Xu Wendao, Wang Qi, Zhou Ruiyun, Hameed Saima, Ma Yungui, Ying Yibin
College of Biosystems Engineering and Food Science, Zhejiang University 866 Yuhangtang Rd. 310058 Hangzhou P.R. China
Key Laboratory of Intelligent Equipment and Robotics for Agriculture of Zhejiang Province P.R. China.
RSC Adv. 2022 Oct 7;12(44):28678-28684. doi: 10.1039/d2ra06006j. eCollection 2022 Oct 4.
Performing sensitive and selective detection in a mixture is challenging for terahertz (THz) sensors. In light of this, many methods have been developed to detect molecules in complex samples using THz technology. Here we demonstrate a defect-rich monolayer graphene-coated metamaterial operating in the THz regime for pesticide sensing in a mixture through strong local interactions between graphene and external molecules. The monolayer graphene induces a 50% change in the resonant peak excited by the metamaterial absorber that could be easily distinguished by THz imaging. We experimentally show that the Fermi level of the graphene can be tuned by the addition of molecules, which agrees well with our simulation results. Taking chlorpyrifos methyl in the lixivium of rice as a sample, we further show the molecular sensing potential of this device, regardless of whether the target is in a mixture or not.
对太赫兹（THz）传感器而言，在混合物中进行灵敏且选择性的检测颇具挑战。鉴于此，人们已开发出诸多方法，利用太赫兹技术检测复杂样品中的分子。在此，我们展示了一种富含缺陷的单层石墨烯包覆超材料，其在太赫兹波段工作，通过石墨烯与外部分子之间强烈的局部相互作用，用于检测混合物中的农药。单层石墨烯使超材料吸收体激发的共振峰产生50%的变化，这可通过太赫兹成像轻易辨别。我们通过实验表明，添加分子可调节石墨烯的费米能级，这与我们的模拟结果吻合良好。以大米浸出液中的甲基毒死蜱为样本，我们进一步展示了该器件的分子传感潜力，无论目标是否处于混合物中。
