Prototype graphene biosensor detects coronavirus in less than a minute

21 Apr 2020

Image: © Marco Taliani/

Researchers have developed a biosensor that can detect coronavirus in less than a minute, but still needs some improvements.

A global effort is underway to roll out coronavirus testing kits as fast as possible to better control the ongoing pandemic. Now, a team in South Korea has posted a study to ACS Nano reporting the development of a biosensor test that can detect Covid-19 in less than a minute.

The biosensor can detect the virus from swabs taken from the nasopharynx, an area at the back of the nasal cavity that connects to the pharynx.

Most tests developed for the virus so far rely on a technique called real-time reverse transcription polymerase chain reaction (RT-PCR). This amplifies coronavirus RNA from patient swabs so that tiny amounts can be detected.

This method typically takes at least three hours, but the South Korean team, which included Edmond Changkyun Park and Seung Il Kim, developed a new test based on a field-effect transistor made from a sheet of graphene with high electronic conductivity.

Still needs improvement

When either purified spike protein or cultured coronavirus was added to the graphene sensor, it binded to an antibody, resulting in a change in the electrical current.

The team then tested the technique on nasopharyngeal swabs collected from patients with Covid-19 as well as healthy controls. Importantly for the study’s findings, the sensor was able to determine which samples came from healthy or sick people.

The research team reported that its new test, while extremely fast, was between two and four times less sensitive than the established RT-PCR technique. However, it’s hoped that using different materials could improve the signal-to-noise ratio and make it just as accurate.

It follows another solution proposed by a team coordinated by the Catalan Institute of Nanoscience and Nanotechnology in Spain, which can identify minute traces of the coronavirus from someone’s saliva more reliably than some existing test kits. The rapid, non-invasive optical biosensor was originally created to look for bacterial infections or cancer biomarkers.

Colm Gorey was a senior journalist with Silicon Republic