Paper-based electrochemical sensors: New coronavirus detected within 5 minutes

, Dec. 9 (Xinhua Zhang Jiaxin) As the outbreak of neo-crown pneumonia continues to spread around the world, testing remains a key strategy to track and contain the virus. Maha Arafif, a graduate student in bioengineering at the University of Illinois' Granger School of Engineering, has developed a fast, ultra-sensitive detection method that uses a paper-based electrochemical sensor to detect the presence of the virus in less than five minutes, science daily reported.
main advantages of using graphene-like two-dimensional nanomaterials to manufacture biosensors are high sensitivity, low production costs and fast detection cycle. The team used electrochemical biosensors developed by graphene, with electronic reading devices, to selectively detect the presence of new coronavirus RNA. The sensor has two components: a platform for measuring electronic readings and a probe for detecting viral RNA.
researchers first applied a layer of graphene nano-sheets to the filter paper to form a conductive, and then placed a gold electrode with a predetermined design on the graphene as a point of contact for electronic reading. Both gold and graphene are highly sensitive and conductive, making the platform very sensitive to detecting changes in electrical signals.
the current new coronavirus RNA test can screen for the presence of the N gene (nuclear shell phosphorus protein) in the new coronavirus. In this study, the team designed an anthotic oligonucleotide (ASOS) probe to target two regions of the N gene. In the case of a genetic mutation in one region, targeting two regions ensures the reliability of the sensor. In addition, gold nanoparticles (AuNP) are covered with these single-stranded nucleic acids (ssDNA), which shows the ultra-sensitivity of the sensing probe.
team tested the sensor's performance using samples that tested positive and negative for the new coronavirus. Compared to the negative sample, the sensor showed a significant increase in the voltage of the positive sample and confirmed the presence of viral RNA in less than 5 minutes. In addition, the sensor is able to distinguish between viral RNA loads in these samples. Viral load is an important quantitative measure of infection progress and a challenge to measure using existing diagnostic methods.
portability and low cost make the sensor widely possible. It is integrated with microcontrollers and LED screens, or connected to smartphones via Bluetooth or WiFi, and can be used in doctor's offices or even at home medical points. In addition to the new coronavirus, the team believes the system is also suitable for detecting viruses from many different diseases.