Department of Electrical Engineering, University of California , Los Angeles, California 90095, United States.
Nano Lett. 2013 Nov 13;13(11):5271-6. doi: 10.1021/nl4027692. Epub 2013 Oct 10.
This work reports on zeolitic imidazolate framework (ZIF)-coupled microscale resonators for highly sensitive and selective gas detection. The combination of microscale resonators and nanoscale materials simultaneously permits the benefit of larger capture area for adsorption from the resonator and enhanced surface adsorption capacity from the nanoscale ZIF structure. Dielectrophoresis (DEP) was demonstrated as a novel method for directly assembling concentrated ZIF nanoparticles on targeted regions of silicon resonant sensors. As part of the dielectrophoretic assembly process, the first ever measurements of the Clausius-Mossotti factor for ZIFs were conducted to determine optimal conditions for DEP assembly. The first ever real-time adsorption measurements of ZIFs were also performed to investigate the possibility of inherent gas selectivity. The ZIF-coupled resonators demonstrated sensitivity improvement up to 150 times over a bare silicon resonator with identical dimensions, and real-time adsorption measurements of ZIFs revealed different adsorption time constants for IPA and CO2.
这项工作报道了沸石咪唑酯骨架（ZIF）耦合微尺度谐振器在高灵敏度和选择性气体检测方面的应用。微尺度谐振器和纳米尺度材料的结合同时允许从谐振器获得更大的吸附捕获面积，并从纳米尺度 ZIF 结构获得增强的表面吸附能力。介电泳（DEP）被证明是一种在硅谐振传感器的目标区域上直接组装浓缩 ZIF 纳米粒子的新方法。作为介电泳组装过程的一部分，首次对 ZIF 的克劳修斯-莫索蒂因子进行了测量，以确定 DEP 组装的最佳条件。首次对 ZIF 的实时吸附测量也进行了研究，以研究固有气体选择性的可能性。与具有相同尺寸的裸硅谐振器相比，ZIF 耦合谐振器的灵敏度提高了 150 倍，而 ZIF 的实时吸附测量揭示了 IPA 和 CO2 的不同吸附时间常数。
