基于“热点”增强定向表面等离子体耦合发射的生物传感新方法

To the fluorescence analysis scientists, how to face the dramatically increased requirements on the sensitive detection of bio-analytes with low concentration, from the areas of biomedicine, genetic engineering and clinical diagnosis, has become a hard and urgent mission. Surface plasmon coupled emission (SPCE) presents directional and polarized radiation. The very recent researches report that the hot-spot induced by metallic film coupled nanoparticle shows remarkable fluorescence enhancement (enhancement factor up to four orders of magnitude). This project will combine hot-spot enhancement and SPCE in a smart way. It is devoted to the development of a new fluorescence enhancement approach applicable to biosensing analysis. The interaction between hot-spot enhancement and SPCE effect will be explored, and the advantageous properties to synergistically improve sensing capacity will be investigated. The relationships between plasmonic property, fluorescence property and enhancement ability will be investigated through the modulation of nanoparticle, SPCE substrate, hot-spot gap and coupling mode. And the biosensing platform with highly efficient coupling will be built up, which is specially based on the biomolecular properties. The sensitivity and the stability of the biosensors will be further improved, utilizing the surface/interface characteristics of the metallic nano-materials to develop new sensing strategies including plasmonic post-enhancement and amplified interface modulation. This project will contribute to the development of highly sensitive surface enhanced fluorescence analysis.

如何应对日益增多的来自生物医学、基因工程、临床诊断等领域对低浓度生物分析物高灵敏的检测需求，已成为荧光分析工作者急需面对的艰巨任务。表面等离子体耦合发射(SPCE)具有定向和偏振发射的传感特性。最新研究发现金属纳米颗粒与薄膜产生的“热点”结构表现出惊人的荧光增强效应（增强倍数高达四个数量级）。本项目巧妙地将“热点”增强效应与SPCE结合，旨在发展适于生物传感分析的增强荧光新方法。考察“热点”增强效应与SPCE的相互影响，协同提高传感分析的优势性能；通过对纳米颗粒、SPCE基底、“热点”间隙及耦合模式的调控，研究表面等离子体特性、荧光特性与增强性能间的关系，针对生物分子特质，构建适用于生物分析的高效耦合传感平台；利用金属纳米材料的表/界面特性，发展表面等离子体“后增强”和界面调控效应放大的传感新策略，进一步提升传感器的稳定性和灵敏度。本项目将为发展高灵敏表面增强荧光分析技术做出贡献。

表面等离子体耦合发射(SPCE)具有定向和偏振发射的传感特性，与纳米结构与材料结合表现出独特的界面分析和传感优势。本项目着重研究金属薄膜表界面特性对表面荧光信号的影响，通过对基底、修饰材料、纳米结构及及耦合模式的调控，研究表界面特性及其对荧光信号的影响，探索界面信号调控与分析的新方法。构建适用于生物分析的高效耦合传感平台，进一步提升界面传感器的稳定性和灵敏度。