(Invited) Electrochemical Devices for Sweat-Based Health and Sports Monitoring

Sweat sensing represents a major breakthrough in wearable technology, offering minimally-invasive, real-time monitoring for health and athletic performance [1]. Rich in biomarkers like electrolytes, metabolites, and proteins, sweat mirrors blood composition, making it an effective tool for tracking a wide range of physical conditions [2]. In healthcare, cytokine detection—such as tumor necrosis factor alpha (TNF-α) [3]—is gaining traction for continuous health monitoring. In sports, biomarkers like ammonium $\left(\mathrm{NH}_{4}^{+}\right)$ [4] serve as key indicators of muscle fatigue. Among existing biosensing techniques, electrochemical platforms offer a compact, sensitive, and rapid solution for real-time analyte monitoring in wearable devices [5]. For example, three-electrode sensors (see Fig. 1, left), particularly suitable to detect analytes at $\mathrm{pg} / \mathrm{mL}$ concentration levels, enhances accuracy by stabilizing the reference electrode, ensuring that changes in the working electrode’s potential are due solely to analyte interactions [6]. Electrolyte-gated field-effect transistor (EG-FET)-based biosensors (see Fig. 1, right), on the other hand, offer sensitivity through electrostatic gating, enabling detection of analytes via shifts in transconductance or current [7].