Wearable Breath Gas Sensors for Chronic Disease Management: Challenges and Perspectives

ABSTRACT Exhaled breath contains diverse volatile organic compounds (VOCs) and inorganic gases as non‐invasive biomarkers for chronic disease management. While conventional gas analysis techniques like gas chromatography offer high sensitivity, their bulky instruments, high costs, and operational complexity hinder routine and personal use. Recent advances in wearable technologies have opened new opportunities for real‐time, continuous, and non‐invasive monitoring of disease‐related gas biomarkers. Although several sensors are applicable in laboratory or small cohort studies, few devices have undergone large‐scale clinical validation, and translation to routine clinical use remains limited. This review highlights the latest progress in wearable platforms, including masks, wrist bands, patches, e‐textiles, and non‐conventional systems. It explores key sensing materials, device engineering, and sensor systems for clinically relevant biomarkers such as nitric oxide, carbon monoxide, ammonia, acetone, and multi‐analyte VOC profiles associated with various chronic diseases. Challenges in achieving sub‐ppb/sub‐ppm sensitivity, ensuring selectivity in humid environments, long‐term stability, reliable calibration, user comfort, and data security remain. Future progress hinges on multi‐modal sensing, enhanced durability, AI‐powered data analytics, telemedicine integration, and regulatory standardization. With the advances in materials science, flexible electronics, and digital health, wearable breath gas sensors are poised to revolutionize personalized, preventive care for chronic diseases.