Electrochemical Tattoo Biosensors for Real-Time Noninvasive Lactate Monitoring in Human Perspiration

TLDR

The study presents the first real‑time, noninvasive lactate sensor in human sweat using a flexible printed tattoo electrochemical biosensor that conforms to skin during exercise. The tattoo biosensor is enzymatic, selectively detects lactate up to 20 mM with linearity, and remains resilient under continuous mechanical deformation typical of epidermal wear. Applied to human subjects during prolonged cycling, the device continuously monitored sweat lactate, revealing intensity‑dependent temporal profiles and demonstrating potential for performance and health monitoring in sports, military, and medical contexts.

Abstract

The present work describes the first example of real-time noninvasive lactate sensing in human perspiration during exercise events using a flexible printed temporary-transfer tattoo electrochemical biosensor that conforms to the wearer's skin. The new skin-worn enzymatic biosensor exhibits chemical selectivity toward lactate with linearity up to 20 mM and demonstrates resiliency against continuous mechanical deformation expected from epidermal wear. The device was applied successfully to human subjects for real-time continuous monitoring of sweat lactate dynamics during prolonged cycling exercise. The resulting temporal lactate profiles reflect changes in the production of sweat lactate upon varying the exercise intensity. Such skin-worn metabolite biosensors could lead to useful insights into physical performance and overall physiological status, hence offering considerable promise for diverse sport, military, and biomedical applications.