Abstract

A biosensor platform based on the plasmonic resonance of graphene in the terahertz (THz) range (0.1 to 10 THz) is designed and investigated. The initial design is to create a nanofluidic channel as a sensing layer in the substrate of a biosensor grounded by metal. The sensor consists of a rectangular graphene patch over the substrate, which can be fed by either an external near-field source or an antenna. The presence of molecules in the nanosensing layer causes small changes in the channel’s properties, detectable through the scattering parameters of the designed biosensor. Since biomolecules are poorly absorbed in the initial biosensor, it can be grounded by a graphene sheet that is the same size as the graphene sheet over the substrate, which results in a performance improvement of the biosensor. It is shown that, by increasing the number of graphene sheets between the ground and the patch, high absorption occurs that enhances the sensitivity of the initial surface plasmon resonance THz biosensor. With varying refractive index of the sensing layer (Ns) in the range of 1.3–1.6, the proposed biosensors are investigated and compared with the initial biosensor. It is shown that by applying a graphene sheet between the two graphene sheets in the substrate, a maximum sensitivity of 8470 nm/RIU is achieved, which is a significant improvement, and also a sensitivity improvement of 4130 nm/RIU is achieved at ${{\rm Ns}} = {1.3}$. In the final section, it is shown that changing the substrate material from silicon (Si) to silica (${{\rm SiO}_2}$) brings a significant sensitivity enhancement in the proposed biosensor with three graphene sheets, which accounts for 15410 nm/RIU in the best scenario.

© 2021 Optical Society of America

Sensitivity enhancement of a graphene–barium titanate-based surface plasmon resonance biosensor with an Ag–Au bimetallic structure in the visible region

Lili Liu, Mei Wang, Lipeng Jiao, Ting Wu, Feng Xia, Meijie Liu, Weijin Kong, Lifeng Dong, and Maojin Yun
J. Opt. Soc. Am. B 36(4) 1108-1116 (2019)

FEM analysis of a λ³/125 high sensitivity graphene plasmonic biosensor for low hemoglobin concentration detection

Sevda Seyyedmasoumian, Asma Attariabad, and Ali Farmani
Appl. Opt. 61(1) 120-125 (2022)

Highly sensitive crumpled 2D material-based plasmonic biosensors

Vahid Faramarzi, Vahid Ahmadi, Michael T. Hwang, and Peter Snapp
Biomed. Opt. Express 12(7) 4544-4559 (2021)

Enhanced sensitivity of a surface plasmon resonance biosensor using hyperbolic metamaterial and monolayer graphene

Jinjuan Gao, Qun Zu, Shicai Xu, Wen Yang, Jingwen Feng, Runcheng Liu, Zhipeng Zha, Qianqian Peng, Weiwei Yue, Yanyan Huo, Shouzhen Jiang, and Xiuwei Fan
Opt. Express 29(26) 43766-43777 (2021)

Surface plasmon resonance biosensor based on graphene and grating excitation

Kai Tong, Yunxuan Wang, Fucheng Wang, Jiaru Sun, and Xiaogang Wu
Appl. Opt. 58(7) 1824-1829 (2019)