Career Development and Training Program
Individual Project CD007
Collaborating Institution: Texas State University (TSU), San Marcos, TX
Principal Investigator: Shannon Weigum, PhD
Title of the Project: Development of a Paper Microfluidic Platform for Detection of Viral Gastroenteritis
- Robert Atmar, MD – Baylor College of Medicine, Houston, TX
- Gary Beall, PhD – TSU, San Marcos, TX
- Dana Garcia, PhD – TSU, San Marcos, TX
Expected Product: A new platform for detection of clinically-relevant noroviruses that could improve treatment and monitoring of diarrheal illness, as well as assist in the management of outbreaks.
Description: Noroviruses, belonging to the family Caliciviridae, are highly infectious agents that cause acute gastroenteritis in both children and adults worldwide. Norovirus infections are increasingly recognized as a major source of diarrheal illness in hospitals, long-term care facilities, day care centers, and among travelers; yet, access to routine diagnostic tests remains limited. The goal of the current proposal is to develop a rapid diagnostic system for detection of noroviruses that can be employed at the point-of-need. Our approach capitalizes upon recent advances in the fabrication of low-cost microfluidic devices using patterned paper as an instrument-free platform for sophisticated biological assays. These devices are known as microfluidic paper analytical devices (μPADs) or two-dimensional paper networks (2DPNs). In these devices, capillary action draws fluids through the channels eliminating the need for expensive pumps and fluid handling equipment found in traditional microfluidic devices. Furthermore, they are ideal for point-of-need applications and/or resource-poor settings because they use commonly available materials, are inexpensive to fabricate, require minimal sample preparation, provide a simple colorimetric read-out, and are disposable. The following specific aims are proposed for this research; (1) to design a paper-based microfluidic assay for detection of clinically-relevant noroviruses, such as GII.4 which is responsible for the majority of outbreaks in the US; (2) to characterize the assay performance using recombinant viral antigens; and (3) identify clinical utility by testing stool samples from diarrhea patients. Toward these goals we have screened antibodies which bind virus-like particles from multiple GII.4 norovirus strains using a direct ELISA assay. An indirect ELISA procedure will be performed to select the best matched pair of antibodies for capture and detection of noroviruses within the µPAD device. Various cellulose paper materials have been examined and timed fluid flow/delivery of colorimetric reagents have been tested in the prototype device. Synthesis of the magnetic core-shell gold nanoparticle is currently being optimized to generate a monodisperse ~40 nm nanoparticle solution. In the next year, it is expected that a new diagnostic test for norovirus will be established that could impact clinical diagnosis and monitoring of diarrheal illness.