Detection of vapor phase analytes and gas molecules is primarily essential for numerous applications including medical diagnostic, environmental monitoring, chemical threat detection, food quality control, and chemical warfare agents. Here, we developed Caffeine functionalized carbon nanotubes (CNTs) random network based vapor quantum resistive sensors (vQRSs) for volatile organic compounds (VOCs) detection. The localized transmission electron microscopy (TEM) image and energy dispersive X-ray spectroscopy (EDS) confirm migration of caffeine to CNT–CNT junction (CNTj). We have recorded more than one order of magnitude higher sensitivity and unique selectivity towards​ selective VOCs (e.g., acetone, toluene, ethanol, methanol, etc.) with short response time (few seconds) for caffeine modified CNT junction (Caf-CNTj) vQRSs. Molecular dynamics (MD) calculations suggest that the sensitivity of the sensor is diffusion limited, with an advective contribution for ethanol. The designed Caf-CNTj sensors can potentially be important candidate to be a part of electronic nose used for various application such as breath analysis and food quality monitoring.

气相分析物和气体分子的检测对于许多应用而言至关重要，包括医学诊断，环境监测，化学威胁检测，食品质量控制和化学战剂。在这里，我们开发了基于咖啡因功能化的碳纳米管（CNT）的基于随机网络的气相量子电阻传感器（vQRSs），用于检测挥发性有机化合物（VOC）。局部透射电子显微镜（TEM）图像和能量色散X射线光谱（EDS）证实咖啡因迁移至CNT-CNT结（CNTj）。我们已经记录了对选择性VOC（例如丙酮，甲苯，乙醇，甲醇等）的高灵敏度和独特选择性的咖啡因修饰的CNT连接（Caf-CNTj）响应时间短（几秒钟）的数量级提高了一个数量级以上。 vQRSs。分子动力学（MD）计算表明，传感器的灵敏度受到扩散限制，对乙醇有平流作用。设计的Caf-CNTj传感器可能会成为重要的候选者，成为电子鼻的一部分，用于各种应用，例如呼吸分析和食品质量监控。