Label-free plasmonic-based biosensing using a gold nanohole array chip coated with a wafer-scale deposited WS₂ monolayer

• Main Authors: Kang, Lixing, Zhang, Yan, Gong, Qian, Das, Chandreyee Manas, Shao, Huilin, Poenar, Daniel Puiu, Coquet, Philippe, Yong, Ken-Tye
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Electrical and electronic engineering; Plasmonic Biosensor; Nanohole Array
• Online Access: https://hdl.handle.net/10356/166436
• Institution: Nanyang Technological University

This paper reports the fabrication, testing and obtained performance of a plasmonic sensor employing a gold (Au) nanohole array chip coated with tungsten disulphide (WS2), which is then functionalized for the detection of protein-protein interactions. A key novelty is that the WS2 was deposited as a monoatomic layer using a wafer-scale synthesis method that successfully provided a film of both high quality and uniform thickness. The deposited WS2 film was transferred onto a Au nanohole array chip using a novel method and was subsequently functionalized with biotin. The final sensor was tested and it demonstrated efficient real-time and label-free plasmonic detection of biotin-streptavidin coupling. Specifically, compared to a standard (i.e. uncoated) Au nanohole-based sensor, our WS2-coated Au nanohole array boosted the spectral shift of the resonance wavelength by ∼190%, resulting in a 7.64-fold improvement of the limit of detection (LOD).