A Wearable Enzymatic Uric Acid Sensor on Microfluidics-on-Fabrics with Octadecane (C18) Modification

This study introduces a technology for creating microfluidic devices on garments and an octadecane (C18) modification of the fabric-based microfluidics, representing a novel wearable chemical sensing platform. Integrating microfluidics directly into garments eliminates the need for wearing additional sweat-sensing devices but provides natural comfort, minimal risk of allergies, and capillary actions to drive sweat flows. The C18 modification of the detection zones significantly improved the functionality of fabric-based microfluidics, particularly by enabling efficient and robust enzyme capture for enzymatic assays to analyze sweat metabolites. Our findings demonstrated that the enzyme remained strongly in the detection zone, with minimal loss, even under rigorous continuous flow washing conditions, which is critical because enzyme loss by sweat flow will keep compromising the analytical performance. Moreover, the C18 chemically introduced could retain uricase's activity stably during storage for weeks, indicating promises for mass production and storage of such wearable sensors. Next, a microfluidic-on-hospital gown was developed with immobilized uricase to quantify sweat uric acid levels of a wearer, which yielded accurate results validated by an LC-MS method. Overall, this research represents a significant advancement in wearable microfluidics for enzymatic molecular sensing in sweat.