Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.
Department of Oncology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.
ACS Sens. 2021 May 28;6(5):1884-1890. doi: 10.1021/acssensors.1c00174. Epub 2021 May 12.
Metamaterial-inspired terahertz (THz) biosensors are devoted to developing high-sensitivity and label-free biosensing strategies. However, most meaningful molecular signals are obscured by the strong THz absorption of solvent water. Most reported THz biosensors require the tested samples to be tediously dried or replaced with a low-absorption medium, which impairs the original bioactivity and the distribution homogeneity of targets. As described in this proposed strategy, a molecule-specific THz biosensor was fabricated from an aptamer hydrogel-functionalized THz metamaterial. Benefitting from the strong interaction with the localized electric field of the metamaterial, trace thrombin-induced variations in the hydration state of the hydrogel can be sensitively probed, which was investigated experimentally and theoretically. The optimized THz biosensor exhibited remarkable specificity for actual serum sample assays and excellent sensitivity, with a relatively low detection limit of 0.40 pM in the human serum matrix. The proposed strategy could serve as a model system to develop various molecule-specific THz biosensors for aqueous molecule sensing.
基于超材料的太赫兹（THz）生物传感器致力于开发高灵敏度和无标记的生物传感策略。然而，大多数有意义的分子信号被溶剂水的强 THz 吸收所掩盖。大多数报道的 THz 生物传感器需要将测试样本繁琐地干燥或更换为低吸收介质，这会损害目标的原始生物活性和分布均一性。在本研究提出的策略中，一种基于适体水凝胶功能化太赫兹超材料的分子特异性太赫兹生物传感器被制备出来。受益于与超材料局域电场的强相互作用，痕量凝血酶诱导的水凝胶水合状态变化可以被灵敏地探测到，这在实验和理论上都得到了研究。优化后的太赫兹生物传感器对实际血清样本分析表现出显著的特异性和优异的灵敏度，在人血清基质中的检测限低至 0.40 pM。该策略可以作为一个模型系统，用于开发用于水溶液分子传感的各种分子特异性太赫兹生物传感器。
