New method for detecting single coronavirus particles

Scientists have developed a new method for identifying particles of a single virus based on changes in the electrical current as they pass through ultra-small pores, an advance that they believe could lead to new rapid COVID-19 tests.
The study, published in the journal ACS Sensors, demonstrated a novel system for identifying individual viral particles using an algorithm trained to detect changes in the current passing through the silicon nanopores.
According to scientists, including those from Osaka University in Japan, the work could lead to rapid and accurate screening tests for diseases like COVID-19 and influenza.
In the new method, the scientists said that a layer of the silicon nitride compound just 50 nanometers (nm) thick added tiny nanopores.
The layer is suspended on a silicon wafer, they said, adding that when a voltage difference is applied to the solution on both sides of the wafer, ions travel through the nanopores in a process called electrophoresis.
According to the study, the movement of ions can be monitored by the current they generate, and when a viral particle enters a nanopore, it blocks the passage of some ions, leading to a transient drop in current.
Each dip reflects the particle’s physical properties, such as volume, surface charge and shape, the scientists said, adding that this measurement can be used to identify the type of virus. Using artificial intelligence (AI), the research team built a trained classification algorithm with signals from known viruses to determine the identity of new samples.
Using artificial intelligence (AI), the research team built a trained classification algorithm with signals from known viruses to determine the identity of new samples.
Scientists said that the computer can discriminate differences in electric current waveforms that cannot be identified by human eyes, which allows for highly accurate classification of viruses.
In addition to the coronavirus, they claimed that the system has been tested with pathogens such as adenovirus, influenza A and influenza B. In addition to the coronavirus, they claimed that the system has been tested with pathogens such as adenovirus, influenza A and influenza B.
“By combining single-particle nanopore detection with artificial intelligence, we were able to achieve highly accurate identification of multiple viral species,” explained senior study author Makusu Tsutsui of Osaka University.
Researchers believe coronaviruses are particularly well suited for this technique as their spiky outer proteins may even allow for separate classification of different strains.
“This work will help with the development of a virus test kit that surpasses conventional viral inspection methods,” said Tomoji Kawai, another co-author of the study.
Compared to other rapid tests such as PCR or antibody-based screens, the researchers said the new method is much faster and requires no expensive reagents.
Compared to other rapid tests such as PCR or antibody-based screens, the researchers said the new method is much faster and requires no expensive reagents.
They believe the new technique could lead to better diagnostic tests for emerging viruses that cause infectious diseases such as COVID-19.