Recent advances in the fabrication strategies of paper-based microfluidic devices for rapid detection of bacteria and viruses

The early detection of pathogens plays a significant role in reducing fatalities and improving prognosis. Laboratory tests such as the cell culture, polymerase chain reaction, and immunoassays are performed for the identification of pathogens; however, these are time-consuming and require trained personnel, limiting their prompt use at the point of need. Several microfluidic devices have been developed for point-of-care testing (POCT), including microfluidic paper-based analytical devices (µPADs). Paper, as a material, holds great promise for POCT owing to its advantages such as low cost, easy fabrication, easy disposal, and equipment-free operation by capillary action, which coincides with the requirements for an ideal rapid test. Considering this, we summarize major µPAD fabrication techniques as well as the fluid controlling strategies published to date. The development of various fabrication techniques is important for finding appropriate mass-production methods, and fluid control determines the complexity of the analysis. We also emphasize on recent bacterial and viral detection strategies from recent publications. Finally, this review discusses the challenges of developing an integrated device that can provide quantitative results to further improve the performance of bacterial and viral detection.