Application of microfluidic paper-based analytical device (μPAD) to detect COVID-19 in energy deprived countries

Coronavirus disease (COVID-19) has spread all across the world. Low- and medium-income countries are more affected economically and socially compared to developed countries due to the lack of a rapid, robust, and affordable testing infrastructure. Furthermore, the high cost of real-time polymerase chain reaction (PCR) system, sophisticated user-handling procedure, and high expense of the conventional clinical tests are the root causes of the less accessibility of the testing systems to the users. In this study, a COVID-19 Point-of-Care (POC) ecosystem model is proposed for the low- and medium-income countries (or energy deprived countries) that will facilitate the technological development with locally available fabrication components. In addition, the nontechnological development phases have also been discussed, which encompasses the collaboration among academia, local as well as government bodies, and entrepreneurial ventures. In addition, a hypothetical design of a microfluidic paper-based analytical (μPADs) POC platform is proposed to detect COVID-19 analyte using unprocessed patient-derived saliva, which is a miniaturized form-factor of conventional real-time polymerase chain reaction (PCR) technique. The device contains four major reaction zones, which are sample zone, buffer zone, loop-mediated isothermal amplification (LAMP) Master Mix zone, Ethylenediamine tetraacetic acid (EDTA) zone, and sensor zone. To obtain quicker test results and easier operation, a handheld image acquisition technique is introduced in this study. It is hypothesized that in a remote setting, the proposed design could be used as an initial guideline to develop a POC COVID-19 testing system, which may be simple, easy-to-use, and cost-effective.