Wearable Electrochemical Sensors for Cortisol Monitoring in Body Fluids: From Materials to Applications

Abstract

Cortisol, a steroid hormone, is critical in regulating the stress response, metabolic homeostasis, and immune balance in the human body. Since cortisol is widely distributed in body fluids, the use of easily accessible fluids, such as sweat, makes continuous health assessment possible. Wearable sensors support the non-invasive and in situ collection of biomarkers, while electrochemical sensing methods have been widely used for the analysis of biomarkers due to their low cost, easy operation, high sensitivity, and fast response. The development and application of wearable electrochemical sensors provide essential support for non-invasive, real-time, and continuous monitoring of cortisol. This review systematically covers the recent progress in wearable electrochemical sensors, focusing particularly on sensing strategies of different recognition elements and critically evaluating their performance and limitations in complex biological fluids. Additionally, this review introduces the innovative applications of graphene, MXene, metal nanoparticles, and other functional materials in wearable electrochemical sensors, systematically comparing the sensing abilities of each material. Subsequently, in view of the challenges encountered in practical applications, this work discusses microfluidic integration strategies, multilayer interference-resistant interface designs, and machine learning-based data calibration methods. Finally, future prospects for interdisciplinary approaches in advancing precision medicine and real-time health monitoring are reviewed.