Goos-Hanchen效应耦合表面等离子体共振生物传感器

In this project, a novel sensor device will be developed based on surface plasmon resonance (SPR) coupled to Goos-Hanchen (GH) effect, which allows the enhancement and direct measurement of GH shift. The optical and mechanical parts are integrated into a compact structure and embedded in a light and water proof enclosure to form a modular device. Single laser light source is used to produce both the sensing and reference beams with p- and s- polarization, respectively. Power of the light beams is stabilized using non-disrupting polarization switching mechanism based on a pair of synchronized optical choppers. GH shift is coupled to the SPR excited by the p-polarized beam, and amplified optically by precisely controlled multiple reflection. The signal quality and reliability are enhanced by using the novel data acquisition algorithm based on 4-channel lock-in amplification. As the novel key sensing device, this sensor will provide a new option for sensitive chemical and biochemical analysis. Oligonucleotide probes having specific interactions with heavy metal ions will be designed and used to modify the GH-SPR sensor surface for heavy metal detection. Gold nanoparticles will be used for enhancement of GH-SPR signal. The binding and competition mechanism among heavy metal ions, oligonucleotide probes and gold nanoparticles will be studied. The sensing methods are designed in such a way that immobilized oligonucleotide probes are reusable. The GH-SPR biosensor device together with oligonucleotide probes will allow rapid and low-cost monitoring of heavy metal ions with resistance to interference from environment. There will be great potential of on-site real-time applications of the biosensor system in water, food, agricultural, environmental and biomedical industries.

本项目将研究一种增强并实现了直接测量Goos-Hanchen（GH）位移的GH效应耦合表面等离子体共振生物传感器，模块化设计整合了光学、机械和电子部件，仅用一个激光光源同时产生p-和s-偏振光束分别用于测量和参比，用一对同步光断续器实现非中断偏振切换机制以获得稳定的光信号。GH位移与被p-光束激发的SPR耦合放大，通过精确设计的多重反射等光学方法获得扩大。四通道锁相放大技术用于数据采集和处理提高了信号质量和可靠性。该传感器可做为关键部件为灵敏的化学和生化分析提供新途径。以寡核苷酸探针(ONP)与重金属离子的特异性相互作用为检测方法，并用金纳米粒子进行信号增强，同时研究三者之间的相互作用与竞争机理以及ONP的重复使用。由GH-SPR和ONP组成的生物传感器系统可实现低成本、现场、实时和抗环境干扰的重金属检测，将在水、食品、农业、环境和生物医学等领域中有很好的应用前景。

项目执行期为2015-2017年，共三年，使用经费25万元，全部按计划执行。项目执行过程中完善了相关基础设施和核心实验设备，重点开发一套基于Goos-Hanchen效应耦合表面等离子共振的生物传感器(GH-SPR)。对Goos-Hanchen效应与SPR的耦合过程中的信号增强作用进行了研究，构建并整合了GH-SPR传感器的光学、机械部件与电子电路，同时，开发适合GH-SPR传感器的高灵敏度和特异性DNA 探针涂层，形成了一个高稳定性、高分辨率的紧凑闭合型模块化的，用于微量、痕量物质检测的GH-SPR生物传感器系统，完成了预期目标。项目发表论文4篇，已接受待发表1篇，其中SCI论文3篇，EI论文1篇。其中一篇论文获得2016年ENI国际环境奖提名。申请发明专利3项。.通过传感器光路优化，简化双光路激光光源的交替开关设计，采用独特设计的光斩波器使两条光线交替通过，省去了复杂的激光驱动器，也减少了激光高频开关引起的光强度不稳定的问题。设计了紧凑型机械构件，排除环境和光源不稳定性对信号的干扰，使用3D打印技术进行快速试验和优化修改，并进行了组装测试。制作了基于微处理器的控制与数据采集电路版，通过四通道数字式锁相放大器对四路光信号分别处理运算，减少光强度波动对测量信号的影响。开发了仪器控制与数据处理软件操作界面，具备仪器操作、校准和数据采集等商用分析仪器的基本功能。.设计可重复使用的DNA探针，优化其在SPR传感器金膜表面的修饰效果，利用DNA探针与重金属离子的特异性相互作用实现对重金属离子的检测和信号放大。对Hg2+和Pb2+离子有特异性的带有-SH基团的DNA酶与DNA探针，传感器的信号强度变化与离子浓度在纳摩尔范围呈正相关，并且在有10倍浓度的Zn2+, Co2+, Cd2+, Mg2+, Cu2+, Ni2+, Fe2+,和Ba2+等干扰离子同时存在的条件下保持良好的检测效果。