【作者】 李玲；

【导师】 盖方圆；

【作者基本信息】 长春工业大学 ， 化学， 2020， 硕士

【摘要】 众所周知,在人体内定量检测半胱氨酸（Cys）对于健康监测和疾病预测具有重要意义。与各种报道的分析方法相比,荧光法因其测试速度快,成本低,灵敏度高和操作简便而引起了广泛关注。然而,有机荧光探针大多存在荧光量子产率低、耐光漂白能力弱、激发范围窄、在水溶液中溶解性差等缺点。相比较而言,SiO₂交联单胶束纳米粒子（SCMNPs）具有优良的介观结构疏水核,可用更多的有机和医学物质进行多功能化,用于体内在线监测和治疗。因此,设计和合成具有超小尺寸的SiO₂基纳米传感器是至关重要的。本文以F127三嵌段共聚物为模板,分别采用正硅酸乙酯（TEOS）、仲丁醇铝（ASB）掺杂的TEOS为前体,合成了SCMNPs。考察了荧光SCMNPs在Cys检测方面的应用以及ASB掺杂的SCMNPs本身的优异特性。具体内容如下:1.将三种有机染料（荧光素衍生物（FCD）、香豆素衍生物（HCE）和罗丹明B（RhB））包覆在SCMNPs的疏水核中。设计和合成了多种染料掺杂的SCMNPs（MD-SCMNPs）,以实现水介质和活细胞中Cys的荧光传感。在MD-SCMNPs的核心处,FCD与Cys反应产生绿色发光传感产物,这一绿色发光传感产物可能引起从HCE到传感产物再到RhB的“逐级”荧光共振能量转移（FRET）。基于疏水核中的FRET过程,MD-SCMNPs可以通过肉眼可见的颜色变化定量检测活细胞中的Cys,检测限（LOD）为0.3μM。此外,MD-SCMNPs具有超小尺寸（¹2 nm）,良好的分散性和生物相容性,可作为人体健康监测和疾病预测的可视化Cys传感器。2.将ASB掺入SiO₂骨架中,通过一种新的凝胶骨架增强法,设计和合成了疏水内核环境改变的SCMNPs。我们发现溶胀剂均三甲苯（TMB）的含量对不同硅铝体积比合成的硅铝杂化单胶束纳米粒子粒径有一定的影响。随后,将该杂化纳米粒子进行煅烧,获得了具有超大比表面积的介孔材料。所获得的硅铝杂化单胶束纳米粒子具有超小粒径（¹0 nm）、超大BET比表面积（1186.64 m²/g）、热稳定性好、形貌均匀、分散性好、原料廉价易得、合成简单等优势。该粒子的超小粒径明显低于肾清除阈值,使其有望成为一种新的纳米载体。此外,这种多孔纳米粒子的超大BET比表面积使得它在气体吸附与分离领域具有潜在的应用价值。值得一提的是,硅铝杂化壳层改变了疏水内核中有机染料周围的环境,这对于增强有机染料的荧光量子产率具有极大的意义。更多还原

【Abstract】 It is well known that the quantitative detection of cysteine（Cys）in the human body is of great significance for health monitoring and disease prediction.Compared with various reported analytical methods,fluorescent methods have attracted much more attention due to its fast test speed,low cost,high sensitivity and relative operational simplicity.However,most of the organic fluorescent probes exhibited the disadvantages of low fluorescence quantum yield,weak photobleaching resistance,narrow excitation range,and poor solubility in aqueous solutions.In comparison,SiO₂ cross-linked micellar nanoparticles（SCMNPs）possessed excellent mesostructured hydrophobic cores,which can be multi-functionalized with more organic and medical substances for online monitoring and in vivo treatment.Therefore,the design and synthesis of SiO₂-based nano-sensors with ultra-small size is critical.In this paper,SCMNPs were synthesized by using F127 triblock copolymer as a template and using tetraethyl-orthosilicate（TEOS）and TEOS doped with aluminum sec-butoxide（ASB）as precursors.The application of fluorescent SCMNPs in Cys detection and the excellent characteristics of ASB-doped SCMNPs themselves were investigated.The details are as follows:1.Three organic dyes（Fluorescein derivative（FCD）,Coumarin derivative（HCE）and Rhodamine B（RhB））were coated in the hydrophobic core of SCMNPs.Multiple dye-doped SCMNPs（MD-SCMNPs）were designed and synthesized to achieve Cys fluorescence sensing in aqueous media and living cells.FCD reacted with Cys and exhibited green fluorescence“turn-on”in the core of MD-SCMNPs.This green-light-emitting sensing product may cause‘‘step by step”fluorescent resonance energy transfer（FRET）from HCE to the sensing product and then to RhB.Based on the FRET process in the core,MD-SCMNPs can quantitatively detect Cys by a colour change with a low limit of detection（LOD）of 0.3 uM in living cells.Furthermore,MD-SCMNPs exhibited ultra-small size（¹2 nm）and excellent dispersity and biocompatibility,which could potentially be used as a visualized Cys sensor for health monitoring and disease prediction in the human body.2.ASB was incorporated into the SiO₂ framework,and a new gel framework enhancement method was used to design and synthesize SCMNPs with a changed hydrophobic core environment.We found the effect of the swelling agent mesitylene（TMB）content on the particle size of silica-alumina hybrid micellar nanoparticles synthesized with different silicon-aluminum volume ratios.Subsequently,the hybrid nanoparticles were calcined to obtain a mesoporous material with a large specific surface area.The obtained silica-alumina hybrid micellar nanoparticles hold ultra-small particle size（¹0 nm）,large BET specific surface area（1186.64 m²/g）,excellent thermal stability,uniform morphology,and superior dispersibility,cheap raw materials,easy synthesis and so on.The ultra-small particle size of the particle is clearly below the renal clearance threshold,making it a promising nanocarrier.In addition,the large BET specific surface area of this porous nanoparticle make it potentially useful in the field of gas adsorption and separation.It is worth mentioning that,the silica-alumina hybrid shell changes the environment around the organic dye in the hydrophobic core,which has great significance for enhancing the fluorescence quantum yield of organic dyes.更多还原