面向微流控光学传感的管状微腔内通道微纳构筑

Tubular whispering-gallery microcavities, with hollow core structure which can serve as microchannels for chemical and biological microfluids and are also integratable with microfluidic devices, have received increasing interest in label-free optofluidic sensing. However, due to the concealed location and tiny size, it is always with difficulty to realize the controllable, precise and functional construction of the inner micro-channel for higher sensitivity and lower detection limit in optofluidic sensing. Besides, it is with high importance to make connection between the optical response and the label-free targets for multiple sensing mechanisms in label-free optofluidic sensing, by making full use of the complex information in the optical resonance, such as resonant wavelength, intensity, linewidth, together with the correlated principles in physics, chemistry and biology. In this context, rolled-up microtubular cavities with inner plasmonic micro/nanostructures will be fabricated in this project. The material and structural parameters will be optimized to support efficient hybrid photon-plasmon modes in the inner micro-channel. The physical mechanism of the origin of the hybrid modes will also be investigated for enhancing the optofluidic sensing performance. Moreover, the multiple sensing mechanisms for detecting label-free targets will be built. Finally, the cavities will be integrated with optofluidic devices for sensing applications.

管状回音壁微腔的内部空心结构可为化学、生物微流体提供流通管道，同时易于与微流控器件耦合集成，近年来在无标记微流控光学传感领域得到了广泛的关注。然而由于微管内通道位置隐蔽且尺寸微小，对其进行可控、精确、功能化的微纳构筑，从而实现更高灵敏度和更低检出限的微流控光学传感检测一直是该领域的难点。另外，如何充分利用光学共振模式所传达的信息（如波长、强度、峰宽等），并结合物理、化学、生物等领域相关原理，构建光学响应与无标记待检物之间的联络，从而获得多方位的微流体无标记分析检测光学传感机理，这也是光学检测领域的研究热点之一。对此，本项目将从理论和实验两方面入手，构筑管状微腔内通道的表面等离激元金属微纳结构，揭示光-表面等离激元杂化模式的产生机制，解决金属微纳结构修饰下的薄膜自卷曲问题，实现管状微腔内通道微纳构筑，构建微流体无标记分析检测的光学传感机理，最终实现与微流控光学传感系统的集成与应用。

在本项目研究中，采用卷曲纳米薄膜技术结合微纳加工手段，解决了金属微纳结构修饰下的薄膜自卷曲问题，实现了对管状微腔内通道进行可控、精确、功能化的微纳构筑，制备了贵金属表面等离激元微纳结构复合的微管状回音壁谐振腔。揭示了微腔中光-表面等离激元杂化模式的产生机制，对其谐振模式进行调控，优化其品质因子和模式体积。同时构建微流体无标记分析检测的光学传感机理，使管状微腔适用于稳定性好、灵敏度高、检测限低的微流控光学传感，并实现与微流控光学系统的片上集成与应用。在项目支持下取得了系列重要的创新成果，圆满完成了研究计划和预期目标，发表SCI收录论文6篇，包括Nano Letters, ACS Nano, Advanced Energy Materials, Advanced Optical Materials等国际顶级期刊，申请国内专利1项，培养研究生4名。