A novel flow through assay and smartphone application based prototype for point-of-care diagnosis of tuberculosis.

Affordable point-of-care test sensors with automated result recording are essential for reducing undetected tuberculosis cases in remote, resource-limited areas. Therefore, this study addresses this need with three key aims. First, we aimed to lower the costs of a patented flow-through assay (Kit and method: WO2016/024116A1) by developing an in-house method for producing antibody-coated gold nanoparticles (anti-IgG-AuNPs). These anti-IgG-AuNPs demonstrated specific binding with performance comparable to existing antibody-capped gold nanoparticles. The second aim was to transform the flow-through assay into a multi-disease screening tool by incorporating multiple antigen test spots. A newly designed wax-printed background allows for simultaneous testing of up to five antigens, delivering results within 15 min at the point-of-care, while also reducing assay costs by 70 %. Lastly, we developed a smartphone application (RAP-TBS) to provide quantitative analysis of the flow-through assay results. This user-friendly app requires no additional hardware and addresses the limitations of subjective visual interpretation.