Self-powered sensing system has great application prospect in environmental detection and human health. In this work, a triboelectric nanogenerator (TENG) prepared by Ti₃C₂T_x MXene/amino-functionalized multi-walled carbon nanotubes (MXene/NH₂-MWCNTs) was designed for self-powered detection of exhaled gas and disease diagnosis. The TENG driven by respiration can be used as both a power source and a sensor for the self-powered system. MXene/NH₂-MWCNTs composite sensitive to formaldehyde gas act as both friction layer and electrode of the TENG. The peak-to-peak value of open-circuit voltage and output power from the TENG can reach up to 136 V and 27 μW, respectively. As a self-powered formaldehyde sensor, the device has excellent gas-sensing response (35% @ 5 ppm), low detection limit (10 ppb) and fast response/recovery time (51/57 s). In addition, the respiration-driven TENG can detect formaldehyde in the exhaled gas of smokers and identify respiratory types, which has potential application value in diagnosing diseases related to exhaled gas. Sampling tests were performed for a variety of respiratory types associated with different diseases. Different respiratory types can be identified by using support vector machine model, and the average prediction accuracy is 100%.

自供电传感系统在环境检测和人体健康方面具有很大的应用前景。在这项工作中，设计了一种由 Ti ₃ C ₂ T _x MXene/氨基功能化多壁碳纳米管 (MXene/NH ₂ -MWCNTs) 制备的摩擦纳米发电机 (TENG)，用于自供电检测呼出气和疾病诊断。由呼吸驱动的 TENG 既可以用作自供电系统的电源，也可以用作传感器。MXene/NH ₂-对甲醛气体敏感的MWCNTs复合材料作为TENG的摩擦层和电极。TENG的开路电压和输出功率的峰峰值分别可以达到136 V和27 μW。作为一款自供电甲醛传感器，该设备具有出色的气体传感响应（35% @ 5 ppm）、低检测限（10 ppb）和快速响应/恢复时间（51/57 s）。此外，呼吸驱动的TENG可以检测吸烟者呼出气体中的甲醛并识别呼吸类型，在诊断与呼出气体相关的疾病方面具有潜在的应用价值。对与不同疾病相关的多种呼吸类型进行了抽样测试。利用支持向量机模型可以识别不同的呼吸类型，平均预测准确率为100%。