Synergistic Dual-Electron Transfer in MXene Microneedles for Ultrasensitive Continuous Glucose Monitoring

Abnormal glycemic management in diabetic patients may lead to severe acute consequences such as hypoglycemia and hyperosmolar coma. Although continuous glucose monitoring (CGM) allows timely detection of dysglycemia, conventional electrochemical sensors are often limited by narrow detection ranges and insufficient sensitivity for reliable long-term in vivo use. To overcome these limitations, we developed glucose oxidase (GOx)-functionalized Ti 3 C 2 Tx MXene-Au microneedles (GTA-MNs) for real-time interstitial glucose sensing, achieving nanomolar sensitivity and stable operation for over 10 days. Upon skin insertion and contact with glucose, the Ti 3 C 2 Tx MXene nanocomposite activates a dual electron-transfer pathway. It simultaneously facilitates direct electron transfer through the enzymatic FAD/FADH 2 center of GOx and catalyzes the indirect oxidation of enzymatically generated H 2 O 2 . This synergistic mechanism enables a broad detection range from 10 nM to 50 mM and an ultralow detection limit of 1.444 nM. A support vector regression calibration model was implemented to dynamically align sensor signals with blood glucose levels, thereby compensating for physiological lag. Comprehensive in vitro and in vivo validations confirmed the system's high accuracy, stability, and biocompatibility. Furthermore, we engineered a user-friendly home-diagnostic system that wirelessly pairs the wearable patch with a smartphone, enabling CGM in freely moving subjects to support personalized diabetes management.