School of Intelligent Engineering, Shaoguan University, Shaoguan Guangdong 363000 China.
School of Intelligent Engineering, Shaoguan University, Shaoguan Guangdong 363000 China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Nov 5;280:121527. doi: 10.1016/j.saa.2022.121527. Epub 2022 Jun 18.
The interaction between the terahertz wave propagating in free space and the sample is weak, which leads to the weak signal of the sample, which cannot meet the detection needs of trace samples. In order to meet the detection of trace samples, a kind of metamaterial absorber (the basic unit of the absorber is composed of gold-high resistance silicon-aluminum three-layer structure) is designed, and the monolayer graphene is transferred on the surface of the metamaterial absorber to construct the graphene-metamaterial absorber heterostructure. The transmission spectrum of the resonant cavity is simulated and measured by terahertz time domain spectroscopy system, and the obvious resonance frequency shift is observed. The results show that the graphene-metamaterial absorber heterostructure can detect josamycin antibiotic solution with concentration of 0.02 mg/L (the mass of josamycin is 0.2 ng). Compared with using the same structure metamaterial absorber to detect josamycin antibiotics, the sensitivity is increased by an order of magnitude. Using graphene-metamaterial heterostructure to detect the relative change of heterostructure reflectivity caused by josamycin antibiotics can reach 40%. The research in this paper provides a new technical means for accurate and rapid detection in terahertz band.
太赫兹波在自由空间中传播时与样品的相互作用较弱，导致样品的信号较弱，无法满足痕量样品的检测需求。为了满足痕量样品的检测，设计了一种超材料吸收体（吸收体的基本单元由金-高阻硅-铝三层结构组成），并在超材料吸收体表面转移单层石墨烯，构建了石墨烯-超材料吸收体异质结。通过太赫兹时域光谱系统对谐振腔的透射谱进行了模拟和测量，观察到明显的共振频率移动。结果表明，石墨烯-超材料吸收体异质结可以检测浓度为 0.02mg/L 的交沙霉素抗生素溶液（交沙霉素的质量为 0.2ng）。与使用相同结构超材料吸收体检测交沙霉素抗生素相比，灵敏度提高了一个数量级。使用石墨烯-超材料异质结检测交沙霉素抗生素引起的异质结反射率的相对变化可达 40%。本文的研究为太赫兹波段的精确快速检测提供了新的技术手段。
