Lab-on-paper for molecular testing with USB-powered isothermal amplification and fluidic control.

The global healthcare market increasingly demands affordable molecular diagnostics for field testing. To address this need, we introduce a lab-on-paper (LOP) platform that integrates isothermal amplification with a specially designed paper strip for molecular testing through an automated microfluidics process. The LOP system is engineered for rapid, cost-effective, and highly sensitive detection, using USB-powered thermal management and a wax valve mechanism. This innovative platform provides an accessible solution for the rapid and accurate detection of various microorganisms, proving particularly advantageous for point-of-care testing in resource-limited environments. Experiments conducted in this study demonstrated the efficacy of the LOP platform in the colorimetric detection of foodborne pathogens. It reliably detected Vibrio vulnificus at concentrations as low as 120 CFU/mL and Salmonella Typhimurium at 60 CFU/mL, with results observable to the naked eye. The entire process, encompassing amplification and detection, was completed within 30 min, underscoring the system's rapid diagnostic capability. Furthermore, with an assay cost of 5.2 USD per test, the platform offers a highly cost-effective solution for molecular diagnostics, particularly in resource-limited settings. The LOP platform's portability, ease of use, and affordability make it a promising alternative for various diagnostic applications, including infectious disease monitoring and ensuring food safety.