Quick, sensitive diagnosis of COVID-19 It is essential for early treatment, tracing contacts and reducing viral transmission. However, some people are affected SARS-CoV-2 receive negative-false test results, which can put the risk and health of others. Currently, researchers report on ACS ‘ Nano Letters has developed ultra-absorbent nanofiber swabs that can reduce the number of false negative tests by increasing sample collection and test sensitivity.
Currently, the most sensitive test for COVID-19 involves using a long swab to collect specimens from deep inside the patient’s nose, then using a method called reverse transcriptase-polymerase chain reaction (RT-PCR) to detect SARS-CoV-2 RNA. But if the viral load is low, which can occur early in the period of infection, the swab is thought to be unable to allow enough viruses to be detected.
Jingwei Xie and colleagues want to develop a nanofiber swab that can absorb and release more viruses and other biological specimens, increasing the sensitivity of diagnostic tests.
Researchers used an electrospinning technique to create a 1 cm long cylinder made of lined nanofiber layers, which were coated with a thin layer of gelatin and fastened to a plastic swab rod.
In laboratory tests, shaft nanofiber tubes absorb and release more proteins, cells, bacteria, DNA and viruses from liquids and surfaces instead of cotton or swabs that are commonly used for COVID-19 testing. The team diluted SARS-CoV-2 virus, wiped the liquid sample and tested for viral RNA by RT-PCR. Compared with the other two types of swabs, nanofiber reduced false negative levels and detected SARS-CoV-2 at a concentration 10 times lower.
In addition to allowing for more accurate and sensitive COVID-19 testing, nanofiber swabs have the potential to diagnose other diseases, test for foodborne illness and help the forensic team identify criminal suspects from miniscule biological specimens, researchers said.
References: “Ultra-absorbent Nanofiber Swabs to Improve Collection and Test Sensitivity of SARS-CoV-2 and Other Biological Specimens” January 26, 2021, Nano Letters.
DOI: 10.1021 / acs.nanolett.0c04956