Park S J, Son B H, Choi S J, Kim H S, Ahn Y H
Opt Express. 2014 Dec 15;22(25):30467-72. doi: 10.1364/OE.22.030467.
We demonstrated sensitive detection of individual yeast cells and yeast films by using slot antenna arrays operating in the terahertz frequency range. Microorganisms located at the slot area cause a shift in the resonant frequency of the THz transmission. The shift was investigated as a function of the surface number density for a set of devices fabricated on different substrates. In particular, sensors fabricated on a substrate with relatively low permittivity demonstrate higher sensitivity. The frequency shift decreases with increasing slot antenna width for a fixed coverage of yeast film, indicating a field enhancement effect. Furthermore, the vertical range of the effective sensing volume has been studied by varying the thickness of the yeast film. The resonant frequency shift saturates at 3.5 μm for a slot width of 2 μm. In addition, the results of finite-difference time-domain simulations are in good agreement with our experimental data.
我们展示了通过使用在太赫兹频率范围内工作的缝隙天线阵列对单个酵母细胞和酵母膜进行灵敏检测。位于缝隙区域的微生物会导致太赫兹传输的共振频率发生偏移。对于在不同衬底上制造的一组器件，研究了该偏移作为表面数密度的函数。特别地，在相对低介电常数的衬底上制造的传感器表现出更高的灵敏度。对于固定覆盖的酵母膜，随着缝隙天线宽度增加，频率偏移减小，这表明存在场增强效应。此外，通过改变酵母膜的厚度研究了有效传感体积的垂直范围。对于2μm的缝隙宽度，共振频率偏移在3.5μm处达到饱和。此外，时域有限差分模拟结果与我们的实验数据吻合良好。
