Xu Shipu, Zhou Xuehan, Xu Shidang, Zhang Yan, Shi Yiwen, Cong Xuzhong, Xu Qijia, Tian Ye, Jiang Ying, Guo Hanjie, Zhao Jinkui, Sun Fengqiang, Peng Hailin
Songshan Lake Materials Laboratory, Dongguan, PR China.
School of Microelectronics Science and Technology, Sun Yat-sen University, Zhuhai, PR China.
Nat Commun. 2024 Jul 16;15(1):5991. doi: 10.1038/s41467-024-50443-5.
Trace NO detection is essential for the production and life, where the sensing strategy is appropriate for rapid detection but lacks molecular specificity. This investigation proposes a sensing mechanism dominated by surface-scattering to achieve the molecularly-specific detection. Two-dimensional BiOSe is firstly fabricated into a Schottky-junction-based gas-sensor. Applied with an alternating excitation, the sensor simultaneously outputs multiple response signals (i.e., resistance, reactance, and the impedance angle). Their response times are shorter than 200 s at room temperature. In NO sensing, these responses present the detection limit in ppt range and the sensitivity is up to 16.8 %·ppb. This NO sensitivity presents orders of magnitude higher than those of the common gases within the exhaled breath. The impedance angle is involved in the principle component analysis together with the other two sensing signals. Twelve kinds of typical gases containing NO are acquired with molecular characteristics. The change in dipole moment of the target molecule adsorbed is demonstrated to correlate with the impedance angle via surface scattering. The proposed mechanism is confirmed to output ultra-sensitive sensing responses with the molecular characteristic.
痕量一氧化氮（NO）检测对生产生活至关重要，现有的传感策略虽适用于快速检测，但缺乏分子特异性。本研究提出一种以表面散射为主导的传感机制，以实现分子特异性检测。首先将二维BiOSe制成基于肖特基结的气体传感器。施加交变激励后，该传感器同时输出多个响应信号（即电阻、电抗和阻抗角）。在室温下，它们的响应时间短于200秒。在NO传感中，这些响应的检测限在ppt范围内，灵敏度高达16.8%·ppb。这种对NO的灵敏度比呼出气体中的常见气体高出几个数量级。阻抗角与其他两个传感信号一起参与主成分分析。获取了包含NO的十二种典型气体的分子特征。结果表明，吸附的目标分子偶极矩的变化通过表面散射与阻抗角相关。所提出的机制被证实能够输出具有分子特征的超灵敏传感响应。
