Non-Enzymatic Sweat-Based Glucose Sensors: Progress, Difficulties, and Prospects

Abstract

Effective diabetes therapy requires continuous glucose monitoring (CGM), yet existing blood-based measurement techniques are invasive and pose discomfort during prolonged use. Sweat's non-invasive collection, real-time secretion and compatibility with skin-conforming wearables have made it a promising substitute biofluid. Compared to enzyme-based platforms, non-enzymatic glucose sensors have attracted a lot of attention recently because of their greater stability, extended operating lifetime, and resistance to environmental deterioration. With an emphasis on the electrocatalytic mechanisms, novel materials, flexible substrates, and microfluidic integration techniques that allow precise detection of ultralow glucose concentrations in human sweat, this review provides a thorough overview of developments in non-enzymatic, sweat-based glucose sensing. Sensitivity, selectivity, and wearing compatibility are examined in connection to important material types, including as transition metals, metal oxides/hydroxides, noble metals, carbon nanomaterials, and hybrid composites. Along with commercially available sweat-sensing prototypes, recent advances in wireless communication, flexible electronics, and microfluidic sweat harvesting are discussed. The study critically analyses major barriers to clinical translation, such as sweat-rate variability, interference from electroactive species, sensor fouling, and challenges associated with accurate calibration. Lastly, future perspectives highlight the necessity of large-scale human validation, uniform calibration models, AI-based data processing, and multiparameter sensing. The purpose of this review is to direct the creation of wearable platforms for non-invasive glucose monitoring that are next-generation, dependable, and customized.