INHA IST and Lab of Intelligent of Devices and Thermal Control, Department of Mechanical Engineering, Inha University, Incheon 22212, South Korea.
Department of Chemistry, Sungkyunkwan University, Suwon 16419, South Korea.
J Nanosci Nanotechnol. 2020 Nov 1;20(11):7151-7157. doi: 10.1166/jnn.2020.18851.
Recently, efforts have been made to adapt surface acoustic waves (SAWs) for use in chemical sensors for detection of chemical warfare agents (CWAs). In this study, a four-channel real-time CWA detection system was constructed using four 250-MHz SAW sensors. Each system consists of three different chemical sensors and one reference sensor. The reference sensor compensates for frequency variations according to humidity and temperature conditions. Signals from the SAW sensors can be checked on a PC-based graphical user interface without additional measuring equipment. To measure dimethyl methylphosphonate (DMMP), a simulant of sarin gas, polyhedral oligomeric silsesquioxane (POSS) and thiourea (TU)-based synthetic polymers were used as sensing materials. The reference sensor was not coated, whereas the three different chemical sensors were coated with POSS, TU-1, and TU-2. The maximum frequencies of POSS, TU-1, and TU-2 were shifted 15.86, 13.85, and 0.944 kHz, showing significant values. We also found a relatively good linear relation between the frequency shift and the concentration of DMMP. The three sensing materials selected-POSS, TU-1, and TU-2-responded significantly to DMMP and triethylphosphate in the selectivity tests. This response is due to the chemical bonding of the sensing materials with the phosphonate in the nerve-agent simulants. These results indicate that the four-channel SAW monitoring system described in this paper shows potential as a portable real-time monitoring system to detect a variety of toxic vapors simultaneously, without using complex measuring equipment. In addition, this approach has demonstrated potential for developing excellent portable sensors to detect different types of CWAs.
最近，人们努力将表面声波（SAWs）应用于化学传感器，以检测化学战剂（CWAs）。在这项研究中，使用四个 250MHz 的 SAW 传感器构建了一个四通道实时 CWA 检测系统。每个系统由三个不同的化学传感器和一个参考传感器组成。参考传感器根据湿度和温度条件补偿频率变化。无需额外的测量设备，就可以在基于 PC 的图形用户界面上检查 SAW 传感器的信号。为了测量沙林气体的模拟物二甲基甲基膦酸酯（DMMP），使用多面体低聚倍半硅氧烷（POSS）和硫脲（TU）基合成聚合物作为传感材料。参考传感器未涂覆，而三个不同的化学传感器则涂覆有 POSS、TU-1 和 TU-2。POSS、TU-1 和 TU-2 的最大频率分别偏移了 15.86、13.85 和 0.944 kHz，显示出显著的值。我们还发现，频率偏移与 DMMP 浓度之间存在较好的线性关系。在选择性测试中，所选的三种传感材料-POSS、TU-1 和 TU-2-对 DMMP 和三乙膦酸酯有明显的响应。这种响应归因于传感材料与神经毒剂模拟物中的膦酸酯的化学结合。这些结果表明，本文描述的四通道 SAW 监测系统具有作为同时检测多种有毒蒸气的便携式实时监测系统的潜力，而无需使用复杂的测量设备。此外，这种方法已经证明了开发用于检测不同类型 CWAs 的出色便携式传感器的潜力。
