Fe3O4 MNPs Research Articles

Nano-Fe3O4-Promoted Five-Component Domino Reactions for the Green Synthesis of Novel Benzo[a]phthalazino[2′,3′:1,2]pyrazolo[3,4-c]phenazines in PEG-400 as an Efficient Eco-Friendly Reaction Medium

ABSTRACTNovel benzo[a]phthalazino[2′,3′:1,2]pyrazolo[3,4-c]phenazines containing both biologically active benzophenazine and pyrazolophthalazine templates are synthesized using a single-pot, five-component reaction involving 2-hydroxynaphthalene-1,4-dione, aromatic 1,2-diamines, hydrazine hydrate, phthalic anhydride, and benzaldehydes catalyzed by magnetic iron(III) oxide nanoparticles (Fe3O4 MNPs) in polyethylene glycol (PEG-400) as an inexpensive, non-toxic, and effective medium at 70°C. In this domino protocol, seven bonds (C−C, 4C−N, 2C=N) and three new rings are efficiently formed and this new green process provides the salient features such as the following: operational simplicity, high yields, low cost, reusability of Fe3O4 MNPs and PEG-400, absence of any tedious workup or purification, and avoidance of hazardous or toxic reagents/catalysts/solvents.

Polysaccharide-based magnetically responsive polyelectrolyte hydrogels for tissue engineering applications

Polysaccharide-based bionanocomposite hydrogels with functional nanomaterials were used in biomedical applications. Self-organization of xanthan gum and chitosan in the presence of iron oxide magnetic nanoparticles (Fe3O4 MNPs) allowed us to form magnetically responsive polyelectrolyte complex hydrogels (MPECHs) via insitu ionic complexation using D-(+)-glucuronic acid δ-lactone as a green acidifying agent. Characterization confirmed the successful formation of (and structural interactions within) the MPECH and good porous structure. The rheological behavior and compressive properties of the PECH and MPECH were measured. The results indicated that the incorporation of Fe3O4 MNPs into the PECH greatly improved mechanical properties and storage modulus (G'). In vitro cell culture of NIH3T3 fibroblasts on MPECHs showed improvements in cell proliferation and adhesion in an external magnetic field relative to the pristine PECH. The results showed that the newly developed MPECH could potentially be used as a magnetically stimulated system in tissue engineering applications.

An Efficient and Green Stereoselective Synthesis of Functionalized 3-Indol-3-yl-oxoindolin-3-yl-3-acrylates via Nano-Fe3O4-Promoted One-Pot Four-Component Domino Reactions

ABSTRACTMagnetic iron(III) oxide nanoparticles (Fe3O4 MNPs) have been used as a readily available, highly efficient, and recyclable catalyst for the green and stereoselective synthesis of novel functionalized 3-indol-3-yl-oxoindolin-3-yl-3-acrylates from a one-pot, two-step, four-component reaction of arylamines, alkyl propiolates, isatin, and indole in EtOH under reflux conditions in good yields. The domino environmentally friendly methodology with excellent green chemistry credentials, such as using the low loading of reusable, nontoxic, easy to handle catalyst, shorter reaction time, avoidance of hazardous organic solvents, and straightforward workup (the catalyst can be easily separated from the reaction mixture by an external magnet), may find a wide range of applications.

Highly sensitive fluorometric determination of oxytetracycline based on carbon dots and Fe3O4 MNPs

In this paper, a novel, selective and eco-friendly biosensor has been fabricated and applied for sensitive detection of antibiotic oxytetracycline (OTC). This fluorescent biosensor was based on carbon quantum dots (CDs), H2O2 and Fe3O4 magnetic nanoparticles (Fe3O4 MNPs). Herein, we firstly demonstrated that the fluorescence of CDs decreased apparently in the presence of OTC, H2O2 and Fe3O4 MNPs. The fluorescence quenching of CDs not only is caused by the hydroxyl radical produced from the Fenton reaction and complexation of Fe3O4 MNPs with OTC, but also might be related to the inner filter effect (IFE) between CDs and OTC, which improved the selectivity and sensitivity of the fabricated biosensor. Under the optimal experiment conditions, the relative fluorescence intensity of the CDs decreased linearly with the increasing concentration of OTC from 25nM to 1.75μM. The detection limit of the fabricated biosensor on OTC was 9.5nM at a signal-to-noise ratio of 3. Compared with other current protocols, the method described here displayed a few advantages including simplicity, low cost and rapid detection. The precision and reproducibility of the proposed sensor were also acceptable Significantly, the practicality of this sensitive sensor for OTC detection in drugs was further validated, revealing the advantages of high simplicity, sensitivity and selectivity. Hence, the developed biosensor might provide a useful and practical tool for OTC determination and related food safety analysis and clinical diagnosis.

Adsorption of asphaltene from crude oil by applying polythiophene coating on Fe3O4 nanoparticles

ABSTRACTThe objective of the present study was to investigate the potential use of applying polythiophene coating on magnetic Fe3O4 nanoparticles for the enhancement of asphaltene adsorption. Two stages of experimental were conducted. In the first stage, the ability of coated nanoparticles for asphaltene adsorption in synthetic asphaltene-toluene solution was evaluated. The effects of parameters such as nanoparticles concentration, initial concentration of asphaltene, and temperature were studied. In the second stage, the performance of the coated nanoparticles for the adsorption of asphaltene from crude oil was investigated under atmospheric pressure and a pressure-volume-temperature (PVT) apparatus was utilized for simulated reservoir conditions. Fe3O4 and Fe3O4-PT MNPs were synthesized using an effective co-precipitation method. The results of the first-stage tests indicated that the maximum adsorption capacity values for Fe3O4 and Fe3O4-PT MNPs were 0.79 and 1.09 mg m−2, respectively. The optimum value of nanoparticles concentration was approximately determined as 10 g L−1. According to the adsorption isotherms and kinetics, the Langmuir and pseudo-second-order Lagergren models were consistent with the experimental data, respectively. The average adsorption efficiencies for Fe3O4-PT and Fe3O4 MNPs were 78.98 and 65.94%, respectively. The results of the performed experiments on crude oil showed that Fe3O4-PT MNPs could adsorb asphaltenes from crude oil in a similar trend as synthetic asphaltene-toluene solution.

An efficient synthesis and cytotoxic activity of 2‐(4‐chlorophenyl)‐1H–benzo[d]imidazole obtained using a magnetically recyclable Fe3O4 nanocatalyst‐mediated white tea extract

A simple and efficient procedure has been developed for the synthesis of biologically relevant 2‐substituted benzimidazoles through a one‐pot condensation of o‐phenylenediamines with aryl aldehydes catalysed by iron oxide magnetic nanoparticles (Fe3O4 MNPs) in short reaction times with excellent yields. In the present study, Fe3O4 MNPs synthesized in a green manner using aqueous extract of white tea (Camelia sinensis) (Wt‐Fe3O4 MNPs) were applied as a magnetically separable heterogeneous nanocatalyst to synthesize 2‐(4‐chlorophenyl)‐1H–benzo[d]imidazole which has potential application in pharmacology and biological systems. Fourier transform infrared and NMR spectroscopies were used to characterize the 2‐(4‐chlorophenyl)‐1H–benzo[d]imidazole. In vitro cytotoxicity studies on MOLT‐4 cells showed a dose‐dependent toxicity with non‐toxic effect of 2‐(4‐chlorophenyl)‐1H–benzo[d]imidazole, up to a concentration of 0.147 µM. The green synthesized Wt‐Fe3O4 MNPs as recyclable nanocatalyst could be used for further research on the synthesis of therapeutic materials, particularly in nanomedicine, to assist in the treatment of cancer.

A capable cobalt nano‐catalyst for the N‐formylation of various amines and its biological activity studies

The Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) were modified with 1,10‐phenanthroline‐5,6‐diol and the relevant Co complex (Fe3O4@Phendiol@Co) synthesized as a nano‐magnetic heterogeneous catalyst to be used for the N‐formylation of various amines at room temperature under solvent‐free conditions. Also, in order to find the better concept of the catalyst role, the N‐formylation reaction was carried out by the use of ultrasound irradiation in the absence of the Co nano‐catalyst and the results were compared. The catalyst characterized by different methods such as the elemental analysis (CHN), ICP, FT‐IR, XRD, EDX, SEM, TEM, TG‐DTA, VSM and XPS. In addition, the antioxidant and the antibacterial activities of the Fe3O4@Phendiol@Co nano‐catalyst and its Phendiol ligand were in vitro screened by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical scavenging and disc diffusion methods. Results showed that they possess strong antioxidant activity (IC50; 0.182 ± 0.006 mg/ml) and good antibacterial potential in comparison to standards.

Synthesis and characterization of cobalt-supported catalysts on modified magnetic nanoparticle: Green and highly efficient heterogeneous nanocatalyst for selective oxidation of ethylbenzene, cyclohexene and oximes with molecular oxygen

In this study, a new supported cobalt nanocatalyst has been described. The Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) modified by SiO2/aminopropyl trimethoxy silane/cyanuric chloride (Fe3O4@SiO2-APTMS/CC) utilized for anchoring metformin-cobalt complex (Fe3O4 Ms@SiO2-APTMS/CC/Met@Co(II)). The structure of novel complex well defined by elemental analysis, ICP, AAS, BET, FT-IR, EDX, SEM, TEM, DLS, XRD, TG-DTG, VSM and XPS. The catalytic efficiency of the synthesized cobalt nanocatalyst was studied in the oxidation of ethylbenzene (EB), cyclohexene (CYHE) and various oximes using molecular oxygen as ecofriendly oxidant and high catalytic activity and selectivity toward oxidation is observed. Selective aerobic oxidation of EB and CYHE and various oximes catalyzed by the cobalt nanocatalyst without any reducing agent by using N-hydroxyphthalimide (NHPI), gave acetophenone (AcPO), 2-cyclohexene-1-one and corresponding carbonyl compounds respectively, as major products. To achieve high level of efficiency of heterogeneous nanocatalyst, various parameters such as the ratio and amount of nanocatalyst/NHPI, reaction time, temperature and solvents were evaluated. The easily preparation from inexpensive and commercially available reagent, thermal stability, suitable performance in reusability, high efficiency and selectivity in oxidation reactions, short reaction time, easy recovery and separation from reaction mixture, are advantages of this novel catalyst.

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

ABSTRACTIn 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.

An efficient method for synthesis of some heterocyclic compounds containing 3-iminoisatin and 1,2,4-triazole using Fe3O4 magnetic nanoparticles

ABSTRACT1,2,4-triazole derivatives were prepared by reaction of thiocarbohydrazide and some esters in 60% ethanol. Condensation of 1,2,4-triazole derivatives with isatin gave Schiff bases of 3-iminoisatin derivatives. Reaction of malonic or succinic acid dihydrazide with isatin lead to formation of N,N'-bis-(3-imino-1,3-dihydro-indolyl-2-one)-malonamide 8a and N,N'-bis-(3-imino-1,3-dihydro-indolyl-2-one)succinamide 8b in good yields under mild reaction conditions. These reactions are catalyzed by Fe3O4 MNPs. The chemical structures were confirmed by Fourier transform-infrared, 1H-NMR, 13C-NMR, gas chromatography-mass spectrometry spectroscopy, and elemental analysis.

Gallium-68 Labeled Iron Oxide Nanoparticles Coated with 2,3-Dicarboxypropane-1,1-diphosphonic Acid as a Potential PET/MR Imaging Agent: A Proof-of-Concept Study.

The aim of this study was to develop a dual-modality PET/MR imaging probe by radiolabeling iron oxide magnetic nanoparticles (IONPs), surface functionalized with water soluble stabilizer 2,3-dicarboxypropane-1,1-diphosphonic acid (DPD), with the positron emitter Gallium-68. Magnetite nanoparticles (Fe3O4 MNPs) were synthesized via coprecipitation method and were stabilized with DPD. The Fe3O4-DPD MNPs were characterized based on their structure, morphology, size, surface charge, and magnetic properties. In vitro cytotoxicity studies showed reduced toxicity in normal cells, compared to cancer cells. Fe3O4-DPD MNPs were successfully labeled with Gallium-68 at high radiochemical purity (>91%) and their stability in human serum and in PBS was demonstrated, along with their further characterization on size and magnetic properties. The ex vivo biodistribution studies in normal Swiss mice showed high uptake in the liver followed by spleen. The acquired PET images were in accordance with the ex vivo biodistribution results. Our findings indicate that 68Ga-Fe3O4-DPD MNPs could serve as an important diagnostic tool for biomedical imaging.

Fabrication of reduced glutathione functionalized iron oxide nanoparticles for magnetic removal of Pb(II) from wastewater

Abstract In this study, a novel nanoadsorbent (Fe3O4 SiO2-GSH MNPs) based on iron oxide magnetic nanoparticles (Fe3O4 MNPs), coated with SiO2 shells and further modified via reduced glutathione (GSH), was successfully synthesized and applied for Pb(II) removal. Characterization results suggested that the prepared nanoadsorbents were in uniform size and provided numerous adsorption sites for Pb(II), nanoparticles could be convenient separated with the help of external magnet due to their superparamagnetism. Adsorption results showed that the prepared nanoadsorbents exhibited excellent adsorption capacity, even at a large range of Pb(II) concentrations and ionic strength scope. Kinetic of the Pb(II) adsorption was found to follow pseudo-second-order rate equation. Adsorption isotherm data was best fitted to Freundlich model (R2 = 0.9888–0.9959), and the maximal Pb(II) adsorption capacities were calculated as 298.87, 332.44 and 357.37 mg g−1, at 298, 303 and 308 K, respectively. Based on the efficient Pb(II) adsorption ability and reusability studies, Fe3O4 SiO2-GSH MNPs were confirmed to be a promising candidate for Pb(II) removal from industrial effluents.

Graphene quantum dots decorated with magnetic nanoparticles: Synthesis, electrodeposition, characterization and application as an electrochemical sensor towards determination of some amino acids at physiological pH

This study reports on the synthesis and characterization of a novel nano-composite, Fe3O4 magnetic nanoparticles/graphene quantum dots (Fe3O4 MNP-GQDs), for sensing of some amino acids. For the first time, as-synthesized GQDs and Fe3O4 MNPs-GQDs was electrodeposited on the glassy carbon electrode (GCE) by cyclic voltammetry (CV) regime in the potential range from −1.0 to 1.0V. Fe3O4 MNP-GQDs is engineered to specifically and effectively capture and enhancement the electrochemical signals of some amino acids at physiological pH due to the synergy among GQDs and magnetic nanoparticles. We have illustrated that the obtained Fe3O4 MNPs-GQDs exhibited a much higher electroactivity individual GQDs and Fe3O4 MNPs for the electrooxidation and detection of amino acid which was about 10 fold higher than for GQDs. Magnetic and specific properties of the Fe3O4 MNP-GQDs can be exploited to capture and pre-concentration the amino acids onto its surface, which are important for detection of multi-amino acids.

A facile green synthesis of spherical Fe3O4 magnetic nanoparticles and their effect on degradation of methylene blue in aqueous solution

We have been developed a facile and cost effective green synthesis of iron oxide magnetic nanoparticles (Fe3O4 MNPs) by using Ridge gourd peels (RG) extract as reducing and capping agent. The synthesized RG-FeMNPs are characterized by various physiochemical methods such as powder XRD, FT-IR, Raman, BET, FESEM, VSM and TEM methods. The results clearly demonstrated that the synthesized iron oxide (Fe3O4) nanoparticles are spherical in shape with an average size of 20–35nm. Besides, the nanoparticles exhibit very high specific surface area of 26.21m2/g. Further, the synthesized Fe3O4 nanoparticles exhibit ferromagnetic natures with higher saturation magnetization of 17.3 (emu/g). The catalytic properties of RG-FeMNPs for degradation of methylene blue (MB) dye in aqueous solution have been studied by UV–vis spectroscopy. The results show that the synthesized high surface area RG-FeMNPs has an excellent adsorption performance.

A colorimetric biosensor using Fe3O4 nanoparticles for highly sensitive and selective detection of tetracyclines

A novel colorimetric biosensor for the determination of tetracyclines (TCs) based on the Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) is presented in this paper. TCs are known to have a strong tendency to complex with metal ions such as Fe(II) and Fe(III) on the surface of Fe3O4 MNPs. Experiments results show that the complexation of Fe3O4 MNPs and TCs could lead to the accelerated catalysing H2O2-mediated oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by Fenton chemistry. The reaction starts with oxidation of Fe3O4 MNPs-TCs complex by dissolved oxygen to generate reactive oxygen species (ROS), primarily ·OH, leading to deepen the color of the solution. Analysis results can be seen with the naked eye and monitored by UV–vis spectra. Under the optimal conditions, the detection limits are 26nM for oxytetracycline (OTC), 45nM for tetracycline (TC) and 48nM for doxycycline (DOX). Moreover, this method has been applied for the determination of OTC content in drugs with satisfactory results. The proposed colorimetric biosensor is advantageous over other conventional methods in terms of convenient operation without any complicated chemical synthesis, modification, or tedious experimental procedures and its simple signal generation and detection by the naked eye. To the best of our knowledge, this is the first report on the enhancement effect of TCs on Fe3O4 MNPs-TMB-H2O2 reaction and its application in colorimetric TCs analysis. The designed colorimetric strategy may provide a promising alternative detection for TCs in clinical samples.

Magnetic nanoparticles grafted with amino-riched dendrimer as magnetic flocculant for efficient harvesting of oleaginous microalgae

Magnetic iron oxide (Fe3O4) nanoparticles (MNPs) was assigned to coat with amino-riched polyamidoamine (PAMAM) dendrimer (Fe3O4@PAMAM; Gn-dMNPs, n=0, 1, 2, 3) and employed in the magnetic harvesting of oleaginous Chlorella sp. HQ due to the highly positive branched structure. The coating process was realized by stepwise grafting which encompasses Michael addition and amidation reaction. Amino-micromolecular amino acids were used to modify Fe3O4 MNPs as control groups to investigate the difference of microalgal harvesting between modification with polymer and micromolecule firstly. The results showed that the coating of highly positive branched PAMAM dendrimer could dramatically promote the adsorption between algae cells and nanoparticles, leading to a large drop of nanoparticles dosage, compared with amino acid (AA)-modified Fe3O4 MNPs (Fe3O4@AA). The influence of polymer coating thickness which is an unclear factor on harvesting was explored initially, suggesting that the harvesting efficiency was positively correlated with the coating thickness of PAMAM dendrimer and reached over 95% within 2min when using 80mgL−1 G3-dMNPs at pH 8.0. Moreover, the harvesting efficiency rose dramatically when pH decreased from 10.0 to 4.0 for G0∼G2-dMNPs, while the high efficiency for G3-dMNPs could be maintained in a wide pH range for the amino-riched branched structure. It can be attributed to increased electrostatic attraction and bridging flocculation caused by abundant active sites of the highly positive branched network on Fe3O4 MNPs. It can be expected that this novel magnetic flocculant has the potential to be applied to harvesting of oleaginous microalgae due to its high efficiency and cycling stability.

Graphene quantum dot as an electrically conductive material toward low potential detection: a new platform for interface science

In the present study, the magnetic graphene quantum dot (Fe3O4 MNPs-GQDs) was synthesized successfully and characterized by using fourier transform infrared spectroscopy, transmission electron microscopy and atomic force microscopy (AFM). For the first time, as-synthesized GQDs and Fe3O4 MNPs-GQDs was electrodeposited on GCE by cyclic voltammetry (CV) in the potential range from −1.0 to 1.0 V and the prepared films were used for detection of Vitamin C at physiological pH. Herein, we explore the electrocatalytical activity of Fe3O4 MNPs-GQDs. We have illustrated that the as-obtained Fe3O4 MNPs-GQDs exhibited a much higher electroactivity individual GQDs and Fe3O4 MNPs for the electrooxidation and detection of Vitamin C which was about two fold higher than for GQDs. More importantly, a substantial (+0.21 V) decrease in the overvoltage of the Vitamin C oxidation reaction (compared to ordinary electrodes) was observed using Mag-GQDs-GCE. In general, Fast response time, excellent catalytic activity, lower overvoltage and ease of preparation are the advantages of the proposed nanosensor.

Synthesis, characterization and application of sulfonic acid supported on ferrite–silica superparamagnetic nanoparticles

In this study, the synthesis of sulfonic acid supported on ferrite–silica superparamagnetic nanoparticles (Fe3O4@SiO2@SO3H) as a nanocatalyst with large density of acidic groups is suggested. This nanocatalyst was prepared in three steps: preparation of colloidal iron oxide magnetic nanoparticles (Fe3O4 MNPs), coating of silica on Fe3O4 MNPs (Fe3O4@SiO2) and incorporation of sulfonic acid as a functional group on the surface of Fe3O4@SiO2 nanoparticles (Fe3O4@SiO2@SO3H). The properties of the prepared magnetic nanoparticles were characterized using transmission electron microscopy, infrared spectroscopy, vibrating sample magnetometry, X‐ray diffraction and thermogravimetric analysis. Finally, the applicability of the synthesized magnetic nanoparticles was tested as a heterogeneous solid acid nanocatalyst for one‐pot synthesis of diindolyloxindole derivatives in aqueous medium. Oxindole derivatives were produced by the coupling of indole and isatin compounds with good to high yields (60–98%). Copyright © 2016 John Wiley & Sons, Ltd.

Fe3O4 Magnetic Nanoparticles as Peroxidase Mimetics Used in Colorimetric Determination of 2,4-Dinitrotoluene

Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) were prepared by co-precipitation method, which possessed intrinsic peroxidase-like activity. It was found that the as-prepared Fe3O4 MNPs could not only catalyze the oxidation of peroxidase substrate, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate acid) (ABTS) by H2O2 to produce the colored product with maximum absorbance at 417 nm, but also catalyze the oxidation of 2,4-dinitrotoluene (DNT) by H2O2 and thus consume H2O2 in the reaction system. On the basis of the reaction mechanism described above, a novel colorimetric reaction system of Fe3O4 MNPs-ABTS-H2O2-DNT was established for the determination of trace amount of DNT. Some key influencing factors of the proposed Fe3O4 MNPs-ABTS-H2O2-DNT system were systematically discussed and optimized. Under the optimal conditions, the absorbance of the system at 417 nm displayed a good linear relationship with DNT concentration in the range from 5.0 × 10−7 M to 2.0 × 10−5 M with a detection limit of 1.5 × 10−7 M (S/N = 3). These results demonstrated that the constructed colorimetric method was simple, rapid and sensitive enough for the detection of DNT, which would have a great potential in the application of on-line monitoring of DNT in environmental water samples

A new functionalized magnetic nanocomposite of poly(methylacrylate) for the efficient removal of anionic dyes from aqueous media

A magnetic nano-adsorbent was synthesized via the radical polymerization of methyl acrylate on modified Fe3O4 MNPs, followed by amidation of the methyl ester groups using pentaethylenehexamine, to create active sites for adsorption of anionic dyes.