Researchers at the Korea Basic Science Institute, Korea Research Institute of Chemical Technology, and collaborators have published an article on the development of graphene-based test for SARS-CoV-2, the virus causing COVID-19, from nasopharyngeal swabs. They have determined it can detect SARS-CoV-2 in clinical samples at a concentration of 242 copies per mL. and greater, a significant achievement.
Current diagnostic tests for COVID-19 utilize RT-PCR, amplifying the SARS-CoV-2 RNA from patient samples so tiny amounts of virus can be detected. It takes at least 3 hours, including methods for RNA preparation. The researchers who initiated this new study wanted to develop a faster test directly from patient swabs, without sample preparation steps.
The test is based on field-effect transistor incorporating a sheet of graphene. The surface of the graphene is coated with antibodies specific to SARS-CoV-2. When SARS-CoV-2 or viral protein are added, the sensor detects a change in electrical current.
Without specific sample preparation, the sensor could discriminate between healthy and sick patients. The researchers note that the test was about 2-4 times less sensitive than RT-PCR, but that different materials may be explored to improve signal-to-noise ratio.
The publication in journal ACS NANO: Rapid Detection of COVID-19 Causative Virus (SARS-CoV-2) in Human Nasopharyngeal Swab Specimens Using Field-Effect Transistor-Based Biosensor