Metamaterial-Free Flexible Graphene-Enabled Terahertz Sensors for Pesticide Detection at Bio-Interface
| Autor: | Wendao Xu, Jifan Yin, Qi Wang, Ruiyun Zhou, Yibin Ying, Junichiro Kono, Lijuan Xie, Yuxin Huang, Jianfeng Ping |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Fabrication Terahertz radiation Surface Properties 02 engineering and technology 010402 general chemistry 01 natural sciences law.invention symbols.namesake law Robustness (computer science) General Materials Science Particle Size Pesticides Spectroscopy Terahertz Spectroscopy business.industry Graphene Fermi level Metamaterial 021001 nanoscience & nanotechnology 0104 chemical sciences Malus symbols Optoelectronics Graphite 0210 nano-technology business Contact area |
| Zdroj: | ACS applied materialsinterfaces. 12(39) |
| ISSN: | 1944-8252 |
| Popis: | 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 π 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. |
| Databáze: | OpenAIRE |
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