Enhanced sensitivity in THz plasmonic sensors with silver nanowires
Enhanced sensitivity in THz plasmonic sensors with silver nanowires
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DOI：
10.1038/s41598-018-33617-2
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发表时间：
2018-10-19
影响因子：
4.6
通讯作者：
Ahn, Y. H.
中科院分区：
文献类型：
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作者：
Hong, J. T.;Jun, S. W.;Ahn, Y. H.
我们开发了用于太赫兹频段微生物传感的混合缝隙天线结构，其中使用了银纳米线(AgNW)来提高灵敏度。为了制作混合器件，我们在缝隙天线区部分刻蚀了AgNW，在那里我们可以预期到AgNW尖端的场增强效应。我们测量了在沉积聚合物层时观察到的共振频率漂移，并观察到引入AgNW后灵敏度增加，增强系数超过四倍(按优值系数计算约为六倍)。敏感度随着AgNW浓度的增加而增加，直至饱和。此外，我们对带有PRD1病毒的器件进行了测试，在缝隙天线宽度为3微米时，得到了3.4的增强因子。此外，我们还进行了时域有限差分仿真，验证了实验结果。灵敏度增强因子随缝隙宽度的减小而减小，与实验结果一致。电场的二维图证实了AgNW尖端的强场局部化和增强。
We developed hybrid slot antenna structures for microbial sensing in the THz frequency range, where silver nanowires (AgNWs) were employed to increase the sensitivity. In order to fabricate the hybrid devices, we partially etched the AgNW in the slot antenna region, where we can expect the field enhancement effect at the AgNW tip. We measured the resonant-frequency shift observed upon the deposition of a polymer layer, and observed that the sensitivity increased upon the introduction of AgNWs, with an enhancement factor of more than four times (approximately six times in terms of figure-of-merit). The sensitivity increased with the AgNW density until saturation. In addition, we tested devices with PRD1 viruses, and obtained an enhancement factor of 3.4 for a slot antenna width of 3 mu m. Furthermore, we performed finite-difference time-domain simulations, which confirmed the experimental results. The sensitivity enhancement factor decreased with the decrease of the slot width, consistent with the experimental findings. Two-dimensional mapping of the electric field confirmed the strong field localization and enhancement at the AgNW tips.