Development of a Novel Paper-Based Flu Test for Improved Diagnosis at the Point of Care

Abstract

The development of paper-based diagnostics has surged in recent years, due to the suitability of these tests for use at the point of care. Paper-based diagnostics offer the ability to perform relatively sophisticated chemical processing, but in an automated device that is low in cost, generates a result in a matter of minutes, and can be operated by untrained users in clinics and homes around the world. Influenza infection, or the flu, is one illness that stands to benefit greatly from the improved point-of-care testing afforded by paper-based diagnostics. This commonly occurring infection results in millions of illnesses and thousands of deaths in the U.S. each year, many of which could be prevented or mitigated by timely and effective diagnosis and disease management. Improved point-of-care flu testing could also help reduce inefficient and wasteful healthcare spending, as well as the economic burden of flu due to lost productivity. To this end, we have developed a novel paper-based assay for influenza, based on the detection of the surface protein hemagglutinin. This assay was made possible by the use of novel, recombinant affinity proteins for influenza hemagglutinin, developed by collaborators of the project. Since these “flu binders” represent a significant departure from the mainstay of IgG capture molecules for traditional paper-based assays, the use of these affinity proteins required the in-depth study of protein adsorption to paper and the development of novel immobilization methods. Using the combination of the recombinant flu binders and the immobilization and assay strategies developed herein, we demonstrated a novel paper-based assay for influenza detection that is more sensitive than a traditional lateral flow immunoassay. Additionally, since this assay targets the hemagglutinin protein of influenza, it allows for the possibility for influenza subtyping, which is not available for any influenza rapid diagnostic test on the market. Overall, this work represents a significant development towards improved influenza diagnosis and disease management at the point of care.