带隙可调的柔性光子纳米链及其阵列传感器的构建与性能

Due to the advantages of the small size, highly sensitivity and fast response rate to external stimuli, as well as the good reversibility, individual one-dimensional magnetic photonic nanochains (referred to as photonic nanochains) promise the important application in the micro-/nano-sensing field. Considering that for the so far developed photonic nanochains, the lattice parameters and photonic bandgap can not be regulated by external stimuli, this project proposes flexible photonic nanochains with photonic bandgaps adjustable by external stimuli, which are constructed based on superparamagnetic colloidal nanocrystal cluster particles and responsive polymers in a nanometer scale, as well as their based array sensors. Taking the magnetic photonic nanochains based on the polymers responsive to temperature, pH value and solutes as examples, their preparation methods and structure control principles will be emphatically investigated. The two aspects of numerical simulation and experimental validation will also be used to clearly illustrate the structure dependency of the orientation behavior under the application of external magnetic field, the photonic bandgap as well as the photonic bandgap response characteristics to external fields (including the response rate and range, sensitivity, reversibility, circulation service life etc.). On the basis of the above research results, photonic nanochain array sensors will also be fabricated by integrating a variety of photonic nanochains which can respond to different stimuli. The real-time fast sensing properties of the array sensors will be studied to the various external stimuli including the pH value, temperature, glucose and metal ions in analytes. The research results obtained in this project are expected to lay a scientific foundation, which may promote the practical application of magnetic response photonic crystals in the micro-/nanosensing area and the development of intelligent color-changing photonic crystal materials.

一维链状磁性光子晶体结构单元(简称光子纳米链)有尺寸小、对外场敏感，响应快、可逆性好等优点，在微纳米检测传感领域有重要应用潜力。本项目针对目前的光子纳米链晶格参数和光子带隙不能通过外场进行调控的弊端，提出利用超顺磁胶体纳米晶簇粒子和响应性聚合物在纳米尺度上复合制备光子带隙可调的柔性光子纳米链及其阵列传感器。以对温度、pH值、溶质分子和离子响应的聚合物基磁性光子纳米链为例，重点研究它们的制备方法与结构控制原理；从数值模拟和实验验证两个方面阐明它们在外加磁场下的取向行为、光子带隙和光子带隙对外场的响应特性(包括响应速率和范围、灵敏度、可逆性、循环使用寿命等)与其结构的依赖性关系；并将对不同外场响应的光子纳米链集成加工成光子纳米链阵列传感器，研究其对分析物的温度、pH值、和溶质等的实时快速传感能力。项目研究成果能为推动磁性光子晶体实际应用于微环境、痕量检测传感，和研制智能变色材料奠定科学基础。

响应性光子纳米链是响应性光子晶体的最小结构单元，其一维链状结构由响应性凝胶包覆且壳层厚度仅有几十纳米。每一根光子纳米链即为一个独立的对外场响应的像素点，这使得其颜色分辨率和外场响应速度明显优于现有微球或膜状光子晶体传感器。此外，响应性光子晶体纳米链组成、结构参数、软硬度等的改变会引起其外场下光子带隙、取向结构的变化，这赋予其光学性能在可见光谱范围内的丰富可调，因而较传统响应性光子晶体和非响应性光子纳米链在彩色显示、光子纸、传感、防伪等领域拥有更广阔的应用前景。.本项目针对以无机材料为壳层的光子纳米链晶格参数和光子带隙不能通过外场进行调控的弊端，开展了利用超顺磁胶体纳米晶簇粒子Fe3O4@PVP和响应性聚合物在纳米尺度上复合制备光子带隙可调的柔性光子纳米链及其阵列传感器的研究。我们通过在磁性组装粒子PVP壳层与响应性聚合物单体间构建氢键相互作用，发展了基于氢键诱导模板法的响应性光子纳米链的制备技术，先后制备了pH、温度、葡萄糖等响应的磁性光子纳米链。pH响应性光子纳米链的性能研究表明光子纳米链的颜色分辨率以及响应速度较传统光子晶体提高了2~3量级；通过温敏响应性光子纳米链的研究发现响应性光子晶体纳米链为柔性链，随着外加磁场强度的增加反射率单调增加而衍射波长不变；我们通过光学显微镜观察和数值模拟相结合的分析方法，阐明了磁场下柔性光子纳米链的取向演变过程对光学性能的影响。温敏响应性光子纳米链表现出温磁双响应型，其衍射波长与衍射峰位可以通过不同外场进行分别调控，实现了亮度和颜色的独立操控。葡萄糖响应性光子晶体纳米链的制备使得对葡萄糖的响应能力提高到秒级，有利于葡萄糖的快速检测。此外，基于pH响应性光子纳米链阵列传感器实现了对分析物的快速、原位、痕迹量检测，是一类适用于微环境原位检测的传感器。本项目在阐明响应性光子纳米链结构、取向性等对其光学性能和外场响应性的基础上，开发了基于响应性光子纳米链的光子晶体纸和存储标签，该光子晶体纸兼具磁-擦写和温场控制下的显示-隐藏功能；同时我们基于RGB原理，开展了借助不同颜色的光子纳米链构筑多光子带隙从而实现亮丽混合色的调制。.综上，本项目的研究成果对发展灵敏响应的微型光子晶体传感器和构筑多功能新型光子晶体显示材料有重要理论指导意义，为响应性光子晶体在多领域的实际应用奠定基础。