三维有序Au纳米颗粒/智能水凝胶微胶囊的制备及其可视化生物传感特性研究

Planar colloidal crystal sensors has disadvantages of low response rate and week optical response, in order to resolve this problem, we present a new idea of combination of the three-dimensional (3D) spherical microcapsule of Au nanoparticles with the smart responsive hydrogel, and use the interfacial self-assembly technique and the light-induced polyermerization strategy, to in situ composite the smart hydrogel polymer into the Au microcapsule structures, constituting the new optical biosensor devices. We will systematically study the influence of ordering structure and optical properties of microcapsule on the law of diffraction wavelengths, and investigate their applications in visual biosensor detection. The motivation of this project is to develop the constitution method of the 3D ordered Au microcapsule/smart responsive hydrogel biosensors with high diffraction intensity and high response rate performance, and to reveal the dependence of visually evident sensing technology on optical diffraction of microcapsule. This study will not only provide design ideas and realization route for the high diffraction intensity and high response biosensors, and the material base and practical application in the recent years for 3D metal microcapsule in visually evident biosensor devices, but also is of importance to reveal the composite process, optical diffraction enhancement mechanism and bio-sensing mechanism of Au microcapsule/smart responsive hydrogel structures.

本项目针对平面型胶体晶体/水凝胶生物传感体系的响应速率低、光学响应弱，提出将Au纳米颗粒的三维（3D）球形有序微胶囊与智能水凝胶相复合的思路，采用基于界面自组装和光诱导聚合的构建策略，在有序Au微胶囊结构上原位复合智能水凝胶聚合物，构成新型的光学生物传感器件；系统研究有序Au微胶囊中有序结构和光学特性对光衍射规律的影响，探索其在可视化传感方面的应用等。旨在发展基于3D有序Au纳米颗粒/智能水凝胶微胶囊的生物传感器件的构建方法，实现高响应速率、高衍射强度传感器件的构筑，揭示Au微胶囊/智能水凝胶体系的光衍射规律与可视化生物传感特性之间的关联。这不仅可为高衍射强度、高响应速率可视化生物传感器的设计与研制提供设计思想与实现途径，为金属3D微胶囊结构在可视化生物传感器件的实用化提供材料基础与近期可实现性；而且对揭示这类新型智能水凝胶微胶囊的复合过程、光衍射增强机理及其传感特性机制也具有科学意义。

针对现有基于胶体晶体与智能水凝胶复合的生物传感器件，普遍存在响应速度慢、颜色可辨别弱等问题，我们提出了将具有超高散射截面的金纳米颗粒为基本构筑单元，采用低成本的界面自组装技术，构筑出多样的金纳米颗粒有序体。随后，通过快速的光诱导聚合技术，将该金纳米颗粒有序体与智能水凝胶体系复合，构筑出新一代的光学生物传感器件。其工作原理主要是利用依赖金纳米颗粒间的等离子激元耦合峰位移设计而成。具体表现为：基于水凝胶薄膜的定量体积溶胀，驱使该器件中的有序多聚体的颗粒间间隙的可控变化，进而实现其耦合峰峰位的有效位移调控，宏观表现出不同颜色的变化，且该颜色变化不具有角度依赖性；同时，通过建立起耦合峰位移量与目标分析物的浓度的变化关系，实现不同溶度的可视化检测。进一步，通过简单控制水凝胶的交联度程度，实现了器件灵敏度的调控，从而展现出超宽的动态调谐灵敏度范围。该器件表现出超强的颜色可分辨能力（肉眼清晰可辨别），响应速度快，稳定性强，为下一代可视化生物传感器件的设计与研制提供了设计思路与途径。