Development, optimization, and validation of quantitative lateral flow assays for accessible, at-home biomarker monitoring

Abstract

Many chronic autoimmune disorders, like Rheumatoid arthritis and psoriasis, are characterized by painful joint inflammation and extreme fatigue. Patient outcomes are significantly improved by early treatment interventions, which can be enabled through information from continuous monitoring and early detection. The current standard for diagnosis and monitoring of these diseases is laboratory-based testing for the quantification of specific biomarkers. Frequent laboratory blood tests are not feasible for all patients or universally accessible, so a low-cost, point-of-care monitoring solution could improve the monitoring of autoimmune disorders and even provide quantitative metrics of treatment efficacy. The field of paper microfluidics has become a significant source of new tools that expand healthcare accessibility, particularly when designed to be robust in various environments. Innovations in this field have included the use of lateral flow assays and freeze-dried reagents to create portable and accurate testing devices. Here, we present the development of two quantitative sensing techniques for sandwich lateral flow immunoassays, which enable sensitivity to analytes present in two different concentration regimes (one being 1 million times more dilute than the other). The results indicate the utility and readiness of two immunoassays for translation into a paper-based, multiplexed, at-home biomarker monitoring platform.