Do you have a cough, sore throat, or congestion? Any number of respiratory viruses can be to blame. Conventional tests can identify specific probable causes by relying on chemical reactions, but some researchers want to trade chemical reactions for electrical changes sensed by nanomaterials. . Today, scientists report using single-atom-thick nanomaterials to build a device that can simultaneously detect the presence of the virus that causes COVID-19 and the flu. This is done at a much lower level and much faster than any of the traditional tests.
The researchers plan to present their results at the Spring Meeting of the American Chemical Society (ACS). ACS Spring 2023 will feature over 10,000 of his presentations on a wide range of scientific topics in a hybrid virtual and in-person meeting taking place March 26-30.
The symptoms of both influenza and COVID-19 overlap so much that it becomes difficult to distinguish between them, said Dr. Deji Akinwande, who is presenting the study at the conference.
“When both of these viruses are circulating together, as was the case at the beginning of this winter, having a sensor that can detect COVID, flu, or none of the above, or both at the same time, would be very helpful.” he says.
Akinwande of the University of Texas at Austin says the device he and his colleagues are developing could be modified to test for other infectious diseases.
A group, including Dr. Dmitry Kireev, a postdoc in Akinwande’s lab, used graphene, a single layer of carbon atoms arranged in a hexagonal lattice pattern, to build COVID-19 and influenza sensors. Its extreme thinness makes graphene highly sensitive to electrical changes in its environment. Akinwande and others see great potential in using it and other similar nanomaterials to create sensors for a variety of applications.
“These ultrathin nanomaterials generally hold the record for the highest sensitivity, down to the detection of single atoms, and basically anything you need to sense, whether it’s bacteria or viruses. We can improve our ability to detect very low amounts of , either in gas or in blood,” says Akinwande.
Previously, his group reported designing graphene-based temporary tattoos that could monitor blood pressure. The tattoo consists of a pair of sensors placed along the arteries of the arm. Half of each pair transmits the current detected by its partner. This signal is used to determine blood flow.
To build an infection sensor, researchers needed to make graphene respond to the presence of viral proteins. To do so, they turned to the immune system, which produces antibodies that are finely tuned to recognize and trap specific pathogens. The researchers linked graphene to his antibodies against SARS-CoV-2, the virus that causes COVID-19, and against the influenza virus. When a sample from an infected person is placed on the sensor, these antibodies bind to target proteins and induce a change in electrical current.
Researchers didn’t have the safety facilities needed to use a full, active flu or SARS-CoV-2 virus to test about a square inch of sensor. Instead, they used proteins from these viruses that are delivered in a liquid that mimics saliva. Their results showed that the sensor could not only detect the presence of proteins, but even when they were present in very low amounts. This sensitivity suggests that the sensor could be used to detect the much sparse viral particles found in exhaled breath, Akinwande said.
The sensor also worked quickly, returning results within about 10 seconds of dropping the sample. By comparison, his traditional COVID-19 test can take minutes to hours, depending on the type, and his dual COVID-flu test, recently approved by the U.S. Food and Drug Administration, takes about It takes 30 minutes.
Akinwande and his group are working to further improve performance, including expanding the types of viruses that can be detected. With funding from the National Science Foundation, they are developing sensors designed to test SARS-CoV-2 variants such as Omicron and Delta. They’re currently focused on designing two variants, but they say the test could be adapted to identify more simultaneously.
Original: Is it COVID-19 or the flu? New sensor tells us in 10 seconds
Than: University of Texas at Austin | American Chemical Society
