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An extremely fast Covid test: according to a study published today in the Journal of Vacuum Science & Technology B, a new and portable saliva-based COVID-19 testing method detects the virus much faster than any other currently available method.
How fast? Within one second, the authors claim.
The COVID-19 pandemic has made it clear that the world needs technological innovations to detect, treat, and prevent the SARS-CoV-2 virus.
A year and a half into this epidemic, waves of new outbreaks continue to plague many parts of the world.
Fortunately, researchers from the University of Florida and Taiwan’s National Chiao Tung University worked together to come up with a very fast and very sensitive new testing method for COVID-19 biomarkers.
The researchers previously developed ways of detecting biomarkers relevant to the Zika virus, heart attacks, and even spinal fluid leaks. They used this expertise to develop a new sensor system that provides detection within one second, which is far faster than any current COVID-19 detection methods.
Detecting the presence of the virus requires either amplifying the numbers of the biomarker (for COVID-19 detection, this involves copies of viral ribonucleic acid in the common polymerase chain reaction technique), or amplifying the binding signal for a target biomarker.
The group’s new method uses the latter method, amplifying the binding signal for a target biomarker.
“Our biosensor strip is similar to commercially available glucose test strips in shape, with a small microfluidic channel at the tip to introduce our test fluid,” said co-author Minghan Xian of the University of Florida. “Within the microfluidic channel, a few electrodes are exposed to fluid, he said. “One is coated with gold, and COVID-relevant antibodies are attached to the gold surface via a chemical method.”
To measure the antibodies, the researchers connect sensor strips to a circuit board. Then a short electrical test signal gets sent between the gold electrode bonded with COVID antibody, and another auxiliary electrode. This signal is then returned to the circuit board for analysis.
The researchers used commercially available glucose test strips as biofunctionalized cartridges for electrochemical measurements.
“Our sensor system, a circuit board, uses a transistor to amplify the electrical signal, which then gets converted into a number on the screen,” said Xian. “The magnitude of this number depends on the concentration of antigen, the viral protein, present within our test solution.”
Although the system’s sensor strips must be discarded after use, the test circuit board itself is reusable. This can greatly reduce the cost of testing. That means the versatility of this technology goes far beyond detecting COIVD-19.
“By altering the type of antibodies attached to the gold surface, we can repurpose the system to detect other diseases,” said Xian. “The system can serve as a prototype for modularized, inexpensive protein biomarker sensors for expedient real-time feedback within clinical applications, operating rooms, or home use.”
Study: “Fast SARS-COV-2 virus detection using disposable cartridge strips and semiconductor-based biosensor platform“
Authors: Minghan Xian, Hao Luo, Xinyi Xia, Chaker Fares, Patrick H. Carey IV, Chan-Wen Chiu, Fan Ren, Siang-Sin Shan, Yu-Te Liao, Shu-Min Hsu, Josephine F. Esquivel-Upshaw, Chin-Wei Chang, Jenshan Lin, Steven C. Ghivizzani, and Stephen J. Pearton
Published in: Journa of Vacuum Science & Technology B
Publication date: May 18, 2021
Photo: by National Cancer Institute on Unsplash