Electrical probing of COVID-19 spike protein receptor binding domain via a graphene field-effect transistor

TL;DR

This paper presents a graphene field-effect transistor (Gr-FET) based immunosensor capable of rapid, sensitive, and label-free detection of COVID-19 spike protein, offering a promising tool for early diagnosis and antibody screening.

Contribution

The study introduces a highly sensitive, rapid, and label-free Gr-FET immunosensor for COVID-19 detection, combining graphene technology with antibody-antigen specificity.

Findings

Detects COVID-19 spike protein at 0.2 pM limit of detection

Identifies the protein in about 2 minutes

Screens high-affinity antibodies down to 0.1 pM

Abstract

Here, in an effort towards facile and fast screening/diagnosis of novel coronavirus disease 2019 (COVID-19), we combined the unprecedently sensitive graphene field-effect transistor (Gr-FET) with highly selective antibody-antigen interaction to develop a coronavirus immunosensor. The Gr-FET immunosensors can rapidly identify (about 2 mins) and accurately capture the COVID-19 spike protein S1 (which contains a receptor binding domain, RBD) at a limit of detection down to 0.2 pM, in a real-time and label-free manner. Further results ensure that the Gr-FET immunosensors can be promisingly applied to screen for high-affinity antibodies (with binding constant up to 2*10^11 M^-1 against the RBD) at concentrations down to 0.1 pM. Thus, our developed electrical Gr-FET immunosensors provide an appealing alternative to address the early screening/diagnosis as well as the analysis and rational design of neutralizing-antibody locking methods of this ongoing public health crisis.