Au nanoparticles anchored carbonized ZIF-8 for enabling real-time and noninvasive glucose monitoring in sweat

Wearable sensors can easily enable real-time and noninvasive glucose (Glu) monitoring, providing vital information for effectively preventing various complications caused by high glucose level. Here, a wearable sensor based on nanozyme-catalyzed cascade reactions is designed for Glu monitoring in sweat. Au nanoparticles (AuNPs) are anchored to the carbonated zeolitic imidazolate framework-8 (ZIF-8-C), endowing the sensor with Glu oxidase (GOx)-like and peroxidase (POD)-like activity. A flexible screen-printed carbon electrode (SPCE) is decorated with the resultant AuNPs@ZIF-8-C, which is further modified with biocompatible and swellable calcium alginate (CA) gels for the preparation of the wearable Glu sensor. The linear range for Glu detection is 10∼300 μM with a limit of detection (LOD) of 4.99 μM, which covers the physiological Glu concentration range in human sweat (10-200 μM). The developed wearable Glu sensor can fit well with the skin tissues due to the flexibility of the SPCE, and thus it can be successfully applied in real-time and noninvasive monitoring of Glu in human sweat. Additionally, the wearable Glu sensor exhibits high antibacterial activity resulted from the generated hydroxyl radicals (·OH), enabling long-term Glu monitoring in sweat.