect Ag from oxidation. Present work investigated the effect of multilayer coating of 2-D materials on either side of a plasmonic material (Ag). For that Single-layer, two-layer and three-layer structure are analyzed at 750 nm wavelength. Performance of the sensor is analyzed by measuring the sensitivity, maximum value of Rminand full-width-at-half-maximum (FWHM) in the response with RI of various analytes. Air, Water, Methanol and Urea are used as analytes. Range of refractive index is varied from 1.0 to 1.4852 of analytes. The results show that maximum of Rmin 4.83 $x$ 10−5, 3.0 $x$ 10−3 and 8.55 $x$ 10−3 is obtained with three-layer structure. Limit of detection with three-layer structure is obtained 0.0760 RIU for air, water, methanol and urea as a sensing medium, respectively. Maximum of Rmin, Sensitivity and FWHM increased as the number of layers of 2D materials added to the structure. Obtained results show that the maximum sensitivity 73.149°/RIU is achieved for Ag with three-layer structure at 750 nm, which implies the proposed SPR sensor is suitable for various analytes detection including biochemical and bio-molecule detection.