Wearable and Multimodal Electrochemical Hydrogel Sensor for Real-Time Non-Invasive Sweat Glucose Monitoring

Noninvasive sweat glucose monitoring is a promising strategy for real-time health management. In this study, we developed a flexible electrochemical sensor platform based on gold nanorods@polylysine-glucose oxidase (AuNRs@PLL-GOx) composite hydrogel, which enables noninvasive, highly sensitive, and multimode detection of sweat glucose. The polylysine (PLL) interfacial layer provides abundant amino groups for glucose oxidase (GOx) immobilization, improves the dispersion of gold nanorods (AuNRs) within the hydrogel matrix, and facilitates interfacial charge transport by maintaining close contact between GOx and the conductive AuNRs network. These effects improve the electron-transfer efficiency and analytical performance of the hydrogel sensor. Furthermore, the platform integrates differential pulse voltammetry (DPV), cyclic voltammetry (CV), and chronoamperometry (i-t) within a single hydrogel system for sweat glucose monitoring. Benefiting from synergistic and multitechnique detection, the sensor demonstrated excellent analytical performance, including wide detection range (up to 160 μM), low detection limit (3.71 μM), and strong anti-interference capability. These results indicate that this hydrogel-based platform is well suited for future wearable biosensors and smart healthcare systems.