Hasan Mohammad Mahmudul, Alev Onur, Cheffena Michael
Faculty of Engineering, Norwegian University of Science and Technology (NTNU), Gjøvik 2815, Norway.
Department of Physics, Gebze Technical University, 41400 Gebze, Kocaeli, Turkey.
ACS Sens. 2025 Mar 28;10(3):2147-2161. doi: 10.1021/acssensors.4c03393. Epub 2025 Feb 20.
Accurate monitoring of isopropanol (IPA) levels is crucial for safety in industrial and laboratory settings, as high concentrations can lead to serious health issues. In this study, we present, for the first time, a dual-functional antenna sensor capable of high-performance IPA gas detection with concentration estimation and uninterrupted wireless communication, using optimized molecularly imprinted polymer (MIP)/multiwalled carbon nanotube (MWCNT)-based sensing materials. Comprehensive characterization of these materials confirms the successful formation and homogeneity of the composites. Furthermore, the electrical and gas-sensing properties of the sensing materials were evaluated using functionalized interdigitated electrode (IDE)-based sensing structures, optimized for high sensitivity, were functionalized to evaluate the electrical and gas-sensing properties of the materials. These IDE structures, which acted as impedance-varying components during operation, were coupled with a single-port monopole antenna to develop a highly sensitive and selective gas sensor while maintaining uninterrupted communication services. The results showed that the fabricated sensor platform exhibits strong selectivity, sensitivity, and stability for IPA detection at room temperature, effectively distinguishing it from other interference gases. In addition, using the same sensing material, we demonstrated that the antenna-based gas sensor exhibited higher sensitivity than the chemiresistive sensor, achieving a detection limit (18.8 ppm) below the safety thresholds for IPA. Moreover, the antenna's radiation pattern and communication capabilities remained unaffected, ensuring uninterrupted functionality. Detailed optimization process and the sensing mechanism for a novel MIP-based selective antenna gas sensor, supported by both structural and electrical characterizations could serve as a milestone for future studies and the advancement of next-generation sensors.
准确监测异丙醇（IPA）水平对于工业和实验室环境中的安全至关重要，因为高浓度可能导致严重的健康问题。在本研究中，我们首次展示了一种双功能天线传感器，它能够使用优化的基于分子印迹聚合物（MIP）/多壁碳纳米管（MWCNT）的传感材料，对IPA气体进行高性能检测并进行浓度估算以及实现不间断的无线通信。对这些材料的全面表征证实了复合材料的成功形成和均匀性。此外，使用基于功能化叉指电极（IDE）的传感结构评估传感材料的电学和气体传感特性，该结构针对高灵敏度进行了优化，通过功能化来评估材料的电学和气体传感特性。这些IDE结构在运行过程中充当阻抗变化组件，与单端口单极天线耦合，以开发出一种高灵敏度和选择性的气体传感器，同时保持不间断的通信服务。结果表明，所制造的传感器平台在室温下对IPA检测具有很强的选择性、灵敏度和稳定性，能够有效地区分它与其他干扰气体。此外，使用相同的传感材料，我们证明基于天线的气体传感器比化学电阻传感器具有更高的灵敏度，实现了低于IPA安全阈值的检测限（18.8 ppm）。而且，天线的辐射方向图和通信能力不受影响，确保了功能的不间断性。详细的优化过程以及基于新型MIP的选择性天线气体传感器的传感机制，得到了结构和电学表征的支持，可为未来的研究和下一代传感器的发展奠定基础。
