基于石墨烯双曲超材料的高灵敏太赫兹生物传感研究

Terahertz (THz) biosensing based on metamaterials has the advantages of label-free and high sensitivity, which can be used for detecting trace samples efficiently. But the detection limit still needs to be further improved. In the visible and near-infrared band, the record-breaking sensitivity and figure of merit have been achieved based on hyperbolic metamaterials. However, there is hardly any report about the THz biosensing based on hyperbolic metamaterials. The proposed project intends to establish a highly sensitivity THz biosensing method based on graphene hyperbolic metamaterials. Graphene has low loss and high biocompatibility. The hyperbolic dispersion characteristics can be achieved by using graphene/dielectric multilayer structure in the THz band. We will focus on the sensing performance of two graphene hyperbolic metamaterials structures, one is graphene/dielectric multilayer array and the other is two-dimensional metal grating coupled graphene/dielectric multilayer. Firstly, the sensing mechanism and characteristics based on graphene hyperbolic metamaterials in the THz range will be clarified. The influence of material and structural properties on the sensing performance will be established to optimize the device design and explore the sensing performance limit. Then, based on the three-dimensional multi-layer structure and electric field enhancement depth of hyperbolic metamaterials, the microfluidic technology will be introduced by setting the sensing region highly overlapped with the electric field enhancement region. The high-performance sensing of trace biological samples will be realized based on the proposed microfluidic graphene hyperbolic metamaterials design. The realization of proposed project is of positive significance to promote the application of THz technology in the biomedical field.

基于超材料的太赫兹生物传感具有高灵敏和无标记等优点，可实现微量样品高效检测，但其探测极限仍有待进一步提高。金属双曲超材料在可见光和近红外波段的生物传感实现了破纪录的灵敏度和评价因子，但双曲超材料在太赫兹波段的生物传感研究还鲜有报道。本项目拟建立基于石墨烯双曲超材料的高灵敏太赫兹生物传感方法，石墨烯损耗低和生物相容性高，可利用石墨烯/介质多层结构在太赫兹波段实现双曲色散特性，拟设计阵列式石墨烯/介质多层双曲超材料和二维金属光栅耦合石墨烯/介质多层双曲超材料两种结构，重点关注其生物传感性能。首先明晰石墨烯双曲超材料在太赫兹波段的传感机制，揭示材料和结构属性对传感性能的影响，优化器件设计和探究传感性能极限；并基于双曲超材料的多层立体结构和电场增强深度，结合微流控技术，设计传感区域与电场增强区域高度重叠，实现微量生物样品的高性能检测。本项目的实施对于推动太赫兹技术在生物医学领域的应用具有积极意义。

太赫兹超材料生物传感具有高灵敏、无标记、响应快等优点。本项目基于石墨烯双曲超材料进行太赫兹生物传感研究。首先，基于光泵浦、电调制和太赫兹探测等方法，对石墨烯材料和结构在太赫兹波段的超快载流子和吸收特性进行了研究，明晰石墨烯材料和结构的太赫兹性质。对石墨烯双曲超材料在太赫兹波段的双曲色散、共振响应和局域场增强特性进行了系统研究，分析比较了石墨烯层数和费米能级、介质层材料、阵列结构、二维金属光栅耦合结构等的影响，并研究了生物检测物分布和折射率变化对超材料传感性能的影响。在超材料局域场增强敏感区域设置微流沟道，研究了微流沟道与场增强区域重叠分布、材料和流通方式等的影响，选择高效的超材料器件结构和材料。基于超材料传感器，对微量的牛血清蛋白、肿瘤标记蛋白等典型生物大分子样品进行了高灵敏传感检测，并提出了靶向抗体修饰和金属纳米颗粒增敏方法，揭示了金属纳米颗粒增敏效果的粒径依赖性。针对超材料生物传感对太赫兹波谱检测系统和信号分析方法的高要求，研发了多种强太赫兹源和高灵敏探测器，搭建了高性能生物传感检测系统；提出了多种太赫兹波谱传感信号降噪、分析和自动分类识别方法，成功应用于生物组织等样品的自动诊断；并对液态水等液体的超快分子间氢键动力学进行了高灵敏传感测量和分析。本项目对于推动太赫兹检测技术发展及其生物医学应用具有积极意义。.基于项目资助，共发表SCI期刊论文19篇（JCR一区论文12篇），学术会议论文5篇。申请国家发明12项（授权3项），实用新型专利3项（授权2项）。项目组成员参加领域国内外顶尖学术会议3次，作邀请/口头报告5次，海报展示2次。