Metamaterial-Free Flexible Graphene-Enabled Terahertz Sensors for Pesticide Detection at Bio-Interface
Metamaterial-Free Flexible Graphene-Enabled Terahertz Sensors for Pesticide Detection at Bio-Interface
复制标题
用于生物界面农药检测的无超材料柔性石墨烯太赫兹传感器
DOI：
10.1021/acsami.0c11461
复制
发表时间：
2020-09-30
影响因子：
9.5
通讯作者：
Ying, Yibin
中科院分区：
文献类型：
--
作者：
Xu, Wendao;Huang, Yuxin;Ying, Yibin
太赫兹（THz）光谱技术可以用于高灵敏度的分子传感，这一点越来越受到人们的重视。因此，近年来，许多工作致力于开发柔性、紧凑和高灵敏度的THz传感器。然而，大多数设计采用超材料，这需要复杂且通常昂贵的制造过程。此外，超材料结构在传感器表面和目标表面之间产生间隙，这减小了它们之间的有效接触面积，导致感测性能降低。在这里，我们制作了一个超材料的自由石墨烯为基础的太赫兹传感器与用户设计的模式，在生物界面的传感。外部分子可以与石墨烯中的π电子强烈相互作用，从而移动费米能级并改变THz吸收量。用该传感器成功地检测了甲基毒死蜱，检测限为0.13mg/L。我们还在苹果表面检测到浓度为0.60 mg/L的农药分子，揭示了这种传感器的灵活性。柔性石墨烯THz传感器在1000次弯曲循环中显示出高的传感稳定性和鲁棒性。这些结果表明，我们的石墨烯基薄膜传感器易于制造，灵活，通用，适用于广泛的传感应用。
There is an increasing recognition that terahertz (THz) spectroscopy can be used for high-sensitivity molecular sensing. Therefore, in recent years, much work has been devoted to developing flexible, compact, and high-sensitivity THz sensors. However, most designs employ metamaterials, which require complicated, and often expensive, fabrication procedures. Also, the metamaterial structures create a gap between the sensor surface and the target surface, which decreases the effective contact area between them, resulting in reduced sensing performance. Here, we fabricated a metamaterial-free graphene-based THz sensor with user-designed patterns for sensing at bio-interfaces. External molecules can strongly interact with pi electrons in graphene, which moves the Fermi level and changes the amount of THz absorption. We used this sensor to successfully detect chlorpyrifos methyl with a limit of detection at 0.13 mg/L. We also detected pesticide molecules of a concentration of 0.60 mg/L on the surface of an apple, revealing the flexibility of this sensor. The flexible graphene THz sensor showed high sensing stability and robustness over 1000 cycles of bending. These results show that our graphene-based thin-film sensors are easy to fabricate, flexible, versatile, and suited for a wide range of sensing applications.