双曲超表面等离子体特性及其在高灵敏度SPR生物传感器中的应用

Surface plasmon resonance (SPR) biosensor is expected to solve the bottleneck of traditional optical biosensor due to characteristics with the real-time monitoring, label-free, high sensitivity, and without background interference. However, traditional SPR biosensors have been greatly restricted in terms of integration, sensitivity and detection accuracy in order to realize the detection of biological small molecules and the daily diagnosis of diseases. The performance of hyperbolic metamaterials has far exceeded the SPR biosensor due to their unique dispersion characteristics. However, it is difficult to be practical due to the complexity of structure processing and the large loss in the high frequency band. In this project, a biosensor scheme based on hyperbolic metasurface is proposed, which not only keeps the characteristic properties of hyperbolic metamaterials, but also can solve the problems such as the complexity of structure processing and the large loss. We want to utilize the hyperbolic two-dimensional materials to realize the hyperbolic metasurface with the novel optical properties, and explore the new method to realize the high sensitivity of the biosensor. We hope to build a number of new optical biosensors, resolve the contradiction between the sensitivity and the detection range, the sensitivity and detectability in the current technology, and provide the theoretical foundations and technical supports for the improvement of the comprehensive performance of ultrahigh sensitivity biosensor.

表面等离激元共振（SPR）生物传感器具有实时监测、无标记、高灵敏度、无背景干扰等特点，有望解决传统光学生化传感器件的瓶颈问题。然而，为了实现对生物小分子的检测和疾病的日常诊断，传统SPR生物传感器在集成化、灵敏度和探测精度等方面受到了极大的限制。双曲超材料凭借其特有的色散特性，作为传感器的性能已远远超越了SPR传感器，但由于结构加工复杂、高频段损耗较大等，很难实用化。本课题提出基于双曲超表面的生物传感器方案，不仅保持了双曲超材料传感器特有的性质，还有望能解决加工和损耗等问题。我们希望利用具有双曲色散特性的二维材料，实现具有新奇光学特性的双曲超表面，并探索把双曲超表面SPR应用到高灵敏度生物传感器中的新方法，构建若干新型光学生物传感器件，解决目前技术中灵敏度与检测范围、灵敏度与可检测性之间的矛盾，为实现超灵敏生物传感器件综合性能的提升提供理论基础和技术支持。

本项目对双曲超材料的设计、自然双曲材料构成的可调谐结构、及hBN面内、面外双曲声子极化激元耦合开展了一系列的研究。通过设计BP与金薄膜构成的间层多层结构，得到具有双轴双曲特性的超材料。利用天然双曲材料hBN中的双曲声子极化激元，设计了与VO2共同组成的SPP-SPhPs协调控制体系，提出三种运用二维材料增强SPR生物传感器灵敏度的可靠方案，并进行了实验研究，最后将这种传感芯片用于不同浓度的铅离子检测。在传统的SPR传感器对铅离子低检测灵敏度的基础上，所提出的传感器的铅离子检测灵敏度能够提高六倍。因此，这种传感器可以用于微量的重金属离子检测，具有高灵敏微量检测的优点。