Metamaterial-Free Flexible Graphene-Enabled Terahertz Sensors for Pesticide Detection at Bio-Interface

• DOI: 10.1021/acsami.0c11461
• Publication Date: 2020-09-07T18:48:46Z
• Authors: Wendao Xu; Yuxin Huang; Ruiyun Zhou; Qi Wang; Jifan Yin; Junichiro Kono; Jianfeng Ping; Lijuan Xie; Yibin Ying
• Keywords: Terahertz Spectroscopy; Surface Properties; Malus; Graphite; 02 engineering and technology; Particle Size; Pesticides; 0210 nano-technology

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 THz sensors. However, most designs employ metamaterials, which require complicated, often expensive, fabrication procedures. Also, the metamaterial structures create a gap between sensor surface target surface, decreases effective contact area them, resulting reduced sensing performance. Here, we fabricated metamaterial-free graphene-based with user-designed patterns at bio-interfaces. External molecules strongly interact π electrons graphene, moves Fermi level changes amount of absorption. We this successfully detect chlorpyrifos methyl limit detection 0.13 mg/L. also detected pesticide concentration 0.60 mg/L on apple, revealing flexibility sensor. The flexible graphene showed high stability robustness over 1000 cycles bending. These results show our thin-film sensors are easy fabricate, versatile, suited wide range applications.