非对称Fe_3O_4-SiO_2介孔纳米粒子的合成与性质

采用高温水解法合成了具有超顺磁性且表面修饰的Fe3O4纳米粒子,将该Fe3O4纳米粒子作为种子,采用"非经典控核生长"方法在其表面生长SiO2棒状结构,获得了非对称Fe3O4-SiO2介孔纳米粒子,通过调节硅源加入量调控非对称粒子棒状部分的长度.由于一次生长出的结构尺寸有限,使用"二次生长法"进一步增加纳米棒部分的长度,最后对该非对称粒子进行了药物的装载与释放实验,表明其对阿霉素具有缓释作用.     

氧化铁磁性纳米粒子的表面配体交换及相转移

以苯甲醇为单一溶剂, 通过常压、高温热解乙酰丙酮铁, 制备了尺寸单分散的四氧化三铁磁性纳米粒子. 采用透射电镜(TEM), X射线衍射(XRD), 动态光散射(DLS)等方法对粒子形貌和结构进行了表征. 利用傅里叶变换红外(FT-IR)光谱和热重分析(TGA)研究了所制备纳米粒子的表面化学, 结果表明稳定四氧化三铁粒子的是苯甲酸分子, 且表面覆盖度小于20%. 所制备的磁性纳米粒子可以在室温下方便地进行表面配体交换, 从而为氧化铁磁性纳米粒子的功能化提供新的途径.     

信号肽功能化二氧化硅纳米颗粒的线粒体靶向作用研究

以N-(p-Maleimidophenyl)isocyanate(PMPI)为交联剂, 将线粒体信号肽分子共价修饰到二氧化硅荧光纳米颗粒表面, 构建线粒体信号肽功能化二氧化硅荧光纳米颗粒. 采用荧光分光光度计、Zeta电位仪以及透射电子显微镜对修饰前后的二氧化硅纳米颗粒进行了表征. 结果表明, 信号肽可被成功修饰在纳米颗粒表面, 并且纳米颗粒粒径在信号肽分子修饰前后没有发生明显变化. 以分离纯化的细胞核作为对照, 采用流式细胞术考察了信号肽功能化二氧化硅荧光纳米颗粒与分离纯化后的线粒体的相互作用. 结果表明, 线粒体信号肽修饰到二氧化硅纳米颗粒表面后依然保持良好的生物活性, 能够介导二氧化硅纳米颗粒特异性识别及结合分离纯化的线粒体, 从而为线粒体监测及其功能调控研究提供了新的思路.     

热处理温度对BaFe12O19粉体微结构和磁性的影响

永磁铁氧体;热处理温度对BaFe12O19粉体微结构和磁性的影响     

Synthesis of Amphiphilic Silica Nanoparticles for Latent Fingerprint Detection

4-(Chloromethyl) phenyltrichlorosilane was used to modify silica spheres to obtain a sensitive and selective nanoparticle powder for detecting latent fingerprints. Various analytical techniques were used to characterize the nanoparticles and to show that the structure and properties are well-suited for forensic science. The synthesis of the particles was optimized based on the performance in terms of detection and the development of a test set of latent prints. The new material offers simple synthesis, convenient use for routine casework, and low price. These advantages suggest potential application for crime scene investigations.     

Synthesis of Nanoscale Shell-core Titania Coated Silica Particles in the Presence of Polyether Polyamine and the Phase Transition

IntroductionTitanium dioxide with the rutile or the anatasestructure as,in principle,a white pigmentis widelyused as paints and plastic additives because of itshigh refractive index,oil adsorption,chemical orthermal stability[1— 4 ] .The most common manu- fac-ture of this material is based on the digestion of theore ilmenite(Fe O· Ti O) with sulfuric acid,fol-lowed by hydrolyzing the solution of titanium ionsand the calcination of the hydrous titanium ox-ides[5] .Another industrial prepara…     

磁性石墨烯@聚多巴胺纳米复合材料分离去除水中双酚A

本文通过水热法和多巴胺的自我团聚反应合成了磁性石墨烯@聚多巴胺(PDA@MG)纳米复合材料,该材料具有表面积大,含有丰富的π电子共轭体系、很好的水溶液分散性,易分离及可重复使用等特点。以PDA@MG为吸附剂材料,研究了其对水溶液中双酚A(BPA)的吸附性能。考察了吸附时间、温度、溶液的pH、吸附剂的用量等因素对该材料吸附性能的影响。结果表明在优化实验条件下,PDA@MG对BPA的最大吸附容量为151.3mg/g。PDA@MG具有优异的循环吸附性能,经过10次循环使用后其吸附能力没有明显减弱。     

The Effect of Gelatin on the Preparation of Silica Coated Iron Particles

A method is described for coating fine iron particles(～1μm) with a uniform silica layer,produced by the hydrolysis of tetraethyl orthosilicate.The presence of a small amount of gelatin on the surface of the iron particles facilitates this process.The X-ray photoelectron measurements indicated that the gelatin interacted with the surface of the iron particles by means of both nitrogen(in -NH2 groups) and oxygen(in -COOH groups) and then bound to the silica.The silica coating increases the resistance of the iron particles to oxidation on heating in air,which makes the temperature at which an observable oxidization occurs from 330 ℃ to 400 ℃ raised.     

功能化磁性纳米粒子在乳状液制备及破乳中的应用及作用机制

功能化磁性纳米粒子因其独特的理化性质,在乳状液制备与破乳领域的应用受到广泛关注。本文归纳了功能化磁性纳米粒子的制备方法、合成结构与特征性质,阐述了其在乳状液制备及破乳中的应用过程,重点分析了磁性纳米粒子在溶液中良好分散、稳定吸附于油水界面排布为膜结构的作用行为,尤其是磁性纳米粒子的磁响应特征对乳状液中界面性质、液滴形貌及运动状态的影响,并进一步总结出其表面性质及作用行为对稳定乳状液或使乳状液破乳的规律。针对磁性纳米粒子对乳状液稳定性影响规律的探究可为其在应用领域提供理论支持。最后本文就功能化磁性纳米粒子研究中亟待解决的新问题作出展望。     

Recent Advances of Cell Membrane Coated Nanoparticles in Treating Cardiovascular Disorders

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, causing approximately 17.9 million deaths annually, an estimated 31% of all deaths, according to the WHO. CVDs are essentially rooted in atherosclerosis and are clinically classified into coronary heart disease, stroke and peripheral vascular disorders. Current clinical interventions include early diagnosis, the insertion of stents, and long-term preventive therapy. However, clinical diagnostic and therapeutic tools are subject to a number of limitations including, but not limited to, potential toxicity induced by contrast agents and unexpected bleeding caused by anti-platelet drugs. Nanomedicine has achieved great advancements in biomedical area. Among them, cell membrane coated nanoparticles, denoted as CMCNPs, have acquired enormous expectations due to their biomimetic properties. Such membrane coating technology not only helps avoid immune clearance, but also endows nanoparticles with diverse cellular and functional mimicry. In this review, we will describe the superiorities of CMCNPs in treating cardiovascular diseases and their potentials in optimizing current clinical managements.     

Detection of Intracellular Proteins and Biomarkers Using Modified Silica Nanoparticles and Flow Cytometry In vitro

In this paper, antibody-modified silica nanoparticles were successfully synthesized, and their average diameter was (109±9) nm. These particles were mixed with cell extracts to target a protein, then, an antibody labeled with fluorescein isothiocyanate(FITC) was added to form FITC-labeled nanoparticle complexes and the product was analyzed using flow cytometry. The results confirm that the intracellular proteins and biomarkers were precisely and sensitivity detected by the novel method in vitro. The FITC intensity of Akt antibody-conjugated particles was increased ≥ 10-fold compared with that of control samples in MCF-7 cells. Furthermore, it can also simultaneously measure several proteins when modified with different antibodies.     

Free Radical Scavenging Magnetic Iron-Based Nanoparticles in Hyperbranched and Linear Polymer Matrices

Magnetic iron nanoparticles are attracting a great deal of research and application interest in diversified fields. In this present investigation, iron nanoparticles were prepared by a in-situ chemical reduction technique in a combination of polyaniline (PANI)-polyacrylamide (PA) and PANI-hyperbranched polyurethane (HBPU) matrices to judge the suitability of hyperbranched system. The formation of the nanoparticles in polymer matrices has been investigated by FTIR, UV, XRD, SEM and TEM studies. Narrower size with better dispersion and more stable nanoparticles were found in a hyperbranched matrix system compared to a linear one. The particle size was found to be in the range of 10–20 nm and 12–35 nm in HBPU-PANI and PA-PANI matrices, respectively. Both the nanocomposites exhibit synergistic free radical scavenging capability towards 2,2-diphenyl-1-picrylhydrazyl (DPPH). The magnetic hysteresis loop of the nanocomposites indicates the super-paramagnetic behavior. The hyperbranched system is more thermostable than the linear system by 70°C.     

羧甲基壳聚糖磁性纳米粒子的合成及应用

通过合成油酸修饰的Fe3O4纳米粒子和羧甲基壳聚糖直接包埋油酸修饰的Fe3O4纳米粒子的两步合成法制备了羧甲基壳聚糖磁性纳米粒子。采用透射电子显微镜、傅里叶变换红外光谱、振动样品磁强计和同步热分析测试技术对制备的羧甲基壳聚糖磁性纳米粒子进行了表征。所得磁性纳米粒子呈规则球形,粒径约为10 nm;表面含羧基,且具有很好的顺磁性和稳定性。考察了羧甲基壳聚糖磁性纳米粒子对阿霉素的载药量和对阿霉素在磷酸盐缓冲溶液中的缓释性能。结果表明,磁性纳米粒子对阿霉素展示了较高的载药量(91.8 mg/g),结合了阿霉素的磁性复合物对阿霉素的缓释作用明显,说明制备的羧甲基壳聚糖磁性纳米粒子有望作为治疗肿瘤的纳米磁靶向药物输送载体。     

Synthesis of Phenylboronic Acid-Functionalized Magnetic Nanoparticles for Sensitive Soil Enzyme Assays

Soil enzymes, such as invertase, urease, acidic phosphatase and catalase, play critical roles in soil biochemical reactions and are involved in soil fertility. However, it remains a great challenge to efficiently concentrate soil enzymes and sensitively assess enzyme activity. In this study, we synthesized phenylboronic acid-functionalized magnetic nanoparticles to rapidly capture soil enzymes for sensitive soil enzyme assays. The iron oxide magnetic nanoparticles (MNPs) were firstly prepared by the co-precipitation method and then functionalized by (3-aminopropyl)triethoxysilane, polyethyleneimine and phenylboric acid in turn, obtaining the final nanoparticles (MNPPBA). Protein-capturing assays showed that the functionalized MNPs had a much higher protein-capturing capacity than the naked MNPs (56% versus 6%). Moreover, MNPPBA almost thoroughly captured the tested enzymes, i.e., urease, invertase, and alkaline phosphatase, from enzyme solutions. Based on MNPPBA, a soil enzyme assay method was developed by integration of enzyme capture, magnetic separation and trace enzyme analysis. The method was successfully applied in determining trace enzyme activity in rhizosphere soil. This study provides a strategy to sensitively determine soil enzyme activity for mechanistic investigation of soil fertility and plant–microbiome interaction.     

Electrochemical Behavior of Herbal Antitumor Drug Aloe‐Emodin at Carbon‐Coated Nickel Magnetic Nanoparticles Modified Glassy Carbon Electrode

The electrochemical behavior of aloe‐emodin (AE), an important herbal antitumor drug, was investigated at a carbon‐coated nickel magnetic nanoparticles modified glassy carbon electrode (CNN/GCE). A couple of well‐defined redox peaks was obtained. Some electrochemical parameters of AE at a CNN/GCE, such as the charge number, exchange current density, standard heterogeneous rate constant, were measured. The square wave voltammetry (SWV) response of AE was linear with the concentration over two concentration intervals viz. 6.24×10^?9?1.13×10^?6 M and 1.13×10^?6?1.23×10^?5 M, with a detection limit of 2.08 nM. A fast, simple and sensitive detection and analysis of AE was developed.     

乙二胺改性磁性壳聚糖纳米粒子对酸性染料的吸附特性

利用乙二胺改性磁性壳聚糖纳米粒子(EMCN)吸附酸性橙7 (AO7)和酸性橙10 (AO10). EMCN制备时先通过在由环已烷/正已醇、壳聚糖和铁盐组成的反相微乳体系中加NaOH溶液沉淀剂, 得到磁性壳聚糖纳米粒子, 再经乙二胺改性以增加氨基含量和提高吸附容量. 透射电镜表明, EMCN分散良好, 粒径15-40 nm. 吸附实验表明, AO7和AO10最佳吸附分别在pH 4.0和pH 3.0. EMCN具有粒径小和高表面活性, 因此吸附速率快. 吸附平衡符合Langmuir模型, AO7和AO10的最大吸附容量分别为3.47和2.25 mmol·g^-1. 热力学分析表明吸附过程放热, 且能自发进行. EMCN可用NH⁴OH/NH⁴Cl (pH 10.0)溶液再生并可重复使用.     

共同装载吴茱萸碱和Fe3O4纳米粒子的磁性药物载体的制备

以单甲醚-聚乙二醇-聚（丙交酯-乙交酯）（mPEG-PLGA）作为载体,采用溶液透析的方法共同装载抗癌药物吴茱萸碱和Fe₃O₄ 磁性纳米粒子. 通过透射电子显微镜、红外光谱、紫外-可见光谱及体外释放实验、普鲁士蓝染色、体外毒性实验和磁靶向研究,综合评价了磁性纳米药物载体的性能. 结果表明,磁性药物载体胶束分散性良好,粒径均一,有较高的载药量和包封率,能够实现药物缓释,具有磁靶向特性.     

溶剂热处理对超顺磁性球形γ－Al2O3催化剂载体性能的影响

 在前期制备超顺磁性氧化铝催化剂载体的基础上，对采用油中成型（内凝胶）方法制备的磁性球形氢氧化铝的晶型、比表面积、孔体积、孔分布和磁性能等性质进行了研究．实验中发现，溶剂热处理过程不仅有利于油中成型的无定形氢氧化铝微球向拟薄水铝石转化，而且可以增大载体的比表面积和孔体积．通过控制溶剂热处理的温度和时间，可有效地调控载体的孔分布．实验中制备的磁性氧化铝载体的物理化学性能，达到了硝基苯和正己烯催化加氢反应所需的要求．     

线性麦芽糊精聚合物功能化Fe3O4纳米复合物药物载体的合成和应用

采用共沉淀法制备得到了线性麦芽糊精聚合物功能化的Fe₃O₄磁性纳米粒子(LM-SP-MNPs),通过傅里叶变换红外光谱、透射电子显微镜、热重分析等技术对其结构、形貌进行了表征。 其粒径大小为(12±2) nm。 选取抗癌药物盐酸阿霉素(DOX)作为模型药物,运用荧光光谱法研究了LM-SP-MNPs的载药性能和释放行为,探讨了pH值对LM-SP-MNPs药物释放性能的影响。 最适pH条件下,LM-SP-MNPs对盐酸阿霉素的最大吸附量约为357.1 mg/g,吸附等温线符合Freundlich等温吸附模型。 LM-SP-MNPs与盐酸阿霉素的复合物(DOX@LM-SP-MNPs),在37 ℃的条件下药物在酸性条件下的释放效率大于中性条件。 pH=5.3时,盐酸阿霉素在7 h内的累积释放率为26.9%。 此外,细胞毒性试验表明,LM-SP-MNPs具有良好的生物相容性,而DOX@LM-SP-MNPs和肝癌细胞共培养后可以明显杀死HepG2肝癌细胞。     

Structural and Magnetic Properties of Chemically Synthesized Pd-Modified NiFe2O4 Nanoparticles

Magnetic nanoparticles of NiFe₂O₄-Pd composites have been synthesized using a simple, low cost, sol-gel auto-combustion method. As-prepared samples were sintered at 800 ℃ for 6 h in order to develop the crystalline phase. X-ray diffraction confirmed the spinel structure of the ferrite samples. Structural morphology and size of the nanoparticles were evaluated using a field emission scanning electron microscope. Magnetic hysteresis loops were obtained at 300 and 100 K using a physical properties measurement system. The value of saturation magnetization was observed to decrease at the temperatures with the increase of Pd contents up to 5% but then a sudden rise in saturation magnetization was observed for the addition of 10% Pd in NiFe₂O₄.