Opt Express. 2024 May 6;32(10):16867-16878. doi: 10.1364/OE.518638.
In this paper, a highly integrated terahertz (THz) biosensor is proposed and implemented, which pioneered the preparation of low-temperature gallium arsenide (LT-GaAs) thin film photoconductive antenna (PCA) on the sensor for direct generation and detection of THz waves, simplifying complex terahertz time-domain spectroscopy (THz-TDS) systems. A latch type metasurface is deposited in the detection region to produce a resonance absorption peak at 0.6 THz that is independent of polarisation. Microfluidics is utilised and automatic injection is incorporated to mitigate the experimental effects of hydrogen bond absorption of THz waves in aqueous-based environment. Additionally, cell damage is minimised by regulating the cell flow rate. The biosensor was utilised to detect the concentration of three distinct sizes of bacteria with successful results. The assay was executed as a proof of concept to detect two distinct types of breast cancer cells. Based on the experimental findings, it has been observed that the amplitude and blueshift of the resonance absorption peaks have the ability to identify and differentiate various cancer cell types. The findings of this study introduce a novel approach for developing microfluidic THz metasurface biosensors that possess exceptional levels of integration, sensitivity, and rapid label-free detection capabilities.
本文提出并实现了一种高度集成的太赫兹（THz）生物传感器，该传感器开创性地在传感器上制备了低温砷化镓（LT-GaAs）薄膜光电导天线（PCA），用于直接产生和检测太赫兹波，简化了复杂的太赫兹时域光谱（THz-TDS）系统。在检测区域沉积了锁存型超表面，以在 0.6 THz 处产生与偏振无关的共振吸收峰。利用微流控技术并结合自动进样，以减轻在基于水的环境中太赫兹波氢键吸收的实验影响。此外，通过调节细胞流速来最小化细胞损伤。该生物传感器用于检测三种不同大小的细菌浓度，取得了成功的结果。该测定方法是作为一种概念验证，用于检测两种不同类型的乳腺癌细胞。根据实验结果，观察到共振吸收峰的幅度和蓝移具有识别和区分不同类型癌细胞的能力。本研究提出了一种开发具有高集成度、高灵敏度和快速无标记检测能力的微流控太赫兹超表面生物传感器的新方法。
