Non-enzymatic electrochemical sensor for wearable monitoring of sweat biomarkers: A mini-review

Sweat contains a wealth of health-related biomarkers, which has been a promising resource for personalized real-time monitoring at molecular level. Emergence of non-enzymatic electrochemical sensor that simulates the enzyme catalysis utilizing the functional material further promotes the development of wearable sweat sensor, successfully addressing the limitations of enzyme sensing in sensitivity and stability. Thus, there is an urgent need for centering on the regulation of the nanostructure, combination and preparation method of functional materials to enhance the catalytic activity for enzyme-free detection of sweat biomarkers. This review aims to present the superiors of enzyme-free sensing on wearable sweat sensor, and provides guidance for material innovation, sensor design and system integration. Firstly, we primarily focus on the recent advances of novel functional nanomaterials in wearable non-enzymatic electrochemical sensor, and briefly describe the sensing principles for detecting biomarkers in sweat. Subsequently, the correlation between the electrochemical strategy and functional material is elaborately interpreted by coupling with the diverse molecular structures of the biomarkers and the pH changes of test environments. Finally, challenges and opportunities for wearable non-enzymatic electrochemical sensor in sweat sensing are delineated in the development of future personalized healthcare.