Large‐Scale Flexible Fabric Biosensor for Long‐Term Monitoring of Sweat Lactate

Abstract Integrating sweat biosensors into daily wear has the potential to effectively monitor personal lactate levels, offering the advantages of convenience, precision, and multi‐point detection. However, existing wearable fabric sweat biosensors have limitations in terms of long‐term repeatable detection and washability due to the difficulty of building a stable layer of recognition materials on the highly curved fiber surface. Here, a long‐term repeatable and washable electrochemical fabric biosensor is reported based on a fiber electrode with multi‐scaled aligned channels for efficient and reliable lactate detection. Through the functionalization of a molecularly imprinted polymer with redox‐sensitive nano reporters, the fabric biosensor exhibits impressive in situ long‐term repeatable detection for more than 400 times, washability, and stability under deformations. The multi‐scaled channels contribute to a desired electric field distribution and thus a reliable interface between the polymer and the fiber. Employing industrial sewing technology, a 20 m (L) × 0.5 m (W) sensing fabric is further produced. Ultimately, combined with a wireless communication element, the fabric biosensing system can immediately track lactate levels.