Abstract
The noninvasive glucose sensors with comprehensive functional capabilities can enable wearable glucose monitoring in sweat with high sensitivity and minimal risk. However, the limited stability of natural enzymes, along with interference from electro-oxidizable species, continues to pose significant challenges for their long-term application. Herein, an integrated wearable system is presented for nonenzymatic glucose monitoring in sweat at the point of care. This system integrates a flexible microfluidic glucose sensor patch for sweat sampling and measurement, using Pt nanoparticles (Pt-NPs) confined within phthalocyanine-based conductive metal-organic frameworks (Pc-MOFs) as electrode materials, and a flexible printed circuit board for signal/analysis and wireless communication. The microfluidic sensor patch based on Pc-MOFs confined Pt-NPs exhibits significantly improved nonenzymatic glucose sensing performances. This is attributed to the ultrasmall size of Pt-NPs and the confinement effect within the Pc-MOF channels, which regulates the glucose adsorption intensity and increases the electrocatalytic activity to glucose oxidation. During the continuous monitoring process, the glucose concentration is calibrated in sweat by accounting for fluctuations in pH and temperature, and evaluated the performance of the wearable device in monitoring sweat glucose levels in human subjects over a 12-h period, achieving data as accurate as that obtained using high-performance liquid chromatography.