条波导激励可调谐对称微纳结构的准分布式SPR传感机理研究

Surface plasmon resonance (SPR) sensing technology has been widely used in biochemical detection. Effective tunable mechanism and integration multi-point detection are two important open problems for SPR sensors. This project investigates into the quasi distributed SPR sensing mechanism by a symmetrical structure with metal nano holes, dielectric, and metal nano holes excited by the channel waveguide. We also analyze electromagnetic field of micro-nano structure consisting of metal nano holes, dielectric and nano holes implemented by the three-dimensional finite-difference time-domain method. Additionally, we study the influences of metals, lattice and structure parameters of metal nano holes on the resonance peak position, and the sensing sensitivity and the tunable mechanism of adjusting the distance between two layers of nano holes. Furthermore, we reveal the mechanism of double attenuation peaks can be excited by the structure and investigate into the optimization design of the single-mode waveguide. With the above investigation, we propose an experimental method to interpret the effective refractive index distribution of the single-mode channel waveguide, which is designed to excite the micro-nano structure. This micro-nano structure with different conditions in the longitudinal distribution of the waveguides is used to excite the multi-attenuation peaks to realize the multi-point quasi distributed detection. The tunable mechanism provides an effective solution for the constrained range of refractive index detection. The investigations of the formation mechanism of multi-attenuation peaks in this project will provide the theoretical basis and technical support for the development and application of waveguide SPR multi-point quasi distributed sensing technology.

SPR传感技术已成为生化检测的重要手段， SPR传感器的有效调谐及集成化多点检测是亟待解决的重要课题。本项目提出条波导激励金属纳米孔－介质－金属纳米孔的对称结构的准分布式SPR传感机理：采用三维时域有限差分法对金属纳米孔-介质-金属纳米孔的微纳结构进行电磁场分析，解明金属材质、厚度及纳米孔的晶格及结构参数对共振峰位置和传感灵敏度的影响，分析上下两层金属纳米孔膜间的距离，待测介质的折射率与波矢匹配之间的关联机制，揭示该结构可产生双衰减峰的机理；研究单模条波导的优化设计和实验推定离子交换单模条波导折射率分布的方法，设计激励微纳结构的单模条波导；研究将不同参量的对称微纳结构在条波导上纵向分布，形成不交叠的多衰减峰的准分布式传感机理。项目研究的可调谐机制，为解决强度检测时折射率受限提供了有效解决途径，多衰减峰形成机理，为波导型SPR传感器的多点准分布式检测提供理论基础和技术支持。

SPR传感技术已成为生化检测的重要手段，SPR传感器的有效调谐及集成化多点检测是亟待解决的重要课题。本项目提出条波导激励金属－介质－金属的对称结构的准分布式SPR传感机理：采用三维时域有限差分法对对称的膜层结构及微纳结构进行电磁场分析，解明金属材质、厚度及结构参数对共振峰位置和传感灵敏度的影响；分析上下两层金属孔膜间的距离，待测介质的折射率与波矢匹配之间的关联机制，揭示该结构可产生双衰减峰的机理；研究单模条波导的优化设计和实验推定离子交换单模条波导折射率分布的方法，设计激励对称膜层及微纳结构的单模条波导；研究将不同参量的对称膜层及微纳结构在条波导上纵向分布，形成不交叠的多衰减峰的准分布式传感机理。项目研究的可调谐机制，为解决强度检测时折射率受限提供了有效解决途径，而多衰减峰形成机理，为波导型SPR传感器的多点准分布式检测提供理论基础和技术支持。