Fe_3O_4@SiO_2@CdTe磁性荧光复合微球的制备与表征

采用水热合成法和Stber法制备了氨基功能化SiO2包覆的Fe3O4磁性纳米微球Fe3O4@SiO2-NH2,它与巯基乙酸修饰的CdTe量子点通过酰胺缩合反应,将量子点键合到磁性微球上,制备出单分散性的Fe3O4@SiO2@CdTe磁性荧光双功能微球.用透射电子显微镜、X-射线衍射仪、荧光分光光度计、振动样品磁强计表征了该纳米复合微球的结构和性能.结果表明:Fe3O4@SiO2@CdTe磁性荧光复合微球单分散性好,平均粒径为470nm,饱和磁化强度为37.9emu/g,具有良好的超顺磁性和较高的荧光发光效率.     

Ag@Fe_3O_4@C-CdTe@SiO_2磁性荧光复合微球的制备与光学特征（英文）

先采用一步溶剂热法和水热法制备了碳包覆的Ag@Fe_3O_4核壳型磁性纳米粒子,然后通过表面氨基化改性后与巯基乙酸修饰的CdTe量子点反应,将量子点键合到磁性微球上,最后在其表面包覆上一层二氧化硅壳层,制备出具有荧光增强的Ag@Fe_3O_4@C-CdTe@SiO2磁性荧光复合材料。实验结果表明,该纳米粒子的平均粒径大约为150nm,磁饱和强度为224A/g(22.4emu/g),在室温下具有较好的磁性能。其中Ag@Fe_3O_4@C-CdTe磁性荧光纳米粒子的荧光强度大于Fe_3O_4@C-CdTe,其主要原因是内核为45nm的Ag纳米粒子具有表面等离子体共振作用,能够使其表面或附近的量子点荧光得到增强。     

Fe3O4/CA@CQDs磁性荧光复合材料的制备及表征

为了制备出低毒且性能优异的磁性荧光复合材料,选用发光稳定且生物相容性高的碳量子点(CQDs)作为荧光探针,分别采用一步水热法和化学共沉淀法制备了荧光性能优异的CQDs和超顺磁性四氧化三铁(Fe_3O_4),再以生物相容性较好的柠檬酸(CA)修饰Fe_3O_4,得到表面富含功能性羟基和羧基的Fe_3O_4/CA,通过偶联剂乙二胺将CQDs与Fe_3O_4/CA连接,成功制得Fe_3O_4/CA@CQDs磁性荧光复合材料。并对其进行红外光谱(FTIR)、荧光光谱、振动样品磁强计(VSM)、X射线衍射仪(XRD)、荧光显微镜及透射电子显微镜(TEM)表征,结果表明:Fe_3O_4/CA@CQDs为核壳结构,粒径为30～40 nm,饱和磁化强度为20.14 A·m~2·kg~(-1),该双功能复合材料具有优良的荧光性能和磁性能,细胞毒性低且生物相容性高,有望取代传统荧光磁性纳米复合材料,并广泛应用于生物医学领域。     

磁响应Fe_3O_4@PS胶体光子晶体的制备及性能研究

本文首先通过共沉淀法制备油酸修饰的磁性Fe_3O_4纳米粒子,并将其均匀分散于正辛烷中得到磁流体,然后利用一步细乳液聚合法合成了单分散Fe_3O_4@PS磁性微球。扫描电镜分析结果表明,Fe_3O_4的粒径在13nm左右,所形成的Fe_3O_4@PS微球的粒径在120~150nm左右;VSM测试结果显示所合成的Fe_3O_4@PS微球具有超顺磁性,其饱和磁化强度约为25emu/g;Fe_3O_4@PS微球表面携带明显的负电荷,其表面Zeta电势为-60mV。反射光谱测试结果表明,Fe_3O_4@PS分散于水中形成的胶体溶液在磁场作用下呈现出明亮的结构色,具有明显的带隙特征;随着磁场强度的变化,反射峰波长可在450~650nm进行调谐。     

空心Fe_3O_4纳米微球的制备及超顺磁性

采用水热控制合成法,以六水三氯化铁、柠檬酸三钠和尿素为原料,聚丙烯酰胺为稳定剂, 200?C下反应12 h制备得到了超顺磁性空心Fe_3O_4纳米微球.通过X射线衍射仪、扫描电子显微镜、透射电子显微镜对样品的结构和形貌进行表征,并采用振动样品磁强计测试了样品的磁性能.结果表明:所得样品为具有尖晶石结构的Fe_3O_4纳米微球,尺寸为160 nm左右,呈分等级结构,即整个微球由粒径约18 nm的初级晶粒自组装堆叠而成;室温下表现为典型的超顺磁性,且饱和磁化强度为73.3 emu/g (1 emu/g=1 A·m~2/kg),这种高饱和磁化强度可以由其初级晶粒晶化程度高且粒径较大以及这种特殊的二次自组装结构进行解释.这种Fe_3O_4纳米微球为疏松多孔的空心球状结构,具有粒径分布均匀、分散性良好和超顺磁性的特点,在药物靶向输运和肿瘤热疗中有潜在的应用.     

Ag@Fe3O4@C-CdTe@SiO2磁性荧光复合微球的制备与光学特征

先采用一步溶剂热法和水热法制备了碳包覆的Ag@Fe₃O₄核壳型磁性纳米粒子,然后通过表面氨基化改性后与巯基乙酸修饰的CdTe量子点反应,将量子点键合到磁性微球上,最后在其表面包覆上一层二氧化硅壳层,制备出具有荧光增强的Ag@Fe₃O₄@C-CdTe@SiO₂磁性荧光复合材料。实验结果表明,该纳米粒子的平均粒径大约为150 nm,磁饱和强度为224 A/g（22.4 emu/g）,在室温下具有较好的磁性能。其中Ag@Fe₃O₄@C-CdTe磁性荧光纳米粒子的荧光强度大于Fe₃O₄@C-CdTe,其主要原因是内核为45 nm的Ag纳米粒子具有表面等离子体共振作用,能够使其表面或附近的量子点荧光得到增强。     

高灵敏磁分离荧光传感法检测黄曲酶毒素B1

以自组装方式制备了Au@Fe3O4/核酸适体/氨基-碳量子点磁性生物纳米复合物,并提出一种磁分离荧光传感法用于黄曲霉毒素B1的检测.当样品中有黄曲霉毒素B1时,磁性生物纳米复合物中核酸适体选择性地与黄曲霉毒素B1结合并释放出氨基-碳量子点,经磁性分离后,氨基-碳量子点留在溶液中,体系溶液荧光强度随黄曲霉毒素B1浓度的增大而增强.黄曲霉毒素B1浓度在0.001~1.0ng/mL范围与溶液荧光强度成良好线性关系,线性相关系数为0.996 4,检测限为0.3pg/mL.该方法利用磁性分离技术,有效地消除了背景荧光影响,改善了荧光传感性能.     

钴纳米粒子自组装有序阵列与磁性

采用高温液相分解法制备出平均粒径不同的单分散的钴纳米粒子.用自组装的方法得到二维和三维的钴纳米粒子有序阵列，用透射电子显微镜研究了粒径、温度、有机溶剂以及浓度对钴纳米粒子的自组装的影响.用超导量子干涉仪研究了钴纳米粒子的超顺磁性.这些研究结果为深入研究磁性纳米粒子的物性和在纳米器件中的应用奠定了良好的基础. 关键词： 钴纳米粒子 自组装 超顺磁性     

Synthesis and Adsorption Study of BSA Surface Imprinted Polymer on CdS Quantum Dots

开发了CdS量子点用于牛血清白蛋白(BSA)表面压印的方法,将CdS量子点掺杂进BSA的分子压印聚合物中. 实验过程中对制备条件和吸附条件进行了优化. 量子点(QDs)和量子点分子压印聚合物(QDs-MIP)的形貌用扫描电子显微镜进行了表征. 当该QDs-MIP重新结合模板分子BSA时,CdS量子点的荧光被淬灭. 荧光淬灭的原因可能是量子点与模板蛋白质分子之间的荧光共振能量转移. 该聚合物对压印分子的吸附为单分子层吸附,符合Langmuir等温吸附模型. 化学吸附为速率控制步骤. 该新型聚合物的最大吸附容量可达226.0 mg/g,比未掺杂量子点的BSA压印聚合物提高142.4 mg/g.     

界面电子转移对量子点荧光闪烁行为的影响

利用激光扫描共聚焦显微系统分别测量了CdSe/ZnS量子点在SiO2玻片表面、铟锡氧化物(ITO)纳米粒子表面和聚甲基丙烯酸甲酯(PMMA)薄膜表面上的荧光闪烁行为.研究发现,不同界面环境中量子点的亮态发光持续时间的概率密度都服从指数修正的幂律分布P(t)∝t-αexp(-t/μ).与处于SiO2玻片表面的情况相比,在ITO表面上的单量子点具有非常短暂的亮态发光持续时间,而在PMMA表面的单量子点亮态发光持续时间最长.这种荧光闪烁行为的不同主要归因于量子点与三种材料之间的界面电子转移特性.     

Investigation and Development of Quantum Dot-Encoded Microsphere Bioconjugates for DNA Detection by Flow Cytometry

The development of screening assays continues to be an active area of research in molecular diagnostics. Fluorescent microspheres conjugated to biomarkers (nucleic acids, proteins, lipids, carbohydrates) and analyzed on flow cytometer instruments offered a new approach for multiplexed detection platform in a suspension format. Quantum dots encoded into synthetic microspheres have the potentials to improve current screening bioassays and specifically suspension array technology. In this paper, commercialized quantum dot-encoded microsphere were evaluated and optimized as fluorescent probes to address some of the limitations of suspension array technologies. A comprehensive study was undertaken to adapt the bioconjugation procedure to the quantum dot-encoded microsphere structural and optical properties. Both the leaching-out of quantum dots and microspheres degradation under bioconjugation experimental conditions were minimized. A rapid, efficient and reproducible conjugation method was developed for the detection of single-stranded DNA with the commercialized quantum dot-encoded microsphere. Approximately ten thousand microspheres were conjugated to short amino-modified DNA sequences in one hour with high efficiency. The bioconjugated microspheres acting as fluorescent probes successfully detected a DNA target in suspension with high specificity. Quantum dot-encoded microsphere commercial products are limited which strongly prevents reproducible and comparative studies between laboratories. The method developed here contributes to the understanding of quantum dot-encoded microsphere reactivity, and to the optimization of adapted experimental procedure. This step is essential in the development of this new fluorescent probe technology for multiplex genotyping assay and molecular diagnostic applications.     

微凝胶模板法制备P（AM-co-MAA）/ZnO有机-无机复合微球的研究

采用反相悬浮聚合法合成了甲基丙烯酸（MAA）含量不同的聚丙烯酰胺-甲基丙烯酸[P（AM-co-MAA）]微凝胶,并以其作为模板,通过外源沉积法制备了一系列微米级,表面具有纳米级颗粒堆积的P（AM-co-MAA）/ZnO有机-无机复合微球。复合微球的表面结构与微凝胶的组成和ZnO的沉积量有关。详细考察了MAA含量,Zn（Ac）2浓度,NaOH醇溶液的浓度对ZnO负载量的影响。利用扫描电子显微镜（SEM）,能谱分析仪（EDX）,X衍射分析仪（XRD）,傅里叶红外分析仪（FT-IR）等对复合微球的形貌、组成进行了表征。     

聚苯乙烯荧光乳液的制备及其性能研究

为了实现萘酰亚胺水性化以及提高与纸张的结合性,通过乳液聚合法制备了聚苯乙烯荧光乳液,并对其合成条件进行了优化。通过红外、凝胶渗透色谱法确定其结构;利用紫外、荧光光谱测定其光学性能;采用扫描电镜和透射电镜对其形貌进行了观测。通过计算得出其荧光量子产率为78.57%。聚合物涂布于纸张表面后,初始白度增大了8.19%（ISO）。在紫外老化箱老化48 h后,涂有聚合物的纸张的白度分别比空白纸和涂有小分子荧光增白剂的纸张下降了3.68%（ISO）和3.16%（ISO）,说明所制得的聚合物乳液与纸张结合性好,具有一定的增白及返黄抑制作用。     

One single-step synthesis of multifunctional methylene blue-coated magnetite nanoparticles

This work reports the preparation of hybrid nanoparticles with magnetic and fluorescent properties. The material is based on magnetite nanoparticles (NPs) coated with fluorophore methylene blue (MB). The synthesis of a multifunctional material with magnetic and fluorescent features is carried out in a single step by electrooxidation. The effect of the presence of methylene blue in the synthetic medium is discussed. The presence of MB polymer at the NP surface is demonstrated with visible UV, infrared and Raman spectroscopy. The NPs morphology, structure and size are determined by transmission electron microscopy (TEM) and X-ray diffraction. The magnetic properties are measured with a vibrating sample magnetometer (VMS). In overall, the results show that magnetite NPs generated electrochemically in the presence of MB present a core/shell structure, being the NP at the core surrounded by methylene blue polymer, leading to a nanocomposite or hybrid material.     

Synthesis and Characterization of Magnetic Polymer Microspheres

In this study, amino group–modified magnetic polymer microspheres were synthesized in a well‐shaped spherical form with a size range of 0.6 μm to 0.8 μm by mini‐emulsion polymerization. The morphology, composition, and thermal properties of the magnetic polymer microspheres were characterized by infrared (IR) spectra, transmission electron microscopy (TEM) photographs, particle size analysis, and thermogravimetric analysis (TGA) spectra. The results demonstrate that acrylic acid used for stabilizing the reaction system greatly affects the particle size, magnetite contents, and thermal stability of magnetic polymer microspheres.     

Poly(acrylamide‐co‐acrylic acid)/Poly(vinyl pyrrolidone) Polymer Blends Prepared by Dispersion Polymerization

The structure and properties of a three‐component system, a poly(acrylamide‐co‐acrylic acid)/poly(vinyl pyrrolidone) [P(AM‐co‐AA)/PVP] polymer blend prepared by dispersion polymerization, were studied. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that the resulting P(AM‐co‐AA) microspheres with diameters between 200–300 nm were well‐dispersed in the PVP matrix. Fourier transform infrared spectra (FTIR) showed that intermolecular hydrogen bonding interaction occurred between the dispersed phase and the continuous phase. The mechanical properties of P(AM‐co‐AA)/PVP polymer blends were also determined. With different mass ratios of acrylamide to acrylic acid, it was found that the blends had better mechanical properties with increased AA content.     

FTIR与XRD的均匀粒度分布Ce-Cu/TiO2空心微球制备机理研究

随着社会经济的发展,环境空气品质已经成为研究热点。TiO₂是一种化学稳定性高,耐腐蚀性强,对人体无毒无害的N型半导体材料。利用TiO₂的光催化性能提高室内环境空气品质已经成为研究焦点,但是由于TiO₂只能在紫外光源下才具有较高的光催化效率,而在可见光源下的光催化效率较低,从而极大的限制了TiO₂在室内环境领域的发展。因此,研发在可见光源下具有良好光催化性能的TiO₂复合材料势在必行。利用元素掺杂改性技术与提高比表面积方法可以改善光催化反应过程中量子效率和对光能的利用率,以加快电子和空穴向表面迁移的速率同时降低光生载流子的复合机率。以二氧化硅SiO₂为模板、聚乙烯吡咯烷酮为成膜剂、硝酸铈Ce(NO₃)₃·6H₂O和硝酸铜Cu(NO₃)₂·3H₂O为改性剂采用溶胶-凝胶法制备均匀粒度分布的Ce-Cu/TiO₂空心微球,并将制备过程分为四个阶段,即纳米SiO₂球模板的制备、Ce-Cu/TiO₂-SiO₂复合微球凝胶的制备、Ce-Cu/TiO₂-SiO₂复合微球的制备和Ce-Cu/TiO₂空心微球的制备。利用傅里叶变换红外光谱仪（FTIR）与X射线衍射仪（XRD）对Ce-Cu/TiO₂空心微球的制备过程各阶段生成物进行测试与分析,即在纳米SiO₂球模板的制备阶段从微观角度研究纳米SiO₂球模板的搭建过程,在Ce-Cu/TiO₂-SiO₂复合微球凝胶的制备阶段研究TiO₂附着于纳米SiO₂球模板的过程,在Ce-Cu/TiO₂-SiO₂复合微球的制备阶段研究煅烧工艺对Ce-Cu/TiO₂-SiO₂复合微球中晶相与结构的影响,在Ce-Cu/TiO₂空心微球的制备阶段研究氢氧化钠溶液对Ce-Cu/TiO₂-SiO₂复合微球中纳米SiO₂球模板洗涤效果的影响。利用紫外-可见分光光度计（UV-Vis）对Ce-Cu/TiO₂空心微球的光响应性能进行测试与分析,以研究Ce-Cu/TiO₂空心微球对可见光源的利用效率。利用激光粒度分析仪（LPSA）与扫描电子显微镜（SEM）对Ce-Cu/TiO₂空心微球的粒度分布与微观形貌进行测试与分析,以研究Ce-Cu/TiO₂空心微球的均匀粒度分布效果。结果表明：以Si-O-Si基团构建非晶体结构的无定形态纳米SiO₂球模板,有利于聚乙烯吡咯烷酮在纳米SiO₂球模板表面附着,从而控制Ce-Cu/TiO₂空心微球的空腔结构。Ce-Cu掺杂基本进入TiO₂晶体,极少进入纳米SiO₂球模板晶体,从而抑制了Ce-Cu/TiO₂-SiO₂复合微球中TiO₂由锐钛矿相向金红石相的转变。Ce-Cu掺杂TiO₂可以促使TiO₂内部形成新的能级,实现能量较小的光子捕获e-和h+,从而提高Ce-Cu/TiO₂空心微球对可见光源的利用效率。Ce-Cu/TiO₂空心微球的表面光滑且不存在明显的缺陷,其形貌呈现良好的球体且粒径分布均匀,即d₉₀为219.54 nm,d₅₀为151.60 nm、d₁₀为103.84 nm,以及d₉₀-d₁₀为115.70 nm。研究结果为进一步获得可见光源下具有良好光催化性能的均匀粒度分布Ce-Cu/TiO₂空心微球提供理论依据和研究基础。     

CdSe/CdS核壳量子点复合材料合成及其在白光发光二极管中的应用

采用有机化学合成法,利用正三辛基膦(TOP)辅助的快速注入生长方法,改进传统的制备工艺,实现了CdSe/CdS厚壳层核壳(8.6 ML)量子点复合材料的合成制备,并对所合成的核、核壳量子点及其复合材料的晶格结构、形貌特点与发光性质进行了XRD、TEM、SEM、UV-Vis、PL表征和红光补偿效果测试。测试结果表明,CdSe核具有立方纤锌矿晶格结构;CdSe/CdS量子点复合材料直径为45~75μm,呈菱形规则形貌,且颗粒分散性良好。采用该方法,可以提高量子产率,产率由4%(CdSe核)升至48%(CdSe/CdS核壳量子点);可以增强激子态发光能力,CdSe/CdS核壳量子点复合材料的荧光强度约为CdSe核的13倍。将该材料与YAG∶Ce~(3+)黄色荧光粉组合应用,获得了高光效(148.29 lm/W)、高显色指数(Ra为90.1,R9为97.0)的白光发光二级管,表明按照上述方法获得的CdSe/CdS核壳量子点复合材料在白光发光二极管中深红光波段具有较好的补偿效果。     

Preparation of magnetic polylactic acid microspheres and investigation of its releasing property for loading curcumin

In order to obtain a targeting drug carrier system, magnetic polylactic acid (PLA) microspheres loading curcumin were synthesized by the classical oil-in-water emulsion solvent-evaporation method. In the Fourier transform infrared spectra of microspheres, the present functional groups of PLA were all kept invariably. The morphology and size distribution of magnetic microspheres were observed with scanning electron microscopy and dynamic light scattering, respectively. The results showed that the microspheres were regularly spherical and the surface was smooth with a diameter of 0.55-0.75 μm. Magnetic Fe₃O₄ was loaded in PLA microspheres and the content of magnetic particles was 12 wt% through thermogravimetric analysis. The magnetic property of prepared microspheres was measured by vibrating sample magnetometer. The results showed that the magnetic microspheres exhibited typical superparamagnetic behavior and the saturated magnetization was 14.38 emu/g. Through analysis of differential scanning calorimetry, the curcumin was in an amorphous state in the magnetic microspheres. The drug loading, encapsulation efficiency and releasing properties of curcumin in vitro were also investigated by ultraviolet-visible spectrum analysis. The results showed that the drug loading and encapsulation efficiency were 8.0% and 24.2%, respectively. And curcumin was obviously slowly released because the cumulative release percentage of magnetic microspheres in the phosphate buffer (pH=7.4) solution was only 49.01% in 72 h, and the basic release of curcumin finished in 120 h.     

电介质球复合纳米天线对荧光定向发射的增强

在纳米光子学中,提高荧光物质的定向发光强度是许多应用要解决的关键问题。为了优化电介质纳米天线的荧光增强能力,本文提出了一种由硅纳米球二聚体与TiO 2微球组成的电介质球复合纳米天线。通过时域有限差分法,本文分别从量子产率增强、荧光收集效率增强以及荧光激发率增强3个方面研究了该复合纳米天线对荧光的增强效果。结果表明,这种复合纳米天线不仅可以解决单个TiO 2微球增强荧光时量子产率较低的问题,还可以弥补单个硅纳米球二聚体增强荧光时荧光收集效率较差的不足。该复合纳米天线可使CdSe量子点的量子产率增强约4倍、荧光收集效率增强约2倍。此外,由于硅纳米球二聚体与TiO 2微球对荧光激发过程具有增强效果,该复合天线最终可以产生较高的荧光定向增强倍数。在量子点发光的中心波长523 nm处,荧光定向增强约为3064倍。