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

Abstract

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.

Recent advances of nanotechnology in COVID 19: A critical review and future perspective

“…Notably, immobilization of SARS-CoV-2 spike S1 antibody (S1-Ab) as a sensing element onto the surface of the G-FET sensor has superior S1-Ag binding potentiality. Furthermore, sensitivity and selectivity of the G-FET sensor against SARS-CoV 2 S1-Ag were found to be superior with LOD of 10 fM [120] .…”

State-of-the-Art Smart and Intelligent Nanobiosensors for SARS-CoV-2 Diagnosis

“…The FET-based biosensing platform was developed using a graphene channel conjugated to the spike protein S1 antigen of SARS-CoV-2, and FET was dipped in phosphate-buffer saline. Moreover, the FET sensor determined the spike protein of SARS-CoV-2 with a detection limit (LOD) of 1fg/ML [ 1 , 103 ]. Graphene not only has an essential role in dealing with the current virus, but also provides a technical instrument for detecting, controlling, and protecting against SARS-CoV-2 and forthcoming viral infections.…”

Ultrasensitive and amplification-free detection of SARS-CoV-2 RNA using an electrochemical biosensor powered by CRISPR/Cas13a

“…Electrochemical biosensing platforms have piqued the interest of scientists in diagnostics [9] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , due to their rapid response, high sensitivity and specificity, cost-effectiveness, simplicity, and miniaturization capability. However, accuracy has always been one of the critical challenges in such biosensing platforms.…”