MXene-based wireless facemask enabled wearable breath acetone detection for lipid metabolic monitoring

Breath acetone (BrAC) detection presents a promising scheme for noninvasive monitoring of metabolic health due to its close correlation to diets and exercise-regulated lipolysis. Herein, we report a Ti₃C₂T_x MXene-based wireless facemask for on-body BrAC detection and real-time tracking of lipid metabolism, where Ti₃C₂T_x MXene serves as a versatile nanoplatform for not only acetone detection but also breath interference filtration. The incorporation of in situ grown TiO₂ and short peptides with Ti₃C₂T_x MXene further improves the acetone sensitivity and selectivity, while TiO₂-MXene interfaces facilitate light-assisted response calibration. To further realize wearable breath monitoring, a miniaturized flexible detection tag has been integrated with a commercially available facemask, which enables facile BrAC detection and wireless data transmission. Through the hierarchically designed filtration-detection-calibration-transmission system, we realize BrAC detection down to 0.31 ppm (part per million) in breath. On-body breath tests validate the facemask in dynamically monitoring of lipid metabolism, which could guide dieter, athletes, and fitness enthusiasts to arrange diets and exercise activities. The proposed wearable platform opens up new possibility toward the practice of breath analysis as well as daily lipid metabolic management.