Iron Oxide Nanoparticles: Biosynthesis,Magnetic Behavior,Cytotoxic Effect

Iron oxide nanoparticles have attracted much attention because of their superparamagnetic properties and their potential applications in many fields such as magnetic storage devices, catalysis, sensors, superparamagnetic relaxometry (SPMR), and high-sensitivity biomolecule magnetic resonance imaging (MRI) for medical diagnosis and therapeutics. In this study, iron oxide nanoparticles (Fe₂O₃ NPs) have been synthesized using a taranjabin (camelthorn or persian manna) aqueous solution. The synthesized Fe₂O₃ NPs were identified through powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), field energy scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX), vibrating-sample magnetometer (VSM) and Raman technics. The results show that the nanoparticles have a hexagonal structure with 20 to 60 nm in size. The cytotoxic effect of the synthesized nanoparticles has been tested upon application against lung cancer cell (A549) lines. It was found that there is no cytotoxic activity at lower concentrations of 200 μg/mL. The ability of the synthesized nanoparticles for lead removal in wastewaters was tested. Results show that highest concentration of adsorbent (50 mg/L) has maximum removal efficiency (96.73 %). So, synthesized Fe₂O₃ NPs can be a good candidate to use as heavy metals cleaner from contaminated waters.     

磁载光催化剂Fe3O4/C/TiO2的制备及对三氯苯酚的降解

以FeCl₃为铁源, 葡萄糖为碳源, 钛酸四丁酯为钛源, 采用水热法制备了磁载光催化剂Fe₃O₄/C/TiO₂, 用TEM、EDX、VSM、XRD和IR对Fe₃O₄/C/TiO₂的粒径、形貌和物相等进行了表征。研究了该催化剂对三氯苯酚的降解性能, 探讨了其重复使用的可能性, 用荧光光谱法推测了可能的反应机理。结果表明该材料结合了光催化与可再生的优点, 1 g·L^-1 Fe₃O₄/C/TiO₂在18 W紫外灯下, 50 min内可将三氯苯酚降解97.9%以上, 6次循环使用后降解率仍保持在95.1%, 降解过程中有羟基自由基生成。     

Copper-based Schiff Base Complex Immobilized on Core-shell Fe3O4@SiO2 as a magnetically recyclable and highly efficient nanocatalyst for green synthesis of 2-amino-4H-chromene derivatives

Fe₃O₄-supported copper (II) Schiff-Base complex has been synthesized through post-modification with 1,3-phenylenediamine followed by further post-modification with salicylaldehyde and coordination with Cu(II) ion. The resulted Fe₃O₄@SiO₂-imine/phenoxy-Cu(II) magnetic nanoparticles (MNPs) were characterized by various techniques including SEM, TEM, XRD, XPS, EDX, VSM, FT-IR, and ICP. The catalytic activity as a magnetically recyclable heterogeneous catalyst for one-pot, three-component synthesis of 2-amino-4H-chromene derivatives was examined. The catalyst is efficient in the reaction and can be recovered by magnetic separation and recycled several times without significant loss in the catalytic activity.     

Anchoring of Cu (II)-Schiff base complex on magnetic mesoporous silica nanoparticles: catalytic efficacy in one-pot synthesis of 5-substituted-1H-tetrazoles,antibacterial activity evaluation and immobilization of α-amylase

Magnetic mesoporous silica nanocomposite, Fe₃O₄@MCM-41, was prepared and functionalized with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPS). Then Schiff base grafted nanoparticles were synthesized by the condensation of 5,5'-methylene bis (salicylaldehyde) and then benzhydrazide with Fe₃O₄@MCM-41-AEAPS. Finally, by adding Cu (CH₃COOH)₂.H₂O, the magnetic nanoparticles (MNPs) functionalized with Cu (II) Schiff base complex were synthesized. The new organic–inorganic hybrid nanocomposite was characterized by FT-IR, PXRD, AAS, BET, TGA, VSM, FE-SEM, HRTEM and EDX techniques. Then, the performance of this copper based magnetic nanocatalyst was investigated for the synthesis of 5-substituted 1H-tetrazole derivatives using one pot three-component reactions of various aldehydes, hydroxyl amine hydrochloride and sodium azide. The catalyst can be easily isolated from the reaction mixture by applying an external magnet and reused for at least 5 times without significant loss in catalytic activity. Also, the antibacterial activity of the streptomycin loaded magnetic nanoparticles against Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria in the presence and absence of a magnetic field were studied. Results revealed that when these materials exposed to the magnetic field, bacteriostatic activity of nanocomposites was increased. Furthermore, the enzyme immobilization ability of the synthesized compounds was investigated and the results showed that these nanoparticles efficiently immobilized amylase enzyme.     

SiO2 coated Fe3O4 magnetic nanoparticle dispersed multiwalled carbon nanotubes based amperometric glucose biosensor

A new type of amperometric glucose biosensor based on silicon dioxide coated magnetic nanoparticle decorated multiwalled carbon nanotubes (Fe₃O₄@SiO₂/MWNTs) on a glassy carbon electrode (GCE) has been developed. MWNTs have been synthesized by catalytic chemical vapour decomposition (CCVD) of acetylene over rare earth (RE) based AB₃ alloy hydride catalyst. The as-grown MWNTs have been purified and further functionlized. Functionalized MWNTs have been decorated with magnetic Fe₃O₄ nanoparticles which have been uniformly coated with biocompatible SiO₂ using a simple chemical reduction method. The characterization of magnetic nanoparticle modified MWNTs have been done by X-ray diffraction (XRD), Fourier transform infra red spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM), energy dispersive X-ray analysis (EDX) and UV-vis spectroscopy. Amperometric biosensor has been fabricated by the deposition of glucose oxidase (GOD) over Nafion-solubilized Fe₃O₄@SiO₂/MWNTs electrode. The resultant bioelectrode retains its biocatalytic activity and offers fast and sensitive glucose quantification. The performance of the biosensor has been studied using cyclic voltammetry and amperometry and the results have been discussed. The fabricated glucose biosensor exhibits a linear response from 1 μM to 30 mM with an excellent detection limit of 800 nM indicating the potential applications in food industries.     

A study of magnetic,antibacterial and antifungal behaviour of a novel gold anchor of polyaniline/itaconic acid/Fe3O4 hybrid nanocomposite: Synthesis and characterization

The objective of the present investigation is to fabricate the gold anchor polyaniline (PANI) based nanocomposites which is prepared using itaconic acid (IA) with Fe₃O₄ by the simple polymerization reaction. The developed multi responsive antibacterial magnetic polymeric composite is represented as Au@PANI–IA–Fe₃O₄. Further, the chemical structure, thermal and magnetic properties such as FT-IR, TGA/DTA, and VSM analysis are studied. The TEM and SEM/EDX are used to find the shape and composition of gold nanoparticles. The enhanced magnetic properties of ferrite composite are exhibited and the antibacterial properties are determined using E. coli (gram -ve) and S. aureus (gram +ve) bacteria’s. The results of biological properties such as antifungal and antimicrobial are also studied critically conferred. Based on the experimental results, the fabrication method of Au@/PANI/IA/Fe₃O₄ magnetic nanocomposites, and the relationship between the structure and biological properties are discussed in detail.     

Oxoperoxo tungsten(VI) complex immobilized on Schiff base-modified Fe3O4 magnetic nanoparticles as a heterogeneous catalyst for oxidation of alcohols with hydrogen peroxide

Oxoperoxo tungsten(VI) complex immobilized on Schiff base-modified Fe₃O₄ super paramagnetic nanoparticles were synthesized and appropriately characterized using FT-IR, XRD, SEM, TEM, EDX, BET, and VSM analysis. The synthesized nanoparticles efficiently catalyzed oxidation of benzylic alcohols with H₂O₂ as oxidant in high yields, with high to excellent selectivity. The catalyst can be recovered using an external magnetic field and recycled for subsequent oxidation reactions without any appreciable loss of efficiency. The simple preparation, high activity, excellent selectivity, and simple recoverability of the catalyst are advantageous.     

A novel green synthesis of Fe3O4 magnetic nanorods using Punica Granatum rind extract and its application for removal of Pb(II) from aqueous environment

We described a novel and eco-friendly approach to remove toxic heavy metal of Pb(II) by using dimercaptosuccinic acid (DMSA) anchored Fe₃O₄ magnetic nanorods (MNRs) which were synthesized via facile method utilizing Punica Granatum rind extract which was a non toxic waste material. The DMSA@Fe₃O₄ MNRs were characterized by X-ray diffraction (XRD), Fourier transformed infrared analysis (FT-IR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption and desorption techniques, and vibrating sample magnetometer (VSM). These DMSA@Fe₃O₄ MNRs have been used for the removal of Pb(II) from aqueous solution. The adsorption isotherm data fitted well with Langmuir isotherm and Freundlich model, the monolayer adsorption capacity was found to be 46.18 mg/g at 301 K. The experimental kinetic data fitted very well with the pseudo-second-order model. The results indicate that the biogenic synthesized DMSA@Fe₃O₄ MNRs act as significant adsorbent material for removal of Pb (II) from aqueous environment.     

Synthesis of a novel and reusable biological urea based acidic nanomagnetic catalyst: Application for the synthesis of 2‐amino‐3‐cyano pyridines via cooperative vinylogous anomeric based oxidation

In the current study, a novel and reusable biological urea based nano magnetic catalyst namely Fe₃O₄@SiO₂@(CH₂)₃‐urea‐benzimidazole sulfonic acid was designed and synthesized. The structure of the titled catalyst was fully characterized using several skills including Fourier transform infrared (FT‐IR) spectroscopy, energy dispersive X‐ray (EDX) analysis, X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo gravimetric analysis/differential thermal analysis (TG/DTG) and vibrating sample magnetometer (VSM). Then, the catalytic performance of Fe₃O₄@SiO₂@(CH₂)₃‐urea‐benzimidazole sulfonic acid was successfully inspected towards the multicomponent synthesis of 2‐amino‐3‐cyano pyridine derivatives through a vinylogous anomeric based oxidation pathway.     

Preparation of magnetic separable CoFe2O4/PAC composite and the adsorption of bisphenol A from aqueous solution

CoFe₂O₄/PAC composite adsorbent has been prepared via an immersing-calcination process, using ethylene diamine tetraacetic acid (EDTA) and citric acid (CIT) ligands containing sol as the CoFe₂O₄ precursor. The microstructure characterization and magnetic property of as-prepared sample were performed by means of XRD and VSM measurements. The adsorption kinetics, isotherms and thermodynamic process toward Bisphenol A molecules (BPA, which is considered as one of the typical endocrine disrupting chemicals) occurred on as-prepared magnetic adsorbent which were investigated by the pseudo-second order kinetic/intraparticle models, the Langmuir/Freundlich adsorption isothermal models and basic chemical thermodynamics principles, respectively.     

Supported silver nanoparticles over alginate-modified magnetic nanoparticles: Synthesis,characterization and treat the human lung carcinoma

This article displays synthesis of Silver nanoparticles (Ag NPs) decorated on sodium alginate covered magnetite (Fe₃O₄/Alg-Ag NPs) nanocomposite. Sodium alginate shell as a natural anionic polysaccharide on Fe₃O₄ microparticles core acted as a stabilizing agent for the reduction of Ag(I) ions into Ag NPs. The structural features of the synthesized nanocomposite were investigated by fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopes (FE-SEM), transmission electron microscopes (TEM), energy-dispersive X-ray spectroscopy (EDX) and vibrating-sample magnetometer (VSM) studies and inductively coupled plasma-optical emission spectroscopy (ICP-OES). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used on common lung cancer cell lines i.e., NCI-H1975, NCI-H1563, and NCI-H1299 to survey the cytotoxicity and anti-lung cancer effects of the synthesized nanocomposite. The synthesized nanocomposite had very low cell viability and high anti-lung cancer activities dose-dependently against NCI-H1975, NCI-H1563, and NCI-H1299 cell lines without any cytotoxicity on the normal cell line (Human umbilical vein endothelial cells (HUVECs)). To determine the antioxidant properties of the synthesized nanocomposite, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test was used in the presence of butylated hydroxytoluene as the positive control. The synthesized nanocomposite inhibited half of the DPPH molecules in the concentration of 194 µg/mL. Maybe significant anti-human lung cancer potentials of the synthesized nanocomposite against common human lung cancer cell lines are linked to their antioxidant activities.     

磁性壳聚糖/Fe3O4/氧化石墨烯吸附剂的制备及其多染料吸附性能

为了提高壳聚糖的多染料吸附性能并使其便于固液分离,采用共沉淀法制备了壳聚糖、磁铁矿纳米颗粒、氧化石墨烯复合磁性吸附剂(CS/Fe₃O₄/GO)。系统的结构表征显示,CS包覆的Fe₃O₄磁性纳米颗粒均匀地分布在GO的表面。CS/Fe₃O₄/GO具有高达42.5 emu·g-1的室温铁磁性,因此可在外加磁场中实现高效固液分离。研究表明,CS/Fe₃O₄/GO对亚甲基蓝(MB)、甲基橙(MO)和刚果红(CR)等多种染料具有良好的吸附性能,溶液的pH、初始浓度和吸附时间对其多染料吸附性能具有显著影响。在最佳条件下,CS/Fe₃O₄/GO对MB、MO和CR的吸附量分别达到210.6、258.6和308.9 mg·g-1。CS/Fe₃O₄/GO具有优异的循环利用性能,经5次循环后仍能保留90%以上的原始吸附量。采用吸附等温线和吸附动力学对...     

Fe3O4/MIL‐101(Fe) nanocomposite as an efficient and recyclable catalyst for Strecker reaction

A highly porous metal‐organic framework, MIL‐101(Fe), was prepared by a solvothermal method in the presence of amino‐modified Fe₃O₄@SiO₂ nanoparticles, in order to achieve Fe₃O₄/MIL‐101(Fe) nanocomposite, which was characterized by XRD, FT‐IR, SEM, TEM, BET, and VSM. This hybrid magnetic nanocomposite was employed as heterogeneous catalyst for α‐amino nitriles synthesis through three‐component condensation reaction of aldehydes (ketones), amines, and trimethylsilyl cyanide in EtOH, at room temperature. The recoverability and reusability was admitted for the heterogeneous magnetic catalyst; no significant reduction of catalytic activity was observed even after five consecutive reaction cycles.     

Picolinimidoamide-Cu(II) complex anchored on Fe3O4@SiO2 core–shell magnetic nanoparticles: an efficient reusable catalyst for click reaction

A Cu(II) complex supported on Fe₃O₄@SiO₂ core–shell magnetic nanoparticles (MNPs) was prepared and characterized by FT-IR, XRD, SEM, EDX, TEM, VSM, TGA, and AAS analysis. The load of Cu on picolinimidoamide ligand anchored on Fe₃O₄@SiO₂ core–shell MNPs was determined as 1.22, 1.54, and 1.70 wt% using AAS, EDX and TGA analyses, respectively. Synthesized Cu(II) complex on Fe₃O₄@SiO₂ MNPs efficiently catalyzed a click reaction between alkyl halides, alkynes, and sodium azide to synthesize corresponding triazoles in high to excellent yields. The catalyst was recovered using an external magnetic field, and recycled for subsequent reactions without substantial loss of efficiency.     

One-Step Preparation of Chitosan-Based Magnetic Adsorbent and Its Application to the Adsorption of Inorganic Arsenic in Water

Chitosan is a kind of biodegradable natural polysaccharide, and it is a very promising adsorber material for removing metal ions from aqueous solutions. In this study, chitosan-based magnetic adsorbent CMC@Fe₃O₄ was synthesized by a one-step method using carboxymethyl chitosan (CMC) and ferric salts under relatively mild conditions. The Fe₃O₄ microspheres were formed and the core–shell structure of CMC@Fe₃O₄ was synthesized in the meantime, which was well characterized via SEM/TEM, XRD, VSM, FT-IR, thermo gravimetric analysis (TGA), XPS, size distribution, and zeta potential. The effects of initial arsenic concentration, pH, temperature, contact time, and ionic strength on adsorption quantity of inorganic arsenic was studied through batch adsorption experiments. The magnetic adsorbent CMC@Fe₃O₄ displayed satisfactory adsorption performance for arsenic in water samples, up to 20.1 mg/g. The optimal conditions of the adsorption process were pH 3.0, 30−50 °C, and a reaction time of 15 min. The adsorption process can be well described by pseudo-second-order kinetic model, suggesting that chemisorption was main rate-controlling step. The Langmuir adsorption model provided much higher correlation coefficient than that of Freundlich adsorption model, indicating that the adsorption behavior is monolayer adsorption on the surface of the magnetic adsorbents. The above results have demonstrated that chitosan-based magnetic adsorbent CMC@Fe₃O₄ is suitable for the removal of inorganic arsenic in water.     

磁性Fe_2O_3/Au/Ag复合纳米粒子的制备及其富集作用研究

利用种子生长法制备了磁性Fe2O3/Au/Ag复合纳米粒子,采用UV-vis和SEM对其光学性质以及表面结构的变化进行了表征.通过调节硝酸银的用量,制备了一系列具有不同Ag壳层厚度和表面结构的双金属外壳纳米粒子.以苯硫酚(TP)为探针分子,研究了不同Ag壳厚度的磁性纳米粒子的表面增强拉曼散射(SERS)活性.结果表明其SERS活性与表面结构的改变有关,在同时出现Ag和Au光学性质的Fe2O3/Au/Ag复合纳米粒子表面可观察到最强的SERS效应,这与表面的针孔效应以及Ag和Au之间的耦合增强作用有关.考察了Fe2O3/Au/Ag复合纳米粒子的磁富集作用,并利用SERS原位监测磁富集溶液中低浓度TP的能力,研究结果表明通过磁富集可提高SERS检测限,并且Fe2O3/Au/Ag的磁富集能力较Fe2O3/Au弱,但前者SERS信号较强.     

Research on WPU‐RGO/ATP‐Fe3O4/chitosan composites with excellent electrical and magnetic properties

First, attapulgite‐Fe₃O₄ magnetic filler (ATP‐Fe₃O₄) was prepared by using a chemical precipitation method. Subsequently, graphite oxide (GO) was prepared through Hummer method, and then reduced GO (RGO) was prepared through GO reduced by chitosan (CS). Finally, a series of WPU‐RGO/ATP‐Fe₃O₄/CS composites were prepared by introduced RGO/ATP‐Fe₃O₄/CS to waterborne polyurethane. The structure and properties were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X‐ray diffraction (XRD), vibrating sample magnetometry (VSM), thermogravimetric analysis TGA, conductivity test, and tensile test. The experimental results indicated that thermal stability and tensile strength of nanocomposites were improved with the increase of the content of RGO/ATP‐Fe₃O₄/CS. Meanwhile, with the increase of the RGO/ATP‐Fe₃O₄/CS content, the electrical and magnetic properties of WPU‐RGO/ATP‐Fe₃O₄/CS composites were improved. When the content of RGO/ATP‐Fe₃O₄/CS was 8 wt%, the electrical conductivity and the saturation magnetic strength of WPU‐RGO/ATP‐Fe₃O₄/CS composites were 3.1 × 10^?7 S·cm^?1 and 1.38 emu/g, respectively. WPU‐RGO/ATP‐Fe₃O₄/CS composites have excellent electrical and magnetic properties.     

Immobilization of palladium nanoparticles on ionic liquid-triethylammonium chloride functionalized magnetic nanoparticles: As a magnetically separable,stable and recyclable catalyst for Suzuki-Miyaura cross-coupling reactions

A facile procedure was applied to successfully synthesize novel Pd nanoparticles immobilized on triethanolamine-functionalized magnetic nanoparticles [Fe₃O₄/IL/Pd]. Diverse characterizations (HR-TEM, XRD, FT-IR, TGA, EDX, FE-SEM, ICP, XPS and VSM) were carried out to identify intrinsic traits of the nanoparticles. At room temperature, Fe₃O₄/IL/Pd demonstrated high catalytic activity toward Suzuki-Miyaura cross-coupling reactions in aqueous solution. Based on the results, Fe₃O₄/IL/Pd acted as zwitterionic IL-type heterogeneous catalyst, which could be separated from the reaction mixture, conveniently. Moreover, it exhibited excellent recyclability for at least eight cycles without considerable loss of its activity.     

磁性壳聚糖/Fe3O4/氧化石墨烯吸附剂的制备及其多染料吸附性能

为了提高壳聚糖的多染料吸附性能并使其便于固液分离,采用共沉淀法制备了壳聚糖、磁铁矿纳米颗粒、氧化石墨烯复合磁性吸附剂(CS/Fe₃O₄/GO)。系统的结构表征显示,CS包覆的Fe₃O₄磁性纳米颗粒均匀地分布在GO的表面。CS/Fe₃O₄/GO具有高达42.5 emu·g^-1的室温铁磁性,因此可在外加磁场中实现高效固液分离。研究表明,CS/Fe₃O₄/GO对亚甲基蓝(MB)、甲基橙(MO)和刚果红(CR)等多种染料具有良好的吸附性能,溶液的pH、初始浓度和吸附时间对其多染料吸附性能具有显著影响。在最佳条件下,CS/Fe₃O₄/GO对MB、MO和CR的吸附量分别达到210.6、258.6和308.9 mg·g^-1。CS/Fe₃O₄/GO具有优异的循环利用性能,经5次循环后仍能保留90%以上的原始吸附量。采用吸附等温线和吸附动力学对CS/Fe₃O₄/GO的多染料吸附性能进行了拟合分析,并详细讨论了其吸附机理。     

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.