Researchers have invented a graphene-based ultrasensitive device that can detect minute traces of the Japanese encephalitis virus (JEV) and the Avian influenza type A virus (AIV) in patients1.
This device, they say, can be converted into a real-time biosensor for the rapid and early diagnosis of JEV and AIV, as well as other infectious diseases.
A specific species of Culex mosquito transmits JEV from pigs and wading birds to humans. AIV jumps from chicken to humans. Existing methods for detecting these viruses are complex and time consuming.
To find a simple, rapid test, scientists from the DBT-National Institute of Animal Biotechnology in Hyderabad and the Indian Institute of Science in Bangalore, both in India, made the device by depositing modified graphene on a silicon-based substrate. They then attached JEV and AIV antibodies separately to the graphene-coated substrate. These antibodies are known to bind to and neutralise viral proteins such as JEV and AIV antigens in infected humans.
The researchers probed the efficiency of the device by exposing it to solutions containing ultra-low concentrations of JEV and AIV antigens.
During such exposure, the JEV and AIV antibodies on the device bound to the antigens, causing a change in its resistance – an electrical signal that helps detect the presence and measure the concentrations of the viruses.
Its resistance, the researchers found, increased with increasing antigen concentrations, enabling it to detect the viruses in a few seconds. They were able to record the response within five minutes.
1. Roberts, A. et al. Graphene functionalized field‑effect transistors for ultrasensitive detection of Japanese encephalitis and Avian influenza virus. Sci. Rep. 10, 14546 (2020)