A hot-humid tolerant and antibacterial MXene-based hydrogel sensor for real-time cardiorespiratory monitoring in endurance sports.

Wearable sensors for continuous physiological monitoring during intense exercise face significant challenges, including motion artifacts and skin discomfort. Conductive hydrogels offer a promising solution due to their skin-like flexibility and excellent electrical conductivity, yet their application in extreme conditions like marathon running remains challenges. Here, we develop a MXene-based dual-network hydrogel composed of polyvinyl alcohol (PVA) and tempo-oxidized cellulose nanofibers (TOCNF) crosslinked with MXene nanosheets and borax. This hydrogel exhibits exceptional environmental stability (35 days at 4 °C and 30% relative humidity) and strain sensitivity (gauge factor of 7.79 at 800% strain), while MXene integration provides outstanding antibacterial properties (>99% inhibition). As a proof of concept, under simulated marathon conditions (38°C, 52% relative humidity), the sensor maintains stable performance for 6 h, demonstrating reliable heart rate and respiration monitoring. These capabilities are crucial for identifying early signs of cardiorespiratory abnormalities during endurance sports. Our work presents a robust strategy for developing wearable hydrogel sensors with long-term reliability in extreme environments, offering significant potential for sports medicine, exercise physiology, and continuous health monitoring applications.