A rapid COVID-19 diagnostic device integrating porous microneedles and the paper-based immunoassay biosensor

New coronavirus, SARS-CoV-2, named as COVID-19 was identified and caused the global pandemic in 2020. Recent challenging issues include providing users with non-invasive and easy-to-use diagnostic devices and identifying the infected to prevent the spread of COVID-19 as quick as possible. In this study, a new COVID-19 diagnostic device that integrates porous microneedles (MNs) with a paper-based immunoassay biosensor was developed for the rapid antibody detection. The biodegradable porous MNs made of polylactic acid (PLA) were fabricated and used to extract the interstitial fluid (ISF) in the human skin by capillary effect. The extracted ISF was flowed into the immunoassay biosensor, which results in the detection of SARS-CoV-2 antibodies on site. From In vitro tests, the result demonstrated that human anti-SARS-CoV-2 IgM and IgG could be detected within 2 min. It is expected that COVID-19 can be diagnosed fast and painlessly owing to the porous MNs as well as a paper sensor with the short flow distance between MNs and a sensor. Besides COVID-19, the proposed device has great potential in the fast screening of various kinds of infectious diseases as an effective complementary method with other diagnostic tests.