【作者】 赵峰；

【导师】 吴朝阳；

【作者基本信息】 湖南大学 ， 化学， 2023， 硕士

【摘要】 光子晶体作为一种具有光子禁带的周期性介电材料,可以对光传播起到调控作用,从而产生不同于传统色素颜色的明亮结构色。随着光子晶体材料的不断深入研究,具有特殊光学信号的响应型光子晶体在分析传感、防伪加密、生物医学、光催化等领域被广泛关注。目前,对于目标物进行检测分析的常用方法有:电感耦合等离子体质谱法、表面增强拉曼散射、原子吸收法光谱法等,但这些检测方法一般都需要依赖昂贵复杂的仪器设备,且检测时间较长、需要专业的科研人员操作。基于优良光学特性的优势,响应型光子晶体可被应用于分析传感领域的研究,为开发简单便携、可视化分析的新型检测方法提供了新的路径。本文以单分散性核壳纳米粒子为组装基元,利用光子晶体在光信号转换方面的特殊优势,结合功能性水凝胶,制备了两种简单可视化的传感器用于铀酰离子、葡萄糖的灵敏检测。主要研究内容如下:（1）在第二章中,制备了一种可视化检测UO₂²⁺的低角度依赖性光子晶体水凝胶材料。通过化学水浴沉淀法和St?ber法制备具有核壳结构的高折射率ZnS@SiO₂纳米粒子,通过调控单体及TEOS的含量来控制核壳纳米粒子的粒径。通过垂直沉积法将ZnS@SiO₂乙醇溶液制备成低角度依赖性的光子晶体薄膜,再与功能性丙烯酰胺水凝胶相结合来构建光子晶体水凝胶。由于水凝胶网络的配位基团会与UO₂²⁺结合作用,光子晶体水凝胶交联度增加引起体积收缩,从而减小ZnS@SiO₂纳米颗粒间的间距,反射峰波长蓝移,水凝胶的结构色会发生相应变化,从而实现对UO₂²⁺的定性定量分析。该传感器对UO₂²⁺的最低检测限为1 n M,对样品检测具有良好的选择性和再生性能。此外,相比于传统的低折射率光子晶体,ZnS@SiO₂光子晶体水凝胶具有低角度依赖性,可以减少在不同视角下肉眼检测带来的干扰,响应信号分析更为准确。同时,该光子晶体传感器实现了实际水样中UO₂²⁺的可视化检测。（2）在第三章中,以超顺磁性纳米粒子为组装基元,制备了一种可对葡萄糖响应的一维磁响应光子晶体水凝胶。通过溶剂热法和St?ber法制备具有核壳结构的超顺磁性Fe₃O₄@SiO₂纳米粒子,通过控制水以及TEOS的量来调控核壳纳米粒子的粒径。将Fe₃O₄@SiO₂与丙烯酰胺、3-丙烯酰胺基苯硼酸功能性水凝胶相结合,在磁场的作用下超顺磁性纳米粒子自组装成一维有序链状结构,调控磁场强度可以呈现出不同的结构色,通过紫外聚合制备成光子晶体水凝胶。利用葡萄糖与苯硼酸响应形成双齿络合物,使得水凝胶的交联度增大,引起水凝胶体积收缩,改变Fe₃O₄@SiO₂粒子间的间距,使反射峰波长向短波方向移动,成功实现对葡萄糖的检测。在1 m M至10 m M的葡萄糖浓度范围内,该光子晶体传感器反射峰的位移值与葡萄糖浓度呈现较好的线性关系,R²的值为0.9939。此外,该传感器还具有良好的选择响应性、抗干扰性以及可再生性,有望成为一种检测葡萄糖的简单便携工具。更多还原

【Abstract】 As a kind of periodic dielectric material,photonic crystal has photonic band gap,which can play a role in regulating light propagation,thus producing a bright structural color different from traditional pigments.In recent years,with the continuous in-depth research of photonic crystal materials,responsive photonic crystals with special optical signals have been widely concerned in the fields of anti-counterfeit encryption,analysis and sensing,biomedicine,photocatalysis and so on.At present,the common methods used for detecting target include inductively coupled plasma mass spectrometry（ICP-MS）,surface-enhanced Raman scattering（SERS）,atomic absorption spectrometry（AAS）,etc.However,these methods usually are dependent on expensive and complex instruments and equipment,take a long time to detect,and require professional scientific researchers to operate.Therefore,based on excellent optical properties,responsive photonic crystals can be applied to research in the field of analysis and sensing,providing a new path for the development of simple,portable and visual analysis of new detection methods.In this paper,based on core-shell nanoparticles as the assembly unit,using the special advantages of photonic crystals in light signal conversion,combined with functional hydrogels,two simple visual sensors are prepared for sensitive detection of uranyl ions and glucose,which can be applied to certain practical scenes.The main research contents are as follows:（1）In the second chapter,a low angle dependent photonic crystal hydrogel sensor for visual detection of UO₂²⁺was fabricated.By chemical water bath precipitation and St?ber method,ZnS@SiO₂ was successfully prepared,with core-shell structure and high refractive index.The size of core-shell nanoparticle was controlled by adjusting the ratio of monomers and the volume of TEOS.A low angle dependent photonic crystal film was vertically deposited,and then combined with functional acrylamide hydrogel to construct photonic crystal hydrogel.Because uranyl ions can complex with the coordination groups on the hydrogel skeleton,the photonic crystal hydrogel shrinks,thus reducing the spacing between ZnS@SiO₂ nanoparticles.The wavelength of the reflection peak shifts towards the shorter wavelength direction.And the structure color of the hydrogel will change accordingly.The minimum detection limit of the sensor for uranyl ions is 1 n M.The photonic crystal hydrogel has good selectivity,regeneration performance and anti-interference performance for sample detection.In addition,compared with traditional low refractive index photonic crystals,ZnS@SiO₂ photonic crystal hydrogel has low angle dependence,which can reduce the interference caused by visual inspection at different angles.And the response signal is more stable.The photonic crystal sensor can be used for visual detection of uranyl ions in actual water samples.（2）In the third chapter,a kind of one-dimensional magnetic responsive photonic crystal hydrogel was prepared with superparamagnetic nanoparticles as the assembly unit.The superparamagnetic nanoparticle Fe₃O₄@SiO₂with core-shell structure was prepared by solvothermal method and St?ber method.The size of nanoparticle can be adjusted by controlling the water content and the volume of TEOS.Fe₃O₄@SiO₂ and the functional hydrogels of 3-acrylamidoaminophenylboronic acid and acrylamide were combined to form a one-dimensional ordered nano chain structure under the action of magnetic field.By adjusting the intensity of magnetic field,photonic crystal hydrogels with different structural colors were prepared.The reaction of glucose and phenylboronic acid forms a bidentate complex,which increases the degree of crosslinking,thus causing the volume contraction of the hydrogel and changing the spacing between the magnetic colloidal particles.The wavelength of the reflection peak shifts towards the shorter wavelength direction,and the photonic crystal hydrogel realizes the detection of glucose.In the range of glucose concentration from 1 m M to10 m M,the diffraction shift value of reflection peak has a good linear relationship with glucose concentration,and the value of R² is 0.9939.Besides,the sensor has good selective response,anti-interference and reproducibility.And the sensor has the potential to be a simple and portable tool for glucose detection.更多还原