Evaluation of Paper-based Loop-Mediated Isothermal Amplification

Paper-based loop-mediated isothermal amplification (LAMP) platforms have garnered increasing attention as an alternative to conventional liquid-phase systems, owing to their inherent portability, low-cost fabrication, and user-friendly operation. However, the reaction of paper-based LAMP can be slower than that of liquid-based LAMP. Enhancing the reaction rate in these devices requires a multidisciplinary understanding of heat transfer, diffusion in porous substrates, and nonspecific interaction of reactants with the paper. In this study, heat transfer within both systems is modeled numerically, and effective diffusion within the paper is discussed. Additionally, we demonstrate that pre-treating the paper with bovine serum albumin (BSA) effectively blocks nonspecific binding sites, resulting in an acceleration of amplification of the synthetic gene of the orf7ab of SARS-CoV-2 (NC 045512.2) by approximately 7 minutes. This work presents a quantitative framework for evaluating amplification efficiency in paper-based nucleic acid diagnostics and introduces a straightforward, low-cost strategy for enhancing their performance.