Sensitivity-Enhanced Surface Plasmon Resonance Sensor Based on Zinc Oxide and BlueP-MoS2 Heterostructure

A novel design of a surface plasmon resonance (SPR) sensor based on the heterostructure of 2D nanomaterials, viz. blue phosphorus (BlueP) and molybdenum disulfide (MoS2), coupled with an adhesive layer of zinc oxide (ZnO) is presented here to enable significant plasmonic performance enhancement. The five-layer SPR system based on the Kretschmann configuration consists of ZnO sandwiched between a BK7 glass prism and gold (Au) layer, a BlueP-MoS2 heterostructure, and a sensing medium. The numerical analysis of the proposed sensor is carried out using the transfer matrix method and the sensor performance parameters; sensitivity, full width at half maximum (FWHM), and quality factor (QF) are studied at an operating wavelength of 633 nm for refractive index change in the range 1.33-1.335 RIU. The thicknesses of the Au, ZnO, and BlueP-MoS2 heterostructure layers are optimized and the sensitivity (260 degrees/RIU) and QF (48.14 RIU-1) of the proposed sensor with 48 nm Au, 6 nm ZnO, and a monolayer of BlueP-MoS2 (0.75 nm) are enhanced by 51.16% and 19.3% over the conventional SPR sensor. The rational design of the proposed SPR sensor delivering significantly large sensitivity is suited for experimental realization to deploy ZnO as an effective adhesive layer with the BlueP-MoS2 heterostructure for improved sensing performance.

Automated summary

This paper presents a novel design of a surface plasmon resonance (SPR) sensor based on a heterostructure of 2D nanomaterials, blue phosphorus (BlueP) and molybdenum disulfide (MoS2), coupled with an adhesive layer of zinc oxide (ZnO). The sensor shows significant enhancement in plasmonic performance, with improved sensitivity and quality factor compared to the conventional SPR sensor. The rational design and optimized layer thicknesses of the proposed sensor make it suitable for experimental realization and improved sensing performance.