Investigation of Cortisol Dynamics in Human Sweat Using a Graphene-Based Wireless mHealth System

• Published in: Matter Vol. 2; no. 4; pp. 921 - 937
• Main Authors: Torrente-Rodríguez, Rebeca M., Tu, Jiaobing, Yang, Yiran, Min, Jihong, Wang, Minqiang, Song, Yu, Yu, You, Xu, Changhao, Ye, Cui, IsHak, Waguih William, Gao, Wei
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2020
• Subjects: cortisol; flexible sensors; graphene; mHealth; stress hormone; stress response; sweat; cortisol; stress response; mHealth; sweat; flexible sensors; stress hormone; MAP3: Understanding; graphene
• ISSN: 2590-2385; 2590-2393; 2590-2385
• DOI: 10.1016/j.matt.2020.01.021

Understanding and assessing endocrine response to stress is crucial to human performance analysis, stress-related disorder diagnosis, and mental health monitoring. Current approaches for stress monitoring are largely based on questionnaires, which could be very subjective. To avoid stress-inducing blood sampling and to realize continuous, non-invasive, and real-time stress analysis at the molecular levels, we investigate the dynamics of a stress hormone, cortisol, in human sweat using an integrated wireless sensing device. Highly sensitive, selective, and efficient cortisol sensing is enabled by a flexible sensor array that exploits the exceptional performance of laser-induced graphene for electrochemical sensing. Here, we report the first cortisol diurnal cycle and the dynamic stress-response profile constructed from human sweat. Our pilot study demonstrates a strong empirical correlation between serum and sweat cortisol, revealing exciting opportunities offered by sweat analysis toward non-invasive dynamic stress monitoring via wearable and portable sensing platforms. [Display omitted] •A fully integrated, flexible, and wireless device for sweat cortisol monitoring•Mass-producible graphene sensor array for sensitive and reliable measurements•A strong correlation between serum and sweat cortisol is obtained•The diurnal cycle and stress-response profile of sweat cortisol are reported Prompt and accurate detection of stress is essential to the monitoring and management of mental health and human performance. Considering that current methods such as questionnaires are very subjective, we propose a highly sensitive, selective, miniaturized mHealth device based on laser-enabled flexible graphene sensor to non-invasively monitor the level of stress hormones (e.g., cortisol). We report a strong correlation between sweat and circulating cortisol and demonstrate the prompt determination of sweat cortisol variation in response to acute stress stimuli. Moreover, we demonstrate, for the first time, the diurnal cycle and stress-response profile of sweat cortisol, revealing the potential of dynamic stress monitoring enabled by this mHealth sensing system. We believe that this platform could contribute to fast, reliable, and decentralized healthcare vigilance at the metabolic level, thus providing an accurate snapshot of our physical, mental, and behavioral changes. A fully integrated, flexible, and miniaturized wireless mHealth sensing device based on laser-engraved graphene and immunosensing with proven utility for fast, reliable, sensitive, and non-invasive monitoring of stress hormone cortisol is developed. Pilot human study results revealed a strong correlation between sweat and circulating hormone for the first time. Both cortisol diurnal cycle and dynamic stress-response profiles were established from human sweat, reflecting the potential of such mHealth devices in personalized healthcare and human performance evaluation.