Fig. 3.

Paper-based biosensors for potential antigen and antibody detection for COVID-19. a Monoplexed and multiplexed paper-based biosensors or lateral flow test strips for the detection of antibodies specific to the viruses. A customized phone application records the results along with the patient data for disease management. Adapted with permission from [102]. b A paper-based biosensor which detects IgG and IgM for COVID-19. Adapted with permission from [103]. c 3D-μPAD and its simple operation for simultaneous detection of three different antibodies for medical diagnosis. Adapted with permission from [107]