人体呼吸气体检测对于疾病的早期无创诊断有重要现实意义。目前用于呼气检测的氧化物半导体气体传感器存在选择性差、灵敏度低和湿度干扰大的瓶颈问题。申请人突破常规的氧化物半导体气体传感材料的构筑策略，提出利用高湿环境下（呼吸气体湿度超过97% RH）特征呼出气体在非共轭聚合物/电极界面的溶解、电离和传导特性，实现对目标气体检测的新方法。利用不同目标气体溶解度、电离度以及离子迁移率的差异，实现传感器选择性和灵敏度的提高。本项目中，研究生物功能型材料的功能化修饰，提高器件的灵敏度；研究纸基呼气传感器的结构设计，获得低成本的柔性室温氨气传感器；研究水分子和目标气体在绝缘聚合物表面的相互作用行为，揭示新原理气体传感器的感知机理。最终实现高湿环境下1 ppm氨气的高灵敏、选择性检测。

Human exhale gas detection has greatl significance for the early non-invasive diagnosis of diseases. However, traditional semiconductor gas sensors are difficult to meeting the need of exhale gas detection due to the poor selectivity and high humidity interference. Here, we present a novel gas sensing mechenism, which utilizes the dissolution, ionization and ion trasportation process of target gas at polymer/electrode interface under high humidity (humidity of exhale gas exceeding 97% RH) to realize the slective detection of the target gas. The selectivity of the sensor can be improved by utilizing the differences of solubility, ionization and ion mobility between different gas. In this project, the functional modification of compatible materials for human physiological environment is studied to improve the sensitivity of the device; the paper-based sensor is developed to obtain low-cost flexible room temperature ammonia sensor; the interaction behavior of water molecules and target gases on the surface of polymers is studied, and the sensing mechanism of the gas sensor is revealed. Finally, the high sensitivity and selectivity detection of 1 ppm ammonia in high humidity environment is realized.