Carbon Nanotube-Induced Enzyme Polymerization for Wearable Multifunctional Biosensors in Sweat Analysis

Wearable sweat sensors have emerged as promising tools for noninvasive health monitoring, yet the low analyte concentrations in sweat compared to blood pose significant challenges for the limit of detection. In this study, we developed a high-sensitivity electrochemical biosensor using carbon nanotube (CNT)-induced enzyme polymerization to detect uric acid and glucose with ultralow detection limits. The CNTs were functionalized via EDC/NHS to achieve covalent enzyme immobilization, enhancing catalytic efficiency, electron transfer, and sensor stability. To enable multifunctional sensing, we integrated glucose and uric acid detection with a pH sensor into a single wearable platform. A radially symmetric microfluidic module was designed through finite element analysis to optimize sweat flow and minimize refresh time, ensuring real-time biomarker tracking. The system also incorporated pH-based signal correction to improve detection accuracy in complex sweat environments. Finally, the sensing performance was validated through on-body sweat collection and analysis from six human volunteers, demonstrating its robustness, reliability, and potential for advancing next-generation personalized healthcare applications. This work provides a framework for designing multifunctional wearable sweat sensors and highlights the role of material and device innovations in overcoming key challenges in this field.