No need for uncomfortable blood tests or nose swabs since new low-cost skin patch test identifies COVID-19 antibodies in minutes

Tokyo: A unique compact patch created by Japanese researchers can detect the presence of Covid antibodies non-invasively in three minutes.
The University of Tokyo researchers focused on the interstitial fluid (ISF), which is found in the epidermis and dermis layers of human skin, to identify anti-Covid IgM/IgG antibodies.
The findings, published in the journal Scientific Reports, demonstrated that the novel antibody-based technique aids in the speedy and precise identification of SARS-CoV-2.

To present, the most common Covid detection procedure is swabbing the nose and mouth for samples.

However, the applicability of this technology is limited due to its long detection time (4-6 hours), expensive cost, and need for specialised equipment and medical professionals, especially in resource-poor nations.

The detection of SARS-CoV-2-specific antibodies is an alternative and supplementary approach for confirming Covid-19 infection.

In several countries, testing strips based on gold nanoparticles are now widely used for point-of-care testing. They offer sensitive and consistent findings in 10-20 minutes, but blood samples must be taken by finger prick using a lancing instrument.

This is unpleasant and raises the risk of infection or cross-contamination, and the used kit components may provide a biohazard risk.

“We investigated the possibility of sampling and evaluating the ISF to design a minimally invasive detection assay that would overcome these limitations.” Although antibody levels in the ISF are around 15-25% of those in blood, it was nevertheless possible to identify anti-SARS-CoV-2 IgM/IgG antibodies and that the ISF might operate as a direct alternative for blood sample,” stated lead author Leilei Bao from the varsity’s Institute of Industrial Science.

After proving that ISF could be used for antibody detection, the researchers devised a novel method for sampling and testing the ISF.

“First, we created biodegradable porous polylactic acid microneedles that extract ISF from human skin.”

“We then built a paper-based immunoassay biosensor to detect SARS-CoV-2-specific antibodies,” senior scientist Beomjoon Kim explained.

The lab testing revealed that by combining these two features, the tiny patch could detect antibodies on-site in 3 minutes, according to Kim.

This innovative detection technology has significant potential for quick screening of Covid-19 and many other infectious illnesses while remaining safe and acceptable to patients. According to the scientists, it has potential for usage in many nations regardless of affluence, which is a fundamental goal for global infectious disease management.