Enhancing Rapid Disease Detection: Capillary Flow Microfluidics for Point-of-Care Diagnostics

Point-of-care (POC) technologies have been a useful tool in medical and environmental diagnostics for decades with the handheld glucometer as a leading example. The COVID-19 pandemic further pushed POC technologies to the forefront of many people’s thinking. In addition, the pandemic has expanded the opportunities for using these tools as important tools outside of just human health applications. However, a major conundrum in many POC diagnostics has been the tradeoff between assay performance (sensitivity, specificity, LOD, etc) and ease of use. Microfluidic Paper-based Analytical Devices (mPADs) have received significant attention as a tool to address current shortcomings in both medical and environmental diagnostics because they are inexpensive, easy to use, and can perform a wide range of chemical and biochemical assays. mPADs are normally made from porous hydrophilic materials patterned with hydrophobic materials to create flow barriers to direct flow from a sample inlet through sample pretreatment zones to a detection zone. Furthermore, functional elements like electrodes can be easily integrated, improving functionality, sensitivity, and selectivity. Despite their advantages, mPADs are frequently limited to long analysis times (10s of minutes) due to slow capillary flow and poor limits of detection due to an inability to amplify signal. Our group has recently reported capillary-flow driven microfluidic devices that use channels formed using laser patterning in polyester films and double-sided adhesive combined with paper-based pumps and reagent storage systems to enhance the performance of mPADs. We refer to these devices as fast-flow paper-based microfluidic devices. This talk will focus on both traditional mPADs as well as newer fast-flow devices for point-of-need diagnostics with applications in both clinical and environmental diagnostics. The talk will start with the fundamental underpinnings and conclude with how this is moving from bench to bedside.