Pencil lead-based wearable sensing platform for noninvasively monitoring sweat biomarkers

Wearable sweat patches that directly interface with the epidermis offer a powerful capacity for recording in-depth healthcare information through noninvasive monitoring of metabolite levels in sweat. However, the current preparative techniques for wearable sweat patches still face multiple challenges, including costly electrode precursors and multistep processes. Here, we report the design and performance of an affordable and easy-to-operate wearable sensing platform for noninvasive on-skin monitoring of sweat metabolic biomarkers (pH, Na⁺, uric acid (UA), and tyrosine (Tyr)) through quick assembly of three-dimensional (3D)-printed microfluidics for sweat capture and commercial pencil lead-based sweat sensors for electrochemical analysis of microvolume sweat. We show the capability of such a wearable sensing platform for in-situ sweat capture and noninvasive monitoring of sweat metabolic biomarkers. We also evaluate its potential application for personalized nutrition through a dietary-controlled study and personalized gout management through a lifestyle-controlled study.