State of the art overview wearable glucose sensors based on nanosheets

With diabetes emerging as a global health crisis, Wearable Glucose Sensors (WGSs) are drawing significant attention in clinical and healthcare analysis. WGSs can accurately detect the glucose concentration by wearable electrodes and attached signal processors to increase the real-time performance and comfort of patients. Electrodes are the key components of sensors, determining sensing performance in terms of detection and duration. While nanosheet is one of the ideal electrodes due to superior properties in physical and electrochemical fields, including conductivity, specific surface area, porosity, and modification ability, a systematic comparison of their cross-disciplinary applications remains scarce. This review provides a distinctive perspective by offering a comprehensive and critical evaluation of nanosheet-based electrodes for WGSs, bridging the gap between fundamental materials science and wearable sensing performance. In this review, WGSs are divided into four main categories according to nanosheet electrode materials: (i) graphene and graphene analogs, including laser-induced graphene (LIG), graphene sponge (GS), and graphene quantum dots (GQDs) (ii) metallic nanosheets, encompassing MXenes, metal-organic frameworks (MOFs), and bimetallic alloys, (iii) polymer nanosheets such as polyaniline (PANI) and Schiff base polymer (SBP), and (iv) black phosphorus (BP) nanosheet and composite nanosheet. The properties and fabrication method of each material are generally introduced. Moreover, the ideas of materials selection and key points of modification are illustrated by case studies of existing nanosheet-based sensors. Furthermore, this study uniquely discusses the trade-offs between sensitivity, mechanical durability, and biocompatibility for skin-interfaced applications. Finally, the necessary considerations and current challenges of developing nanosheet-based WGSs are concluded, and the prospects are discussed in the end.