Graphene-Based Field-Effect Transistor for Ultrasensitive Immunosensing of SARS-CoV‑2 Spike S1 Antigen

• Published in: ACS applied bio materials Vol. 5; no. 7; pp. 3563 - 3572
• Main Authors: Shahdeo, Deepshikha, Chauhan, Neha, Majumdar, Aniket, Ghosh, Arindam, Gandhi, Sonu
• Format: Journal Article
• Language: English
• Published: American Chemical Society 18.07.2022
• Subjects: SARS-CoV-2; MERS-CoV antigen; field-effect transistor; graphene; SARS-CoV-2 Spike S1 antigen
• ISSN: 2576-6422; 2576-6422
• DOI: 10.1021/acsabm.2c00503

Coronavirus disease (COVID-19) is an infectious disease that has posed a global health challenge caused by the SARS-CoV-2 virus. Early management and diagnosis of SARS-CoV-2 are crucial for the timely treatment, traceability, and reduction of viral spread. We have developed a rapid method using a Graphene-based Field-Effect Transistor (Gr-FET) for the ultrasensitive detection of SARS-CoV-2 Spike S1 antigen (S1-Ag). The in-house developed antispike S1 antibody (S1-Ab) was covalently immobilized on the surface of a carboxy functionalized graphene channel using carbodiimide chemistry. Ultraviolet–visible spectroscopy, Fourier-Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), Optical Microscopy, Raman Spectroscopy, Scanning Electron Microscopy (SEM), Enzyme-Linked Immunosorbent Assays (ELISA), and device stability studies were conducted to characterize the bioconjugation and fabrication process of Gr-FET. In addition, the electrical response of the device was evaluated by monitoring the change in resistance caused by Ag–Ab interaction in real time. For S1-Ag, our Gr-FET devices were tested in the range of 1 fM to 1 μM with a limit of detection of 10 fM in the standard buffer. The fabricated devices are highly sensitive, specific, and capable of detecting low levels of S1-Ag.