ATP适体接枝Fe3O4纳米粒子的制备及化学发光酶检测应用

制备了油酸修饰的Fe₃O₄纳米粒子,利用盐酸多巴胺对其表面进行氨基化改性,制得水分散性良好的Fe₃O₄纳米粒子,用X射线衍射、透射电镜、傅里叶变换红外光谱仪、振动样品磁强计和紫外-可见吸收光谱进行表征。随后,将氨基修饰的三磷酸腺苷（ATP）适体接枝到Fe₃O₄纳米粒子上,结合荧光素酶化学发光法进行ATP的定量检测,并应用于市售酸奶中乳酸菌ATP含量的检测,其灵敏度高、重现性好。各项实验结果表明所制备的Fe₃O₄纳米粒子是一种分散性好、易分离的载体,其粒径均一、稳定、磁性强、与适体结合性能好,拓展了Fe₃O₄纳米粒子在分析检测领域的应用。     

空心结构磁性固体碱催化剂Fe3O4@LDO的制备与性能

基于水滑石类化合物的复合氧化物(LDO)是一类性能优异的固体碱催化剂,对其进行改性和功能化引起了越来越多的关注。本文将空心结构和Fe_3O_4引入到镁铝复合氧化物中,制备了一种空心结构磁性固体碱催化剂Fe_3O_4@LDO。这种空心结构磁性固体碱催化剂粒子具有以镁铝复合氧化物为壳层,空心Fe_3O_4为核的核壳结构。由于其独特的空心结构,Fe_3O_4@LDO粒子的悬浊液具有良好的稳定性,将其应用于催化Knoevenagel缩合反应,达到平衡后苯甲醛的转化率约为62%,显示出较好的催化性能。同时,Fe_3O_4@LDO粒子具有较强的磁性,非常方便分离与回收,是一种性能优良的磁性固体碱催化剂。     

Fe3O4@SiO2@mTiO2介孔多功能纳米复合颗粒的制备及载药能力

以溶剂热法制备氨基功能化的Fe_3O_4纳米颗粒为磁核,结合溶胶-凝胶法和模板法在其表面先后包覆上致密的SiO_2层和介孔TiO_2层,制备了磁性-发光-微波热转换性-介孔结构为一体的多功能核-壳结构纳米复合颗粒,并对其结构、性能及载药能力进行了研究。XRD分析表明:Fe_3O_4表面包覆上了无定形结构的SiO_2和TiO_2。TEM照片表明:所得的纳米复合颗粒具有明显的核壳结构和完美的球形,构成核的Fe_3O_4颗粒的尺寸在40~50 nm之间,Fe_3O_4@SiO_2@mTiO_2核壳结构纳米复合颗粒的尺寸为60~70 nm,壳层厚度约10 nm,并可观察到壳层中清晰的孔状结构。磁性、荧光光谱和微波热转换特性分析表明:该复合颗粒同时具有良好的发光性、磁性和微波热转换特性。N_2气吸附及药物负载率分析表明,该复合颗粒具有较高的比表面积(640 m~2·g~(-1))和介孔结构(孔径约2.8 nm)并且具有较高的药物负载率。     

钛铁矿制备二氧化钛-四氧化三铁复合材料及其光催化应用

TiO_2因具有多种优异的特性被广泛应用在半导体光催化领域,但是纳米结构的TiO_2颗粒细微,在进行光催化反应之后,难以回收再利用。本文以廉价钛铁矿为原料制备光催化剂TiO_2,同时利用副产物铁合成Fe_3O_4,并采用简单温和的浸渍法制备Fe_3O_4/TiO_2磁性复合材料。通过XRD、FT-IR、SEM、EDS等手段对材料形态结构进行表征分析,并以光降解有机污染物若丹明B为探针反应,考察其光催化性能。结果表明,质量比为1∶10的Fe_3O_4/TiO_2复合材料结构稳定、分散均匀,具有最优的光催化活性(波长356nm下反应3h,若丹明B降解率达到64.0%),并表现出良好的重复性。同时,动力学结果显示降解符合一级反应动力学。     

叶酸对磁性Fe_3O_4纳米粒子的表面修饰

以FeCl3·6H2O作为单一铁源,1,6-己二胺作为胺化试剂,利用无模板的溶剂热方法制备了胺基功能化的磁性Fe3O4纳米粒子,并利用其键合叶酸分子,制备出表面修饰了叶酸的磁性Fe3O4复合纳米粒子。利用傅里叶变换红外光谱仪、X-射线衍射仪、透射电镜、差热-热重分析仪和振动样品磁强计对所得纳米粒子的形貌、粒径、化学组成和磁性能进行了表征。结果表明,叶酸分子通过化学键牢固键合在磁性纳米Fe3O4粒子表面,叶酸修饰的复合纳米粒子仍然具有良好的磁性能。     

硫酸化糖修饰Fe_3O_4@SiO_2纳米粒子诱导肿瘤细胞凋亡研究

首先制备了具有磁性的Fe_3O_4@SiO_2纳米粒子,然后通过"Click"化学反应在粒子表面修饰选择性保护的N-乙酰氨基葡萄糖,再对糖硫酸化,得到一系列具有核/壳结构、表面具有不同硫酸基图案的糖功能化的Fe_3O_4@SiO_2纳米粒子.采用X射线衍射(XRD)、X射线光电子能谱(XPS)和透射电子显微镜(TEM)等对Fe_3O_4@SiO_2纳米粒子修饰前后的成分和形貌进行了分析,并从细胞水平初步研究了硫酸化糖修饰的Fe_3O_4@SiO_2纳米粒子诱导肿瘤细胞凋亡及对蛋白质信号的影响.结果表明,所制备的Fe_3O_4@SiO_2纳米粒子尺寸均一,分散性良好,经硫酸化糖修饰后,平均粒径由110～130 nm增加至160～180 nm.经硫酸化糖修饰后的纳米粒子能够有效进入肿瘤细胞,调节Bcl-2/Bax通路的蛋白表达水平,进而诱导细胞凋亡并呈现浓度依赖关系,但不会影响正常细胞.这一活性的差异与纳米粒子表面糖的硫酸基图案有关.     

泡沫镍负载Fe2O3@Ni3S2纳米线网状结构电极的制备及其电催化析氧性能

通过两步水热法制备泡沫镍(NF)负载Fe_2O_3纳米粒子@Ni_3S_2纳米线网状结构电极(Fe_2O_3@Ni_3S_2/NF)。运用X射线衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、N_2吸附-脱附测试等方法对电极材料的物相和微观结构特征等进行了表征。水热条件下原位表面化学刻蚀生成的Ni_3S_2纳米线与三维多孔NF基体间拥有强结合力和低界面电阻,Fe_2O_3粒子均匀分布在纳米线的表面。在1 mol·L~(-1)的KOH溶液中,运用线性扫描伏安测试(LSV)、计时电位法、电化学交流阻抗测试(EIS)等对电极的电催化析氧(OER)性能进行了测试。结果表明:在100 mA·cm~(-2)的超高电流密度下,Fe_2O_3@Ni_3S_2/NF电极的OER过电势仅为223 mV,比Ni_3S_2/NF材料的过电势降低了285 mV;经过10 h计时电位测试,性能保持率高达80%。     

配体交换法制备水中高分散稳定性的多羧基修饰Fe3O4纳米颗粒

采用油相高温分解法制备了粒径可控且单分散的油溶性Fe3O4磁性纳米粒子(MNPs-OA), 并通过配体交换对其表面进行了亲水性修饰, 制备了柠檬酸(CA)、 N-(三甲氧基硅丙基)乙二胺三乙酸钠(SiCOOH)、 丁烷四羧酸(BTCA)和乙二胺四乙酸 (EDTA)四钠4种多羧基配体修饰的水溶性Fe3O4磁性纳米粒子(MNPs-CA, MNPs-SiCOOH, MNPs-BTCA 和MNPs-EDTA), 其中首次选用四羧基配体BTCA和EDTA四钠来修饰Fe3O4磁性纳米粒子(MNPs). 对油溶性MNPs和4种水溶性MNPs的形貌、 结构、 化学组成和磁性能进行了表征, 并对4种多羧基配体修饰的水溶性MNPs在水相中的稳定性和分散性进行了表征. 结果表明, 所得MNPs的平均粒径为15 nm, 具有超顺磁性, 配体交换后的水溶性MNPs具有良好的亲水性, 并在弱酸～碱性很宽的pH范围内具备良好的分散稳定性. 此类多羧基修饰的水溶性MNPs可与适当的阳离子聚电解质进行组装, 从而得到在磁靶向载体和磁共振造影(MRI)显影中具有良好应用前景的磁性自组装微囊.     

一锅法制备Co3O4/g-C3N4复合光催化剂及其光催化性能

以三聚氰胺和六水合氯化钴为原料,一锅法制备Co_3O_4负载的多孔石墨相氮化碳(Co_3O_4/g-C_3N_4)复合光催化材料。采用X射线衍射(XRD)、傅里叶变换红外(FT-IR)光谱、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外-可见漫反射光谱(UV-Vis DRS)、光致发光光谱(PL)等手段对其结构和光学特性进行表征。以盐酸四环素(TC)为目标污染物,评价了不同负载量Co_3O_4/g-C_3N_4复合光催化剂的可见光催化性能。结果表明,所制备的Co_3O_4/g-C_3N_4复合光催化剂为多孔结构,其比表面积较大,并在可见光区域具有显著的吸收。利用原位生成的Co_3O_4纳米粒子在氮化碳表面形成异质结构,可有效转移光生载流子,降低光生电子-空穴的再结合率,从而提高光催化活性。并且存在最佳Co_3O_4复合量,当六水合氯化钴加入量为三聚氰胺的8%(w/w)时,所制备的复合光催化剂CoCN-8具有最佳的光催化性能。在可见光的照射下,60 min内可降解85%的TC,而同样条件下,纯g-C_3N_4仅降解23%的TC。     

Au掺杂Fe3O4纳米粒子酶传感器的制备及其应用于有机磷农药检测的研究

合成了金掺杂的四氧化三铁纳米粒子(Au-Fe₃O₄), 以壳聚糖为交联剂, 制备了电流型乙酰胆碱酯酶(AChE)生物传感器, 并将其应用于有机磷农药(OPs)的检测. 实验表明, Au-Fe₃O₄纳米粒子具有良好的生物兼容性, 能够有效地促进电子传递, 修饰了Au-Fe₃O₄纳米粒子的酶传感器, 响应速度快, 检测灵敏度高, 稳定性好; 固定在传感器上的乙酰胆碱酯酶有良好的酶动力学响应, 其表观米氏常数( )为10.3 mmol/L. 利用有机磷农药对乙酰胆碱酯酶的抑制作用, 以硫代乙酰胆碱(ATCh)为底物, 对有机磷农药敌敌畏进行了检测, 检测限达到4.0×10^－13 mol/L.     

磁靶向纳米Fe3O4-TiO2复合物的制备及其对肝癌细胞的光催化杀伤效应

采用三种低温溶胶-凝胶法制备了具有不同Fe₃O₄掺杂量的磁靶向纳米Fe₃O₄-TiO₂复合物, 通过X射线衍射(XRD)、透射电镜(TEM)、傅里叶变换红外(FTIR)光谱、紫外-可见(UV-Vis)光谱、荧光光谱(FS)及磁性能分析等表征方法筛选出包覆均匀、分散性好、磁性能优异及光催化活性较高的纳米Fe₃O₄-TiO₂复合物. 以四甲基偶氮唑蓝(MTT)法检测肝癌细胞(HepG2)的存活率, 考察纳米Fe₃O₄-TiO₂复合物在外磁场作用下对HepG2 细胞的光催化杀伤效应. 结果表明: 采用方法三制备的5%(质量分数)Fe₃O₄-TiO₂复合物具备核-壳结构, 在混悬液中分散性较好, 平均粒径约为50 nm, 具有较强的光催化活性和良好的磁响应性, 同时将纳米TiO₂的光响应范围拓宽至444 nm; 在外磁场作用下, 紫外光和可见光激发纳米Fe₃O₄-TiO₂复合物对HepG2细胞的杀伤效应差异不大, 且均强于纳米TiO₂; 其杀伤效应在0-1.0 T范围内随着外磁场强度的增大而增强.     

Ultrasonic synthesis of polyaniline nanotubes containing Fe3O4 nanoparticles

Polyaniline (PANI) nanotubes containing Fe₃O₄ nanoparticles were synthesized under ultrasonic irradiation of the aqueous solutions of aniline, ammonium peroxydisulfate (APS), phosphoric acid (H₃PO₄), and the quantitative amount of Fe₃O₄. It was found that the obtained samples had the morphologies of nanotubes. TEM images and selected area electronic diffractions showed that Fe₃O₄ nanoparticles were embedded in PANI nanotubes. We thought that the mechanism of the formation of PANI/Fe₃O₄ nanotubes could be attributed to the ultrasonic irradiation and the H₃PO₄-aniline salt template. The molecular structure of PANI/Fe₃O₄ nanotubes were characterized by Fourier transform infrared spectroscopy (FTIR), UV-vis absorption spectra and X-ray diffraction (XRD). The conductivity and magnetic properties of the PANI nanotubes containing Fe₃O₄ nanoparticles were also investigated.     

Hydrothermal synthesis of monodisperse Fe3O4 nanoparticles based on modulation of tartaric acid

In this paper, monodisperse Fe₃O₄ nanoparticles with single crystalline structure were synthesized via a facile environment-friendly method. And the size of the nanoparticles ranges from 10 nm to 15 nm. As-synthesized Fe₃O₄ were characterized by X-ray diffraction instrument (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectrometer and field emission transmission electron microscope (FE-TEM). The effect of tartaric acid (TA) amount on products was investigated by XRD and TEM. The results indicated that TA could commendably modulate the crystalline phase, morphology and size of nanometer Fe₃O_4. A possible generated mechanism of Fe₃O₄ crystals was proposed in virtue of UV–vis absorption spectra. Besides, the magnetic properties of as-synthesized Fe₃O₄ were detected.     

Enhancing of asphaltene adsorption onto Fe3O4 nanoparticles coated with metal-organic framework Mil-101 (Cr) for the inhibition of asphaltene precipitation

In this study, the potential of MOF (Mil-101-Cr)-coated Fe₃O₄ magnetic nanoparticles (Fe₃O₄-MOF MNPs) for asphaltene adsorption was investigated for the first time and the results were compared with magnetic Fe₃O₄ nanoparticles (Fe₃O₄ MNPs). The coprecipitation method was used for the synthesis of both nanoparticles and were verified using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM). The initial asphaltene concentration, nanoparticles concentration, and temperature were the investigated parameters that influenced the adsorption capacity. Increasing the asphaltene concentration, decreasing the mass of nanoparticles, and reducing the temperature could enhance the maximum asphaltene adsorption capacities of 0.79 for Fe₃O₄ MNPs and 0.98?mg?m^?2 for Fe₃O₄-MOF MNPs. Adsorption isotherms tests showed that the Langmuir model was in agreement with the experimental data. In addition, the evaluation of adsorption kinetics demonstrated that the pseudo-second-order Lagergren model predicted the results more precisely. The amount of asphaltene adsorption for Fe₃O₄-MOF MNPs was higher than that for Fe₃O₄ MNPs. These results recommend the application of MOF as an appropriate and effective coating for enhancing asphaltene adsorption.     

A facile two-step modifying process for preparation of poly(SStNa)-grafted Fe3O4/SiO2 particles

This article reports the synthesis of the poly(sodium 4-styrenesulfonate)-grafted Fe₃O₄/SiO₂ particles via two steps. The first step involved magnetite nanoparticles (Fe₃O₄) homogeneously incorporated into silica spheres using the modified Stöber method. Second, the modified silica-coated Fe₃O₄ nanoparticles were covered with the outer shell of anionic polyelectrolyte by surface-initiated atom transfer radical polymerization. The resulted composites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive microscopy (EDS), Fourier transform-infrared (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and vibration sample magnetometer (VSM). The XRD results indicated that the surface modified Fe₃O₄ nanoparticles did not lead to phase change compared with the pure Fe₃O₄. TEM studies revealed nanoparticles remained monodisperse. The detection of sulfur and sodium signals was a convincing evidence that sodium 4-styrenesulfonate was grafted onto the surface of the magnetic silica in XPS analysis. Finally, super-paramagnetic properties of the composite particles, and the ease of modifying the surfaces may make the composites of important use in mild separation, enzyme immobilization, etc.     

Amperometric Immunosensor Based on Gold Nanoparticles/Fe3O4-FCNTs-CS Composite Film Functionalized Interface for Carbofuran Detection

In this paper, a novel amperometric immunosensor for the determination of carbofuran based on gold nanoparticles (GNPs), magnetic Fe₃O₄ nanoparticles-functionalized multiwalled carbon nanotubes-chitosan (Fe₃O₄-FCNTs-CS), and bovine serum albumin (BSA) composite film was proposed. First, GNPs were immobilized onto the glassy carbon electrode (GCE) surface, and then the magnetic Fe₃O₄ nanoparticles mixed with chitosan-functionalized multiwall carbon nanotubes (CS-FCNTs) homogeneous composite (CS-FCNTs-Fe₃O₄) was immobilized onto the GNPs layer by electrostatic interactions between amino groups of CS and GNPs. Because chitosan (CS) contains many amino groups, it can absorb more antibodies. FCNTs have high surface area, high electrical conductivity, and it can enhance the electron transfer rate; Magnetite (Fe₃O₄) nanoparticles can provide a favorable microenvironment for biomolecules immobilization due to their good biocompatibility, strong superparamagnetic property, and low toxicity; and GNPs possess high surface-to-volume reaction, stability, and high conductivity. Gold Nanoparticles/Fe₃O₄-FCNTs-CS composite film was constructed onto the GCE surface, which had significant synergistic effects toward immunoreaction signal amplification. The stepwise assembly process was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. Under the optimal conditions, the current response was proportional to the concentration of carbofuran ranging from 1.0 ng/mL to 100.0 ng/mL and from 100.0 ng/mL to 200 µg/mL with the detection limit 0.032 ng/mL. The proposed immunosensor exhibited good accuracy, high sensitivity, and stability, and it can be used for detection of carbofuran pesticide.     

Facile synthesis of multifunctional attapulgite/Fe3O4/polyaniline nanocomposites for magnetic dispersive solid phase extraction of benzoylurea insecticides in environmental water samples

In this study, the superparamagnetic attapulgite/Fe₃O₄/polyaniline (ATP/Fe₃O₄/PANI) nanocomposites were successfully synthesized by a one-pot method. Fe (III) was applied as both the oxidant for the oxidative polymerization of aniline and the single iron source of Fe₃O₄ formed by the redox reaction between aniline and Fe (III). The ATP/Fe₃O₄/PANI was used as sorbent for magnetic dispersive solid phase extraction (MDSPE) of benzoylurea insecticides (BUs) in environmental water samples. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X Ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM), and vibrating sample magnetometry. Various experimental parameters affecting the ATP/Fe₃O₄/PANI-based MDSPE procedure, including the composition of the nanocomposite sorbents, amount of ATP/Fe₃O₄/PANI nanocomposites, vortex time, pH, and desorption conditions were investigated. Under the optimal conditions, a good linearity was observed for all target analytes, with correlation coefficients (r²) ranging from 0.9985 to 0.9997; the limits of detection (LOD) were in the range of 0.02–0.43 μg L⁻¹, and the recoveries of analytes using the proposed method ranged between 77.37% and 103.69%. The sorbents exhibited an excellent reproducibility in the range of 1.52–5.27% in extracting the five target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.78–6.86% and 1.66–8.41%, respectively. Finally, the proposed ATP/Fe₃O₄/PANI-based MDSPE method was successfully applied to analyze river water samples by rapid preconcentration of BUs.     

静电自组装方法合成的具有多孔三维网络结构的Fe3O4/石墨烯复合材料作为高性能锂离子电池负极材料

采用静电自组装方法,分两步合成Fe（OH）₃/GO前驱体（GO：氧化石墨烯）,再通过水热反应和600 ℃高纯氮气气氛下煅烧,获得了Fe₃O₄/石墨烯复合材料. 通过X射线衍射（XRD）、扫描电镜（SEM）、高分辨透射电镜（HRTEM）、拉曼（Raman）光谱等多种分析,发现该复合材料具有三维多孔石墨烯网络结构. 把合成的这种Fe₃O₄/石墨烯复合材料作为锂离子电池负极材料,电化学测试结果表明其具有优良的电化学性能：首次放电容量为1390 mAh·g^-1,50次循环后容量为819 mAh·g^-1. 通过对比实验表明,三维石墨烯网络结构的形成对复合材料的电化学循环稳定性起着关键作用.