Promising near-infrared plasmonic biosensor employed for specific detection of SARS-CoV-2 and its spike glycoprotein

Timely and accurately identification of the novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can greatly contribute to monitoring and controlling the global pandemic. This study gained theoretical insight into a novel phase-modulation plasmonic biosensor working in the near-infrared (NIR) regime, which can be employed for sensitive detection of SARS-CoV-2 and its spike (S) glycoprotein. The proposed plasmonic biosensor was created by integrating two-dimensional (2D) Van der Waals heterostructures, including tellurene and carboxyl-functionalized molybdenum disulfide (MoS2) layers, with transparent indium tin oxide (ITO) film. Excellent biosensing performance can be achieved under the excitation of 1550 nm by optimizing the thickness of ITO film and tellurene-MoS2 heterostructures. For a sensing interface refractive index change as low as 0.0012 RIU (RIU, refractive index unit), the optimized plasmonic configuration of 121 nm ITO film/three-layer tellurene/ten-layer MoS2-COOH can produce the highest detection sensitivity of 8.4069 x 10(4) degree/RIU. More importantly, MoS2-COOH layer can capture angiotensin-converting enzyme II, which is an ideal adsorption site for specifically binding SARS-CoV-2 S glycoprotein. Then, an excellent linear detection range for S glycoprotein and SARS-CoV-2 specimens is similar to 0-301.67 nM and similar to 0-67.8762 nM, respectively. This study thus offers an alternative strategy for rapidly performing novel coronavirus diagnosis in clinical applications.