Tang Wenying, Chen Zhesi, Song Zhilong, Wang Chen, Wan Zhu'an, Chan Chak Lam Jonathan, Chen Zhuo, Ye Wenhao, Fan Zhiyong
Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China.
The Hong Kong University of Science and Technology-Shenzhen Research Institute, Shenzhen 518057, China.
ACS Nano. 2022 Jul 26;16(7):10968-10978. doi: 10.1021/acsnano.2c03372. Epub 2022 Jul 7.
Real-time monitoring of health threatening gases for chemical safety and human health protection requires detection and discrimination of trace gases with proper gas sensors. In many applications, costly, bulky, and power-hungry devices, normally employing optical gas sensors and electrochemical gas sensors, are used for this purpose. Using a single miniature low-power semiconductor gas sensor to achieve this goal is hardly possible, mostly due to its selectivity issue. Herein, we report a dual-mode microheater integrated nanotube array gas sensor (MINA sensor). The MINA sensor can detect hydrogen, acetone, toluene, and formaldehyde with the lowest measured limits of detection (LODs) as 40 parts-per-trillion (ppt) and the theoretical LODs of ∼7 ppt, under the continuous heating (CH) mode, owing to the nanotubular architecture with large sensing area and excellent surface catalytic activity. Intriguingly, unlike the conventional electronic noses that use arrays of gas sensors for gas discrimination, we discovered that when driven by the pulse heating (PH) mode, a single MINA sensor possesses discrimination capability of multiple gases through a transient feature extraction method. These above features of our MINA sensors make them highly attractive for distributed low-power sensor networks and battery-powered mobile sensing systems for chemical/environmental safety and healthcare applications.
为实现化学安全和人类健康保护，对威胁健康的气体进行实时监测需要使用合适的气体传感器来检测和区分痕量气体。在许多应用中，通常采用光学气体传感器和电化学气体传感器来完成此项任务，这些设备成本高昂、体积庞大且耗电量大。仅使用单个微型低功耗半导体气体传感器几乎无法实现这一目标，这主要是由于其选择性问题。在此，我们报告了一种双模微加热器集成纳米管阵列气体传感器（MINA传感器）。MINA传感器在连续加热（CH）模式下，由于具有大传感面积和优异表面催化活性的纳米管结构，能够检测氢气、丙酮、甲苯和甲醛，其最低检测限（LOD）为40万亿分之一（ppt），理论LOD约为7 ppt。有趣的是，与使用气体传感器阵列进行气体区分的传统电子鼻不同，我们发现当由脉冲加热（PH）模式驱动时，单个MINA传感器通过瞬态特征提取方法具备区分多种气体的能力。我们的MINA传感器的上述特性使其对于用于化学/环境安全和医疗保健应用的分布式低功耗传感器网络以及电池供电的移动传感系统极具吸引力。
