【作者】 盖方圆；

【导师】 霍启升；

【作者基本信息】 吉林大学 ， 无机化学， 2014， 博士

【摘要】 近年来，无机-有机复合纳米材料的设计和合成越来越多的受到了科学家们的广泛关注。在众多的复合纳米材料中，单胶束二氧化硅纳米粒子作为杂化复合纳米材料的无机部分，具有合成过程简单、尺寸较小、水溶性佳、低毒性以及良好的生物兼容性等特点，在生物传感领域有潜在的应用。本论文用单胶束二氧化硅纳米粒子作为媒介，在其疏水内核中引入荧光有机染料来制备功能化的水溶性复合纳米材料。通过包覆和修饰等过程合成了一系列功能化的单胶束二氧化硅荧光纳米粒子并对其性质和应用进行了研究。主要成果如下：1.研究了单一有机染料掺杂的单胶束二氧化硅荧光纳米粒子的光学性质。在单胶束二氧化硅纳米粒子中掺杂了香豆素衍生物（HCE）蓝光染料。单胶束包覆的香豆素衍生物（HCE-SCMNPs）的荧光发射和紫外吸收相对于相同浓度的HCE有机溶液几乎没有变化。而HCE包覆在单胶束二氧化硅纳米粒子中的荧光寿命却比有机溶液中的有显著增长。而后，测试了HCE在单胶束二氧化硅纳米粒子疏水内核中对pH的响应效果。HCE-SCMNPs能够在水溶液中响应氨水，表明HCE在单胶束内核中仍旧保持了其内酯结构，HCE-SCMNPs使得难溶于水的有机染料在水溶液中实现pH传感。制备了基于HCE-SCMNPs的卟啉响应的能量转移系统以及三种染料掺杂的单胶束复合白光材料。通过紫外和荧光光谱的研究表明，在含有四苯基卟啉（TPP）的水中，HCE-SCMNPs受到TPP的影响，能够淬灭发射带，实现HCE到TPP的能量转移（HCE作为能量给体，TPP作为能量受体）。这一淬灭过程通过HCE的变化放大了TPP的信号，为卟啉类分子在水体系中的检测提供了可能。HCE的蓝光发射和TPP的红光发射可以由能量转移过程调节至发光颜色平衡。我们在HCE与TPP掺杂的单胶束体系中掺入绿光发射的喹吖啶酮衍生物（8CQA），制备三种染料掺杂的单胶束纳米粒子HCE-TPP-8CQA-SCMNPs。适宜的掺杂比例使得三种染料掺杂的单胶束纳米材料在单一波长激发下获得了白光发射，色坐标为CIE （0.29,0.34）。为水溶性白光材料的制备提供了简便的方法。2.将吩噻嗪类的西弗碱有机染料引入单胶束二氧化硅纳米粒子的内核，获得了水溶性高、选择性好的Fe3+检测传感材料。我们合成了吩噻嗪类西弗碱衍生物（EDDP）并探测了它游离在有机溶剂中和掺杂在单胶束内核（EDDP-SCMNPs）中，两种不同体系对Fe3+和Fe2+的响应过程。实验结果表明，在EDDP的有机溶液中，Fe3+和Fe2+都能够使EDDP的荧光发射淬灭，而在EDDP-SCMNPs的水溶液中，只有Fe3+能够使其荧光淬灭。质谱、核磁氢谱、立体荧光等表征证实了在有机溶剂中的响应过程是由西弗碱碳氮双键断裂导致的，而在水体系中的淬灭过程是由西弗碱结构的EDDP向Fe3+的电子转移导致的。其他过渡金属离子对EDDP-SCMNPs荧光几乎没有影响，说明了EDDP-SCMNPs对Fe3+的检测有很好的选择性，能够区分响应Fe3+和Fe2+。3.将三苯胺类西弗碱衍生物引入表面电荷不同的三种单胶束纳米结构中，制备检测能力增强的水溶性Fe3+荧光检测材料。用共沉淀的方法合成了表面氨基功能化的单胶束纳米粒子（NH2-SCMNPs）作为正电性较强的模板，用双氧水氧化粒子表面巯基获得磺酸基功能化的单胶束纳米粒子（SO3H-SCMNPs）即负电性较强的模板。在这两种改进的单胶束模板中掺杂三苯胺西弗碱衍生物（DBDDP）以制备表面电荷不同的单胶束荧光纳米粒子（DBDDP-SO3H-SCMNP和DBDDP-NH2-SCMNP），用于Fe3+检测。比较了普通单胶束包裹的DBDDP（DBDDP-SCMNPs）、DBDDP-SO3H-SCMNP、DBDDP-NH2-SCMNP和DBDDP的有机溶液对Fe3+响应。其中，DBDDP的有机溶液对Fe3+的荧光发射呈现荧光“turn-on”的响应，而三种单胶束荧光纳米材料的水溶液对Fe3+呈现“turn-off”的响应。用核磁、质谱、荧光光谱等表征了DBDDP在游离溶液中的与三种不同单胶束内核中的Fe3+响应机理。给出了Fe3+的检测能力为：DBDDP-SO3H-SCMNPs>DBDDP-SCMNPs> DBDDP-NH2-SCMNPs。研究表明，DBDDP-SO3H-SCMNPs与DBDDP-SCMNPs对Fe3+的荧光淬灭响应呈线性关系，这为定量测定水体系中的Fe3+提供了方便。本论文通过掺杂和共沉淀的方法将有机荧光染料和官能团引入到单胶束二氧化硅纳米粒子内核或表面从而获得了能量转移、电子转移的复合纳米结构。这一类单胶束二氧化硅荧光纳米粒子具有较小的尺寸、低毒性、发光稳定性和较高的水溶性等优势，有望广泛的应用于生物体系中，成为细胞内响应传感和生物标记的理想材料。更多还原

【Abstract】 Photochemistry has developed rapidly. These days, many researchers inphotochemistry field have shifted research focus from single molecular tomuticomponent nanostructures. Muticomponent nanostructures can be used asfunctional materials, which enable complex process (energy transfer, electron transfer,etc.) to occur in this system. Among most of nanostructures, silica cross-linkedmicellar nanoparticles worked as idea scaffolds for constructing multicomponentfunctional nanomaterials due to its unique features, such as ultrasmall nanosize, highwater solubility, nontoxity and good biocompatibility. Silica cross-linked micellarnanoparticles have been used as scaffolds to encapsulate π-conjugated organic dyesfor water-soluble fluorescence materials design. The main achievements in my Ph.D.thesis are shown as follows.The first part demonstrated that water-soluble fluorescent hybrid materials can besuccessfully synthesized by using silica cross-linked micellar nanoparticles (SCMNPs)as scaffolds to encapsulate fluorescent conjugated dyes for pH sensing, porphyrinsensing and tunable colour emission. Three dyes were separately encapsulated insideSCMNPs (dye-SCMNPs). Each of the dye-SCMNPs indicated longer lifetime inwater than that of free dye dissolved in organic solvent. The7-(hexadecyloxy) coumarin-3-ethylformate (HCE) encapsulated inside SCMNPs (HCE-SCMNPs)exhibited fluorescence quenching by pH change in aqueous media. Furthermore, itwas confirmed that the radiative and non-radiative energy transfer processes bothoccurred between HCE-SCMNPs and tetraphenyl-porphyrin (TPP), which were usedto synthesize the water-soluble TPP sensor. Significantly, HCE-SCMNPs doped with5,12-dicotyl-quinacridone (8CQA) and TPP showed water soluble white lightemission (CIE (0.29,0.34)) upon singlet excitation of376nm due to colouradjustment of8CQA and energy transfer from HCE (donor) to TPP (acceptor).The second part demonstrated that luminescent chemosensor based on silicacross-linked micellar nanoparticles (SCMNPs) was design by encapsulating a schiffbase (4E)-4-((10-dodecyl-10H-phenothiazin-7-yl) methyleneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one (EDDP) for the selective detection of Fe3+. Inthe mixture of acetonitrile and water, the addition of Fe3+/Fe2+to EDDP induced adecrease and a red-shift in fluorescence emission which results from the hydrolysis ofSchiff base. While in aqueous media, EDDP encapsulated inside SCMNPs(EDDP-SCMNPs) shows a high selectively fluorescence quenching by Fe3+. InEDDP-SCMNPs system, the electron transferred from EDDP in the core to Fe3+onthe shell. However, EDDP-SCMNPs showed no sensing ability of Fe2+due to theweak electron-accepting of Fe2+. A strong electron-accepting ability of Fe3+inEDDP-SCMNPs system was verified using UV-absorption, fluorescence emission and3D fluorescence spectra. Significantly, because of the ultrasmall size, nontoxity, highwater solubility and biocompatibility of EDDP-SCMNPs, which can protect theemitting of EDDP in aqueous media, this material exerts promising features inbiological system.In the third part, we first use (4E)-4-(4-(diphenylamino) benzylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one (DBDDP) as a fluorescence turn-on sensor for Fe3+detection in organic solvent. To achieve Fe3+system sensing inaqueous media, DBDDP doped SCMNPs (DBDDP-SCMNPs) and functionalizedSCMNPs (DBDDP-NH2-SCMNPs and DBDDP-SO3H-SCMNPs) are synthesizedusing encapsulation method via electron transfer process. Surface charge ofnanoparticles is used to tune Fe3+fluorescence sensing ability. The sensing abilitiesare following in this order: DBDDP-SO3H-SCMNPs> DBDDP-SCMNPs>DBDDP-NH2-SCMNPs. Electron transfer processes of three nanoparticles areverified by fluorescence emission quenching. The linear correlation betweenquenching intensity and lower concentration of Fe3+was accord to Stern–Volmerequation.Thus, silica cross-linked micellar nanoparticles have been used to encapsulatefluorescent organic dyes for water-soluble sensing. The sensing ability can be adjustedby functionalized SCMNPs. The encapsulating process is easy to build promisingbiocompatibility materials, which can be used in intracellular system.更多还原