Centre for Intelligent Antenna and Radio Systems (CIARS), Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, N2L 3G1, Canada.
Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, N2L 3G1, Canada.
Sci Rep. 2022 Oct 22;12(1):17747. doi: 10.1038/s41598-022-21015-8.
Spectroscopy in the sub-terahertz (sub-THz) range of frequencies has been utilized to study the picosecond dynamics and interaction of biomolecules. However, widely used free-space THz spectrometers are typically limited in their functionality due to low signal-to-noise ratio and complex setup. On-chip spectrometers can revolutionize THz spectroscopy allowing integration, compactness, and low-cost fabrication. In this paper, a low-loss silicon-based platform is proposed for on-chip sub-THz spectroscopy. Through functionalization of silicon chip and immobilization of bio-particles, we demonstrate the ability to characterize low-loss nano-scale biomolecules across the G-band (0.14-0.22 THz). We also introduce an electromagnetic thin-film model to account for the loading effect of the immobilized biomolecules, i.e. dehydrated streptavidin and immunoglobulin antibody, as two key molecules in the biosensing discipline. The proposed platform was fabricated using a single mask micro-fabrication process, and then measured by a vector network analyzer (VNA), which offers high dynamic range and high spectral resolution measurements. The proposed planar platform is general and paves the way towards low-loss, cost-effective and integrated sub-THz biosensors for the detection and characterization of biomolecules.
在亚太赫兹（sub-THz）频率范围内的光谱学已被用于研究生物分子的皮秒动力学和相互作用。然而，由于信噪比低和复杂的设置，广泛使用的自由空间太赫兹光谱仪通常在功能上受到限制。片上光谱仪可以彻底改变太赫兹光谱学，允许集成、紧凑和低成本制造。本文提出了一种基于低损耗硅的片上亚太赫兹光谱学平台。通过硅片的功能化和生物颗粒的固定化，我们展示了在 G 带（0.14-0.22 THz）范围内对低损耗纳米级生物分子进行特征化的能力。我们还引入了一个电磁薄膜模型来解释固定化生物分子的加载效应，即脱水链霉亲和素和免疫球蛋白抗体，它们是生物传感领域的两个关键分子。所提出的平台是使用单个掩模微制造工艺制造的，然后使用矢量网络分析仪（VNA）进行测量，该分析仪提供高动态范围和高光谱分辨率测量。所提出的平面平台具有通用性，为低成本、集成的亚太赫兹生物传感器的检测和生物分子的特征化铺平了道路。
