Wearable Wireless Patch with Unidirectional Microfluidic Chamber for Enzyme-Free Glucose Monitoring in Sweat

Conventional glucose sensors based on biological enzymes are prone to interference in complex environments, particularly for wearable sweat monitoring. Although synthetic nanozymes exhibit higher stability, they often require highly alkaline conditions to achieve optimal performance, limiting their application in wearable devices. To address this challenge, this study presents a novel enzyme-free wearable wireless patch capable of real time, in situ monitoring of glucose concentrations in sweat. The device employs a microfluidic channel to collect sweat, where solid NaOH is dissolved to create the required alkaline environment. Subsequently, the sweat enters a detection chamber, where two-dimensional nickel-based organic framework nanoflowers modified with gold nanoparticles (Au-NPs/Ni-BDC NFs) serve as the sensing layer, enabling highly sensitive and stable glucose detection. Integrated temperature and pH sensors provide real time calibration to ensure measurement accuracy, while a Tesla valve prevents the backflow of alkaline solution to the skin. A custom-designed smartphone application facilitates real-time analysis of sweat glucose levels during physical activity, by managing signal acquisition, processing, and wireless communication. Through in situ pretreatment of sweat within the microfluidic channel and cooperative operation with a sensor array, this study effectively overcomes key challenges in enzyme-free glucose sensing for wearable devices. The proposed system demonstrates significant potential for future health monitoring, particularly for real-time tracking during exercise and daily activities.