Properties Of Magnetite Nanoparticles Research Articles

Usnic Acid-Loaded Magnetite Nanoparticles-A Comparative Study between Synthesis Methods.

Since cancer is a continuously increasing concern for the general population, more efficient treatment alternatives ought to be developed. In this regard, a promising direction is represented by the use of magnetite nanoparticles (MNPs) to act both as a nanocarrier for the targeted release of antitumoral drugs and as hyperthermia agents. Thus, the present study focused on improving the control upon the outcome properties of MNPs by using two synthesis methods, namely the co-precipitation and microwave-assisted hydrothermal method, for the incorporation of usnic acid (UA), a natural lichen-derived metabolite with proven anticancer activity. The obtained UA-loaded MNPs were thoroughly characterized regarding their morpho-structural and physicochemical properties through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS) and zeta potential, scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). Results demonstrated the formation of magnetite as the unique mineralogical phase through both types of synthesis, with increased uniformity regarding the drug loading efficiency, size, stability, and magnetic properties obtained through the microwave-assisted hydrothermal method. Furthermore, the cytotoxicity of the nanostructures against the HEK 293T cell line was investigated through the XTT assay, which further proved their potential for anticancer treatment applications.

10-year stability of magnetite nanopowder prepared by the exploding wire method: is it a useful feature for environment safety and biomedical applications?

Aim. To analyze the structural, magnetic, and cytotoxic features of magnetite nanoparticles (MNPs) prepared by the exploding wire method and stored in a dark place at ambient temperature (65 ± 15% humidity, air pressure 760± 20 mm Hg., temperature 22 ± 4 °C) for 10 years.Materials and methods. The properties of MNPs were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), and vibrating-sample magnetometer (VSM). Viability of human blood mononuclear leukocytes was determined using 0.4% trypan blue staining after 24-hour culture with the nanopowder.Results. The calculated size of the particles remained almost unchanged after 10 years of storage. The XRD and SAED patterns showed that crystallinity was preserved for 10 years. The diameter of the crystalline component of MNPs (DXRD) was close to the particle size determined by TEM. It confirms high crystallinity of the tested nanoparticles. Saturation magnetization (MS) of the MNP powder after 10 years of storage was unexpectedly higher than that of the as-prepared MNP powder. Reduced remanent magnetization (MR / MS) was equal for both samples within the margin of error. No cytotoxic effect of MNPs in vitro was detected in the long-term study.Conclusion. No dramatic changes in the structural, magnetic, and cytotoxic features of MNPs were noted after 10 years of storage. It indicated 10-year stability of MNP powder that may be a useful feature for environment safety and biomedical applications.

Magnetite-Based Biosensors and Molecular Logic Gates: From Magnetite Synthesis to Application

In the last few decades, point-of-care (POC) sensors have become increasingly important in the detection of various targets for the early diagnostics and treatment of diseases. Diverse nanomaterials are used as building blocks for the development of smart biosensors and magnetite nanoparticles (MNPs) are among them. The intrinsic properties of MNPs, such as their large surface area, chemical stability, ease of functionalization, high saturation magnetization, and more, mean they have great potential for use in biosensors. Moreover, the unique characteristics of MNPs, such as their response to external magnetic fields, allow them to be easily manipulated (concentrated and redispersed) in fluidic media. As they are functionalized with biomolecules, MNPs bear high sensitivity and selectivity towards the detection of target biomolecules, which means they are advantageous in biosensor development and lead to a more sensitive, rapid, and accurate identification and quantification of target analytes. Due to the abovementioned properties of functionalized MNPs and their unique magnetic characteristics, they could be employed in the creation of new POC devices, molecular logic gates, and new biomolecular-based biocomputing interfaces, which would build on new ideas and principles. The current review outlines the synthesis, surface coverage, and functionalization of MNPs, as well as recent advancements in magnetite-based biosensors for POC diagnostics and some perspectives in molecular logic, and it also contains some of our own results regarding the topic, which include synthetic MNPs, their application for sample preparation, and the design of fluorescent-based molecular logic gates.

Green Synthesis of Unsaturated Fatty Acid Mediated Magnetite Nanoparticles and Their Structural and Magnetic Studies

The green, cost-effective and sustainable synthesis of nanomaterials has been a key concern of scientists and researchers. In this view, MNPs were prepared using a sapota plant leaf extract and the surface of the magnetite nanoparticles was engineered with unsaturated fatty acids. The first report on the effect of unsaturation on the size and magnetic properties of magnetite nanoparticles (MNPs), prepared by the co-precipitation method, has been studied by coating surfactants on MNPs based on their unsaturation from zero to three (lauric acid, oleic acid, linoleic acid, linolenic acid). The size effect and magnetic properties of MNPs coated with a surfactant have been studied in comparison with uncoated magnetite nanoparticles. After the surface modification of the magnetite particle, it is necessary to check whether the magnetic property has been restored or not. Therefore, the magnetic property was studied. The presence of a surfactant on the surface of MNPs was confirmed by Fourier-transform infrared spectroscopy (FTIR), which was later confirmed by scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The atomic structure was studied by X-ray diffraction (XRD) and the size of uncoated and surfactant-coated MNPs was determined by transmission electron microscopy (TEM) and the Scherrer equation by following XRD data. The magnetization property was analyzed by a vibrating sample magnetometer (VSM) at 10, 100 and 300 K and both bared and surfactant-coated MNPs exhibited a superparamagnetic nature at room temperature. The saturation magnetization (Ms) study shows that MNPs coated with a surfactant have a lower saturation magnetization value in comparison to uncoated NPs, confirming surface layering. Because the magnetic fluid has been stabilized in the aqueous medium, the double-layer model is expected to prevail.

Molarity Effects of Fe and NaOH on Synthesis and Characterisation of Magnetite (Fe3O4) Nanoparticles for Potential Application in Magnetic Hyperthermia Therapy

In this study, the effect of molarity on the structural, magnetic, and heat dissipation properties of magnetite nanoparticles (MNPs) was investigated to optimise the parameters for potential application in magnetic hyperthermia therapy (MHT). MHT works based on the principle of local temperature rise at the tumour site by magnetic iron oxide nanoparticles (MIONPs) with the application of an alternating magnetic field. MHT is a safe method for cancer treatment and has minimal or no side effects. Magnetite (Fe3O4) is the best material among MIONPs to be applied in local MHT due to its biocompatibility and high saturation magnetisation value. MNPs were prepared by co-precipitation at varying molarity. Structural characterisation was performed via X-ray powder diffraction (XRD) for crystalline structure analysis and field-emission scanning electron microscopy (FESEM) for morphology and particle size analysis. Measurement of the magnetic properties of the as-synthesised MNPs was carried out using a vibrating sample magnetometer (VSM). Power loss (P) was determined theoretically. The increase in molarity resulted in significant effects on the structural, magnetic, and heat dissipation properties of MNPs. The particle size and saturation magnetisation (Ms) decreased with the gradual addition of base but increased, together with crystallinity, with the gradual addition of iron source. M3 recorded the smallest crystalline size at 3.559 nm. The sample with the highest molarity (M4) displayed the highest heat generation capacity with a p value of up to 0.4056 W/g. High p values at the nano-scale are crucial, especially in local MHT, for effective heat generation, thus proving the importance of molarity as a vital parameter during MNP synthesis.

As (III) removal using superparamagnetic magnetite nanoparticles synthesized using Ulva prolifera − optimization, isotherm, kinetic and equilibrium studies

In this study, magnetite nanoparticles (MNPs) were synthesized using the seaweed – Ulva prolifera, an amply found marine source in the Western coastal regions of India. The surface and other properties of MNPs were characterized by many sophisticated methods. Spherical nanoclusters were observed in the FESEM image and iron and oxygen elements were seen in EDS results. XRD peaks were consistent with magnetite standards and MNPs had good crystallinity. FTIR portrayed the specific signals for MNPs and TGA profile ascertained the thermal stability. Magnetic saturation of 41.84 emu/g with negligible hysteresis loop substantiated the superparamagnetism. XPS pointed out the presence of Fe and O with oxidation states specific for MNPs, and the results were consistent with EDS. BET revealed a high specific surface area (144.98 m2/g) of MNPs with mesopores. The synthesized MNPs were used as nanoadsorbent for the removal of As (III) from aqueous solution. The central composite design was used for optimizing As (III) adsorption on MNPs. The optimum conditions were found out as 97.5% at pH: 9, rotation speed: 150 rpm, time: 90 min, and MNPs dosage: 1.15 g/L. The adsorption process fitted in a better way with the Langmuir isotherm and pseudo-second-order model. The highest adsorption capacity was 12.45 mg/g, which is substantially larger than the documenter reports. The spontaneous and endothermic nature of adsorption were ascertained from thermodynamic studies. The results suggested that the synthesized MNPs using the extract of U. prolifera could be alternative nanoadsorbents for eliminating toxic heavy metals from waste streams.

Changes of Lipid Peroxidation after Administration of Nanomodified Resuspending Solution into Donor Red Blood Cells

The problem of increasing the functional activity preservation of red blood cells is priority for the Blood Service and clinical transfusiology. Taking into account the previously discovered unique properties of magnetite nanoparticles, namely: nonspecific modulation of metabolic processes, strengthening of adaptive mechanisms of cellular organelles, acceleration of reparative processes at the level of membranes and macromolecules, for the first time an attempt was made to use the upgraded saline solution of sodium chloride (nanotechnologically upgraded solution - NUS) as a resuspending of erythrocyte-containing components (ECC). Objective: to improve the preservation of red blood cells containing donor blood components using NUS for resuspending. To achieve this goal, the first stage of the study examined the effect of a new resuspending solution (NUS) on lipoperoxidation, catalase activity, and red blood cell peroxidation resistance in donor blood components containing red blood cells. Object of Research: red blood cells from preservation blood of donors, which are intended for component transfusion therapy. As a result of the study, the advantages of using NUS were established, namely: a significant decrease in the levels of primary and secondary lipid peroxidation products in the first 15 days of observation, an increase in catalase activity and resistance of red blood cells to peroxidation in the first stages of the study, inhibition of the shear reaction with neutral lipid peroxidation in the late stages of observation.

Superparamagnetic Composite of Magnetite-CTAB as an Efficient Adsorbent for Methyl Orange

In this study, a superparamagnetic composite of magnetite-cetyltrimethylammonium bromide (CTAB) has been prepared by the coprecipitation method and then applied as a charge-selective adsorbent of anionic methyl orange (MO). The VSM (Vibrating Sample Magnetometer) measurement suggests the superparamagnetic property of MNPs (Magnetite Nano Particles) with a magnetic saturation of 49.2 emu g–1. The SEM image exhibits the significant difference in particle size from nanometers in uncoated magnetite to micrometers in magnetite-CTAB. Calculations with ImageJ software indicate that the diameter of the composite is in the range of 2–13 µm, with an average diameter of 6.56 µm, possibly consisting of hundreds to thousands of magnetite-CTAB micelles. The adsorption kinetics of MO over magnetite-CTAB follows the pseudo-second-order adsorption model of Ho and McKay with a rate constant (k2) of 3.54 × 103 g mol–1 min. The adsorption isotherm is well described by the Langmuir model with a Langmuir constant (KL) of 7.46 × 104 L mol and a maximum capacity (qm) of 27.9 mg g–1. The developed material is intriguing because it can be easily and quickly recovered using an external magnet after adsorption and selectively adsorbs anionic dyes.

Magnetic properties of iron oxide nanoparticles with a DMSA-modified surface

The magnetic properties of magnetite nanoparticles (Fe3O4 NPs) strongly depend on their chemical and physical parameters, which can be regulated by a controlled synthesis process. To improve the quality of the obtained nanoparticles, their surface is often modified with organic compounds (from the group of surfactants, sugars, proteins, or organic acid). In this study, we synthesized magnetite nanoparticles with a surface modified with the organic compound DMSA. Then, the nanocrystallites were characterized in terms of structure and morphology. To investigate the role of DMSA and to understand the adsorption mechanism, FTIR measurements were carried out. Using Mössbauer spectroscopy, we investigated temperature-induced changes in the magnetic properties of prepared samples. The spectra were recorded in a wide temperature range (from 4 K to 390 K) for two types of samples: powders and ferrofluids with various concentrations. In the case of powder samples, the superparamagnetic doublet appeared at room temperature. For magnetic suspensions, the spectra were more complicated. They consisted of superposition of asymmetrically broadened sextets and doublets, which was caused by the occurrence of long-range dipole-dipole interactions. These interactions affected the magnetic properties of the material and increased the blocking temperature. Additionally, the magnetic hysteresis and zero field cooling-field cooling (ZFC/FC) curves were measured with the use of a vibrating sample magnetometer.

Synthesis and properties of magnetite nanoparticles with peroxide‐containing polymer shell and nanocomposites based on them

AbstractMagnetite nanoparticles (Fe3O4 NPs) with peroxide‐containing polymer shell have been synthesized using the method of coprecipitation from the mixture solutions of Fe (II) and Fe (III) salts in the presence of peroxide‐containing copolymer (PCC). Polymer shell presence has been proved by elemental and complex thermal analysis. Synthesized Fe3O4 NPs possess superparamagnetic properties. Their specific saturation magnetization decreases gradually from 65 to 54 A·m2·kg−1 with increasing PCC concentration owing to the surface spin pinning effect caused by a polymer shell. The average sizes of Fe3O4 NPs estimated from the data of XRD analysis and magnetic measurements are in the range of 9–12 nm. The NP sizes determined by the DLS method lie in the range of 150–270 nm; this result is significantly larger than the sizes estimated by the two aforementioned methods evidencing a tendency for Fe3O4 NPs toward self‐association. Cross‐linked composite films based on polyvinyl alcohol have been obtained via radical curing initiated by the PCC shell of nanoparticles. The resulting composite films are magnetically sensitive films with rather high physico‐mechanical properties (tensile strength reaches 48–67 MPa and relative elongation – 4%–21% depending on cross‐linking degree), a priori non‐toxic and biocompatible, which makes them promising materials for various applications.

Photopolymerization-Based Synthesis of Uniform Magnetic Hydrogels and Colorimetric Glucose Detection.

Magnetic hydrogels have been commonly used in biomedical applications. As magnetite nanoparticles (MNPs) exhibit peroxidase enzyme-like activity, magnetic hydrogels have been actively used as signal transducers for biomedical assays. Droplet microfluidics, which uses photoinitiated polymerization, is a preferred method for the synthesis of magnetic hydrogels. However, light absorption by MNPs makes it difficult to obtain fully polymerized and homogeneous magnetic hydrogels through photoinitiated polymerization. Several methods have been reported to address this issue, but few studies have focused on investigating the light absorption properties of photoinitiators. In this study, we developed a simple method for the synthesis of poly(ethylene glycol) (PEG)-based uniform magnetic hydrogels that exploits the high ultraviolet absorption of a photoinitiator. Additionally, we investigated this effect on shape deformation and structural uniformity of the synthesized magnetic hydrogels. Two different photoinitiators, Darocur 1173 and lithium phenyl (2,4,6–trimethylbenzoyl) phosphinate (LAP), with significantly different UV absorption properties were evaluated based on the synthesis of magnetic hydrogels. The magnetic characteristics of the PEG-stabilized MNPs in hydrogels were investigated with a vibrating sample magnetometer. Finally, the colorimetric detection of hydrogen peroxide and glucose was conducted based on the enzyme-like property of MNPs and repeated several times to observe the catalytic activity of the magnetic hydrogels.

Gold nanotriangles with magnetite satellites

This work describes the synthesis of hybrid particles of gold nanotriangles (AuNTs) with magnetite nanoparticles (MNPs) by using 1-mercaptopropyl-3-trimethoxysilan (MPTMS) and L-cysteine as linker molecules. Due to the combination of superparamagnetic properties of MNPs with optical properties of the AuNTs, nanoplatelet-satellite hybrid nanostructures with combined features become available. By using MPTMS with silan groups as linker molecule a magnetic “cloud” with embedded AuNTs can be separated. In presence of L-cysteine as linker molecule at pH > pHiso a more unordered aggregate structure of MNPs is obtained due to the dimerization of the L-cysteine. At pH < pHiso water soluble positively charged AuNTs with satellite MNPs can be synthesized. The time-dependent loading with MNP satellites under release of the extinction and magnetization offer a hybrid material, which is of special relevance for biomedical applications and plasmonic catalysis.

Importance of Surfactant Quantity and Quality on Growth Regime of Iron Oxide Nanoparticles.

This study shows the influence of selected nonstandard surfactants on the growth and properties of magnetite nanoparticles. Particles were obtained using thermally decomposed iron (III) acetylacetonate in an organic environment. For synthesis, three different concentrations (4, 8, and 16 mmol) of tested surfactants were used. Five types of each long-chain carboxylic acid and amines were selected for stabilization of nanoparticles. Nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, and infrared spectroscopy. Magnetic properties of the nanoparticles were tested by conventional room temperature Mössbauer spectroscopy with and without external magnetic field. TEM images clearly showed that application of tertiary amines causes the nanoparticles to form nanoflowers, in contrast to other compounds, which do not show such growth. Influence of surfactant amount on growth regime depends on the nature of the substances. Mössbauer spectroscopy confirms differences in magnetic core composition as a result of the surfactant amount present in synthetic procedure.

Magnetically directed antioxidant and antimicrobial agent: synthesis and surface functionalization of magnetite with quercetin.

Oxidative stress can be reduced substantially using nanoantioxidant materials by tuning its surface morphological features up to a greater extent. The physiochemical, biological and optical properties of the nanoantioxidants can be altered by controlling their size and shape. In view of that, an appropriate synthesis technique should be adopted with optimization of the process variables. Properties of magnetite nanoparticles (IONP) can be tailored to upgrade the performance of biomedicine. Present research deals with the functionalization IONP using a hydrophobic agent of quercetin (Q). The application of quercetin will control its size using both the functionalization method including in-situ and post-synthesis technique. In in-situ techniques, the functionalized magnetite nanoparticles (IONP@Q) have average particles size 6 nm which are smaller than the magnetite (IONP) without functionalization. After post functionalization technique, the average particle size of magnetite IONP@Q2 determined was 11 nm. The nanoparticles also showed high saturation magnetization of about 51–59 emu/g. Before starting the experimental lab work, Prediction Activity Spectra of Substances (PASS) software was used to have a preliminary idea about the biological activities of Q. The antioxidant activity was carried out using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The antibacterial studies were carried out using well diffusion method. The results obtained were well supported by the simulated results. Furthermore, the values of the half maximal inhibitory concentration (IC50) of the DPPH antioxidant assay were decreased using the functionalized one and it exhibited a 2–3 fold decreasing tendency than the unfunctionalized IONP. This exhibited that the functionalization process can easily enhance the free radical scavenging properties of IONPs up to three times. MIC values confirms that functionalized IONP have excellent antibacterial properties against the strains used (Staphylococcus aureus, Bacillus subtilis and Escherichia coli) and fungal strains (Aspergillus niger, Candida albicans, Trichoderma sp. and Saccharomyces cerevisiae). The findings of this research showed that the synthesized nanocomposite has combinatorial properties (magnetic, antioxidant and antimicrobial) which can be considered as a promising candidate for biomedical applications. It can be successfully used for the development of biomedicines which can be subsequently applied as antioxidant, anti-inflammatory, antimicrobial and anticancer agents.

Structure, Optical, and Magnetic Properties of Magnetite Nanoparticles Doped with Zinc and Lanthanum and Prepared in Oxygen and Nitrogen Atmosphere

Structure, Optical, and Magnetic Properties of Magnetite Nanoparticles Doped with Zinc and Lanthanum and Prepared in Oxygen and Nitrogen Atmosphere

ChemInform Abstract: Bioinspired Magnetite Synthesis via Solid Precursor Phases

AbstractReview: 106 refs.

Fabrication and study of properties of magnetite nanoparticles in hybrid micelles of polystyrene-block-polyethylene oxide and sodium dodecyl sulfate

Magnetite nanoparticles have been formed for the first time in hybrid micelles of polystyrene-block-polyethylene oxide and sodium dodecyl sulfate in water by ultrasonic treatment at room temperature. An analysis by small-angle X-ray scattering and transmission electron microscopy (TEM) showed that magnetite nanoparticles in hybrid micelles of block copolymer and sodium dodecyl sulfate are polydesperse (have sizes from 0.5 to 20 nm). The specific magnetization of solid samples has been measured.

Properties of magnetite nanoparticles produced by magnetotactic bacteria

The magnetic nanoparticles (magnetite) were prepared through the fermentation of the Magnetospirillum strain WM-1 newly isolated by our group. The samples were characterized by TEM, SAED, XRD, rock magnetic analysis, and Mossbauer spectroscopy. TEM and SAED measurements showed that the magnetosomes formed by strain WM-1 were single crystallites of high perfection with a cubic spinel structure of magnetite. X-ray measurements also fitted very well with standard Fe3O4 reflections with an inverse spinel structure of the magnetite core. The size of crystal as calculated by the Debye-Scherrer’s equation was approximately 55 nm. Rock magnetic analysis showed WM-1 synthesized single-domain magnetite magnetosomes, which were arranged in the form of linear chain. The high delta ratio ((δFC / δZFC = 4) supported the criteria of Moskowitz test that there were intact magnetosomes chains in cells. The Verwey transition occurred at 105 K that closed to stoochiometric magnetite in composition. These observations provided useful insights into the biomineralization of magnetosomes and properties of M. WM-1 and potential application of biogenic magnetite in biomaterials and biomagnetism.

Structural, Compositional, and Biological Characterization of Fe3O4 Nanoparticles Synthesized by Hydrothermal Method

In this research, magnetite nanoparticles (MNPs) have been prepared at 200°C for 2 h by hydrothermal method in presence of 3-mercaptopropionic acid (3-MPA) as a capping agent. Morphological and structural studies carried out by scanning electron microscope (SEM), that results show nanoparticles have been constructed in cubic shape with medium size about 20–30 nm, can produce clusters in 50–200 nm. X-ray diffraction results show that MNPs are in cubic crystal phase. Investigation of thermochemical properties and changing state of Fe2O3 in higher temperature, carried out with analysis of STA (DTA/TGA) that shows MNPs have changed the phase in 280°C and converted to hematite (α-Fe2O3) with rhombohedral crystal phase. Investigation of anticancer properties of nanoparticles show that after 72 h excellent anti-tumor activity against two kinds of cancer cells that are LNCAP (human prostate carcinoma) cells and HeLa (human cervix carcinoma) cells. The results are completely new and provide new views for using of the mentioned compounds in chemotherapy. Antibacterial properties of MNPs also have been studied and good results obtained.

Synthesis and Properties of Magnetite Nanoparticles Coated with Poly(ethylene glycol) and Poly(ethylene imine)

Water-soluble magnetite nanoparticles were synthesized by thermal decomposition of iron(III) acetylacetonate in poly(ethylene glycol) in the presence of poly(ethylene imine). The amount of poly(ethylene imine), the reaction temperature and time are found to have significant effects on the shape evolution and size distribution of the magnetite nanoparticles. The prepared magnetite nanoparticles show superparamagnetic behavior at 300 K. Coated with poly(ethylene glycol) and poly(ethylene imine) the magnetite nanoparticles are positively charged and highly soluble in deionized water with small hydrodynamic size, and show longer time dispersion in water except the magnetite nanoparticles prepared with insufficient amount of poly(ethylene imine).