Paper-based test can detect COVID within five minutes

A team led by an Indian-origin scientist  Dipanjan Pan has developed a rapid, ultrasensitive COVID-19 test using a paper-based electrochemical sensor that can detect the presence of the novel coronavirus in less than five minutes. The researchers from the University of Illinois in the US created a graphene-based electrochemical biosensor with an electrical read-out setup to selectively detect the presence of SARS-CoV-2 genetic material

There are two components to this biosensor: A platform to measure an electrical read-out, and probes to detect the presence of viral RNA, according to the research published in the journal ACS Nano. To create the platform, the researchers first coated filter paper with a layer of graphene nanoplatelets to create a conductive film. They then placed a gold electrode with a predefined design on top of the graphene as a contact pad for electrical readout.Both gold and graphene have high sensitivity and conductivity which makes this platform ultrasensitive to detect changes in electrical signals, the researchers noted.

Maha Alafeef, a graduate student at the University of Illinois Grainger College of Engineering, said, "Graphene exhibits unique mechanical and electrochemical properties that make it ideal for the development of sensitive electrochemical sensors." The team tested the performance of this sensor by using coronavirus positive and negative samples. The sensor showed a significant increase in the voltage of positive samples compared to the negative ones and confirmed the presence of viral genetic material in less than five minutes. The researchers noted that this platform has far-reaching applications due to its portability and low cost.