Enhancing Loop-Mediated Isothermal Amplification through Nonpowered Nanoelectric Preconcentration.

The global threat posed by the COVID-19 pandemic has catalyzed the development of point-of-care (POC) molecular diagnostics. While loop-mediated isothermal amplification (LAMP) stands out as a promising technique among FDA-approved methods, it is occasionally susceptible to a high risk of false positives due to nonspecific amplification of a primer dimer. In this work, we report an enhancing LAMP technique in terms of assay sensitivity and reliability through streamlined integration with a nonpowered nanoelectric preconcentration (NPP). The NPP, serving as a sample preparation tool, enriched the virus concentration in samples prior to the subsequent LAMP assay. This enrichment enabled not only to achieve more sensitive assay but also to shorten the assay time for all tested clinical samples by ∼10 min compared to the conventional LAMP. The shortened assay time suppresses the occurrence of nonspecific amplification by not providing the necessary incubation time, effectively suppressing misidentification by false positives. Utilizing this technique, we also developed a prototype of the POC NPP-LAMP kit. This kit offers a streamlined diagnostic process for nontrained individuals, from the sample enrichment, transfer of the enriched sample to LAMP assays, which facilitates on-site/on-demand diagnosis of SARS-CoV-2. This development holds the potential to contribute toward preventing not only the current outbreak but also future occurrences of pandemic viruses.