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The absence of adequate methods for hydrogen storage has prevented the implementation of hydrogen as a major source of energy. Graphene-based materials have been considered for use as solid hydrogen storage, because of graphene's high specific surface area. However, these materials alone do not meet the hydrogen storage standard of 6.5 wt.% set by the United States Department of Energy (DOE). They can, however, be easily modified through either decoration or doping to alter their chemical properties and increase their hydrogen storage capacity. This review is a compilation of various published reports on this topic and summarizes results from theoretical and experimental studies that explore the hydrogen storage properties of metal-modified graphene materials. The efficacy of alkali, alkaline earth metal, and transition metal decoration is examined. In addition, metal doping to further increase storage capacity is considered. Methods for hydrogen storage capacity measurements are later explained and the properties of an effective hydrogen storage material are summarized. [ABSTRACT FROM AUTHOR]

The electrocatalytic recycling of waste nitrate (NO3RR) is a promising decentralized route for green ammonia synthesis. Nonetheless, it suffers from the competing hydrogen evolution reaction and the insufficient proton supply in high pH conditions. Herein, iron oxide nanoparticles anchored on ZnO is introduced as a strategy to enhance the water dissociation ability and proton transfer rate, advancing NH4+ production from alkaline NO3RR. Supported by a set of ex situ and in situ characterization, the findings reveal the reduction of iron oxides, along with improvements in charge transfer properties and proton generation from H2O. Theoretical calculations show that iron oxides reduce the kinetic barrier of the rate‐limiting step (*NO2‐to‐*NO2H) and result in a thermodynamically favorable process to hydrogenation steps, which in turn reduce the overall energy barrier of alkaline NO3RR. Optimal catalytic activity is realized with a Fe loading of 0.5 wt.%, delivering a Faradaic efficiency of ≈83% for ammonium with a NH4+ yield rate of 31 nmol s−1 cm−2 at −0.7 V versus RHE. The results pave the way for the utilization of bi‐metal interaction to tune the reaction pathway for achieving sustainable ammonium synthesis in alkaline, contributing to ongoing efforts to achieve a sustainable nitrogen cycle via N‐based electrochemistry. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance (AMR) is growing into a major public health crisis worldwide. The reducing alternatives to conventional agents starve for novel antimicrobial agents. Due to their unique magnetic properties and excellent biocompatibility, iron oxide nanoparticles (IONPs) are the most preferable nanomaterials in biomedicine, including antibacterial therapy, primarily through reactive oxygen species (ROS) production. IONP characteristics, including their size, shape, surface charge, and superparamagnetism, influence their biodistribution and antibacterial activity. External magnetic fields, foreign metal doping, and surface, size, and shape modification improve the antibacterial effect of IONPs. Despite a few disadvantages, IONPs are expected to be promising antibacterial agents of a new generation. [ABSTRACT FROM AUTHOR]

Photothermal therapy (PTT) can overcome cancer treatment resistance by enhancing the cell membrane permeability, facilitating drug accumulation, and promoting drug release within the tumor tissue. Iron oxide nanoparticles (IONPs) have emerged as effective agents for PTT due to their unique properties and biocompatibility. Approved for the treatment of anemia, as MRI contrast agents, and as magnetic hyperthermia mediators, IONPs also offer excellent light-to-heat conversion and can be manipulated using external magnetic fields for targeted accumulation in specific tissue. Optimizing parameters such as the laser wavelength, power density, shape, size, iron oxidation state, functionalization, and concentration is crucial for IONPs' effectiveness. In addition to PTT, IONPs enhance other cancer treatment modalities. They improve tumor oxygenation, enhancing the efficacy of radiotherapy and photodynamic therapy. IONPs can also trigger ferroptosis, a programmed cell death pathway mediated by iron-dependent lipid peroxidation. Their magneto-mechanical effect allows them to exert a mechanical force on cancer cells to destroy tumors, minimizing the damage to healthy tissue. This review outlines strategies for the management of the photothermal performance and PTT efficiency with iron oxide nanoparticles, as well as synergies with other cancer therapies. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles were synthesized by co-precipitation using three different iron salt stoichiometric mole ratios. Powder X-ray diffraction patterns revealed the inverse cubic spinel structure of magnetite iron oxide. Transmission electron microscopic images showed Fe3O4 nanoparticles with different shapes and average particle sizes of 5.48 nm for Fe3O4-1:2, 6.02 nm for Fe3O4-1.5:2, and 6.98 nm for Fe3O4-2:3 with an energy bandgap of 3.27 to 3.53 eV. The as-prepared Fe3O4 nanoparticles were used as photocatalysts to degrade brilliant green (BG), rhodamine B (RhB), indigo carmine (IC), and methyl red (MR) under visible light irradiation. The photocatalytic degradation efficiency of 80.4% was obtained from Fe3O4-1:2 for brilliant green, 61.5% from Fe3O4-1.5:2 for rhodamine B, and 77.9% and 73.9% from Fe3O4-2:3 for both indigo carmine and methyl red. This indicates that Fe3O4-2:3 is more efficient in the degradation of more than one dye. This study shows that brilliant green degrades most effectively at pH 9, rhodamine B degrades best at pH 6.5, and indigo carmine and methyl red degrade most efficiently at pH 3. Recyclability experiments showed that the Fe3O4 photocatalysts can be recycled four times and are photostable. [ABSTRACT FROM AUTHOR]

Rapid advancements in nanotechnology have expanded its applications and synergistic impact on modern nanosystems. The comprehensive assessment of nanomaterials' safety for human exposure has become crucial and heightened. In addition to the characterization of cell proliferation and apoptosis, probing the implication of autophagy is vital for understanding the ramification of nanomaterials. Hence, HEK-293 kidney cells were employed to understand the changes in induction and perturbation of autophagy in cells by iron oxide (Fe3O4) and silica (SiO2) nanoparticles. Interestingly, Fe3O4 worked as a potent modulator of the autophagy process through its catalytic performance, which can develop better than that of SiO2 nanoparticles mechanism, stressing their therapeutic implication in the understanding of cell behaviors. The quantification of reactive oxygen species (ROS) was measured along with the process of autophagy during cell growth. This modulated autophagy will help in cell fate determination in complementary therapy for disease treatment, provide a clinical strategy for future study. [ABSTRACT FROM AUTHOR]

Cancer is one of the leading causes of global mortality, and its incidence is increasing annually. Neutron capture therapy (NCT) is a unique anticancer modality capable of selectively eliminating tumor cells within normal tissues. The development of accelerator-based, clinically mountable neutron sources has stimulated a worldwide search for new, more effective compounds for NCT. We synthesized magnetic iron oxide nanoparticles (NPs) that concurrently incorporate boron and gadolinium, potentially enhancing the effectiveness of NCT. These magnetic nanoparticles underwent sequential modifications through silane polycondensation and allylamine graft polymerization, enabling the creation of functional amino groups on their surface. Characterization was performed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), dynamic light scattering (DLS), thermal gravimetric analysis (TGA), and transmission electron microscopy (TEM). ICP-AES measurements indicated that boron (B) content in the NPs reached 3.56 ppm/mg, while gadolinium (Gd) averaged 0.26 ppm/mg. Gadolinium desorption was observed within 4 h, with a peak rate of 61.74%. The biocompatibility of the NPs was confirmed through their relatively low cytotoxicity and sufficient cellular tolerability. Using NPs at non-toxic concentrations, we obtained B accumulation of up to 5.724 × 1010 atoms per cell, sufficient for successful NCT. Although limited by its content in the NP composition, the Gd amount may also contribute to NCT along with its diagnostic properties. Further development of the NPs is ongoing, focusing on increasing the boron and gadolinium content and creating active tumor targeting. [ABSTRACT FROM AUTHOR]

This work presents the green synthesis of iron oxide nanoparticles (IONPs) using Baccharis salicifolia extract and their incorporation in mesoporous silica MCM-41, obtaining an MCM-41@IONP composite. The MCM-41@IONP composite was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption and desorption, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The use of the natural reducing agent Baccharis salicifolia resulted in nanoparticles with an average size of 31 nm. Furthermore, we showcase the application of the MCM-41@IONP nanocomposite in a metal–insulator–semiconductor (MIS) diode, which was fabricated at room temperature. The current–voltage and capacitance–voltage curves of the MIS diode were carefully measured and subjected to detailed analysis. The results demonstrate the potential utility of MCM-41@IONP nanocomposite-based MIS diodes, suggesting their applicability in the design of biosensors or as discrete components in electronic devices. [ABSTRACT FROM AUTHOR]

The study of iron nanoparticles is one of the most researched areas in recent times due to the potential applications they have and because the study of iron by XPS is one of the most debated elements. In this work, we provide investigation data of iron oxide nanoparticles produced using the laser ablation technique, which were characterized using x-ray photoelectron spectroscopy. Survey spectra, C 1s, O 1s, and Fe 2p core levels spectra were acquired. Results showed the presence of Fe+3 and Fe+2 elements that constitute hematite and magnetite with differences in their concentrations depending on the fitting method. In addition, the presence of adventitious carbon and carbon from impurities was detected. [ABSTRACT FROM AUTHOR]

In this study, Fe3O4/Ag magnetite-silver (MSx) nanocomposites were investigated as catalysts for advanced oxidation processes by coupling the plasmonic effect of silver nanoparticles and the ferromagnetism of iron oxide species. A surfactant-free co-precipitation synthesis method yielded pure Fe3O4 magnetite and four types of MSx nanocomposites. Their characterisation included structural, compositional, morphological and optical analyses, revealing Fe3O4 magnetite and Ag silver phases with particle sizes ranging from 15 to 40 nm, increasing with the silver content. The heterostructures with silver reduced magnetite particle aggregation, as confirmed by dynamic light scattering. The UV–Vis spectra showed that the Fe:Ag ratio strongly influenced the absorbance, with a strong absorption band around 400 nm due to the silver phase. The oxidation kinetics of organic pollutants, monitored by in situ luminescence measurements using rhodamine B as a model system, demonstrated the higher performance of the developed catalysts with increasing Ag content. The specific surface area measurements highlighted the importance of active sites in the synergistic catalytic activity of Fe3O4/Ag nanocomposites in the photo-Fenton reaction. Finally, the straightforward fabrication of diverse Fe3O4/Ag heterostructures combining magnetism and plasmonic effects opens up promising possibilities for heterogeneous catalysis and environmental remediation. [ABSTRACT FROM AUTHOR]

Ferrofluids based on magnetic iron oxide nanoparticles (IONPs) have been widely studied as multipurpose agents in various medical applications including magnetic hyperthermia, targeted drug delivery and magnetic resonance imaging (MRI). To increase their stability and compatibility with the living cells and thus improve their suitability for these purposes, the IONPs are often functionalized with different organic or inorganic molecules. In this work we report on the preparation of polyvinilpyrrolidone (PVP) functionalized IONPs through a simple co-precipitation method and investigated their suitability for magnetic hyperthermia and as a MRI contrast agent. Spherical PVP-coated IONPs, with an average particle size of ≈ 15 nm, showed superparamagnetic behavior and high saturation magnetization Ms = 80.7 emug−1, at room temperature. The specific absorption rate (SAR), a measure of the heating ability, ranged from 17 W/g to 721 W/g (evaluated for various combinations of AC magnetic field amplitudes and frequencies), while the intrinsic loss power (ILP) was in the range from 0.53 nHm2 kg−1 to 2.34 nHm2 kg−1. In addition to relatively good heating ability, high T2 relaxivity, r2 = 126 mM−1 s−1 and high r2/r1 ratio demonstrated that the preparation procedure used here can yield nanoparticles suitable for MRI guided localized magnetic hyperthermia. [ABSTRACT FROM AUTHOR]

A commercial activated carbon (AC) was modified through iron oxide incorporation to obtain microwave absorbers (MWAs) for microwave-assisted pyrolysis. The influence of iron oxide content (5 and 20 wt% Fe3O4) and the modification methods were tested as follows: (1) in situ co-precipitation + washing step with Milli-Q; (2) in situ co-precipitation + washing step with Milli-Q/ethanol; and (3) physical iron oxide blending. The resulting MWAs were evaluated on the microwave-assisted pyrolysis of hardwood in a Milestone Flexiwave microwave reactor. The biochar yield varied from 24 wt% to 89 wt% and was influenced by the modification method rather than the iron oxide addition. The MWAs with physically blended iron oxide resulted in biochar yields comparable to conventional biochar (450 °C). Furthermore, the addition of iron oxide-activated carbon composites during the microwave-assisted pyrolysis caused a significant decrease in the biochar's 16 EPA polycyclic aromatic hydrocarbons, mainly by reducing the amount of pyrene in the biochar. [ABSTRACT FROM AUTHOR]

The synthesis of novel catalysts for the oxygen reduction reaction, by means of a fast one-pot microwave-assisted procedure, is reported herein and deeply explained. In particular, the important role of doping atoms, like sulfur and nitrogen, in Fe2O3-reduced graphene oxide nanocomposites is described to address the modification of catalytic performance. The presence of dopants is confirmed by X-ray Photoelectron Spectroscopy analysis, while the integration of iron oxide nanoparticles, by means of decoration of the graphene structure, is corroborated by electron microscopy, which also confirms that there is no damage to the graphene sheets induced by the synthesis procedure. The electrochemical characterizations put in evidence the synergistic catalysis effects of dopant atoms with Fe2O3 and, in particular, the importance of sulfur introduction into the graphene lattice. Catalytic performance of as-prepared materials toward oxygen reduction shows values close to the Pt/C reference material, commonly used for fuel cell and metal–air battery applications. [ABSTRACT FROM AUTHOR]

The work reported here deals with fabricating iron oxide nanoparticles incorporated polyvinyl alcohol nanocomposite films via the solution‐casting green route, characterized using various characterization techniques. X‐ray diffraction analysis shows interaction of nanoparticles with the polyvinyl alcohol matrix, scanning electron microscopy shows surface morphology of crack‐free films, energy dispersive spectroscopy indicates elemental purity, tensiometer analysis shows changing behavior of hydrophilic to hydrophobic, thermogravimetric analysis shows improved thermal stability, ultraviolet‐visible spectroscopy shows tunable optical properties, and frequency response analysis shows improved electrical properties. A small incorporation (1 wt. %) of iron oxide nanoparticles has induced significant alternations in structural, wetting, thermal, optical, and electrical properties of the polyvinyl alcohol‐based nanocomposite films. Results showed notable changes in the structural phases, water contact angle (39.5° to 97.7°), optical absorption edge (5.12 eV to 4.84 eV), indirect band gap (4.99 eV to 4.68 eV), direct bandgap (5.41 eV to 5.21 eV), and band tail (0.57 eV to 0.89 eV) from native polyvinyl alcohol to polyvinyl alcohol/iron oxide nanocomposite films. Enhancements were observed in refractive indices, optical conductivity, optical dielectric loss, thermal stability, dielectric constant, and dielectric loss on incorporating iron oxide nanoparticles into the polyvinyl alcohol matrix. The fabricated nanocomposite films might be a potential material for optoelectronic and microelectronics applications. [ABSTRACT FROM AUTHOR]

Magnetic iron oxide nanoparticles immobilized on microcrystalline cellulose (MCC) are studied for the adsorption of Pb(II) ions from an aqueous solution. Composites of iron oxide and MCC were synthesized with a 5%–20% loading of iron (w/w%). The effect of pH, concentration, and contact time was studied. The adsorption isotherms were fitted to nonlinear Langmuir, Freundlich, and Dubinin–Radushkevich (D‐R) isotherms, and kinetics were studied for pseudo‐first and second‐order kinetic fit models. Adsorption of Pb(II) ions increased with increasing pH value up to 5. Maximum adsorption of Pb(II) was observed up to 299.91 mg−1 in D‐R equilibrium for onto MCC‐Iron oxide composite for composite with iron loading of 20% at pH 5. [ABSTRACT FROM AUTHOR]

Root-to-shoot translocation of nanoparticles (NPs) is a matter of interest due to their possible unprecedented effects on biota. Properties of NPs, such as structure, surface charge or coating, and size, determine their uptake by cells. This study investigates the size effect of iron oxide (Fe3O4) NPs on plant uptake, translocation, and physiology. For this purpose, Fe3O4 NPs having about 10 and 100 nm in average sizes (namely NP10 and NP100) were hydroponically subjected to barley (Hordeum vulgare L.) in different doses (50, 100, and 200 mg/L) at germination (5 days) and seedling (3 weeks) stages. Results revealed that particle size does not significantly influence the seedlings' growth but improves germination. The iron content in root and leaf tissues gradually increased with increasing NP10 and NP100 concentrations, revealing their root-to-shoot translocation. This result was confirmed by vibrating sample magnetometry analysis, where the magnetic signals increased with increasing NP doses. The translocation of NPs enhanced chlorophyll and carotenoid contents, suggesting their contribution to plant pigmentation. On the other hand, catalase activity and H2O2 production were higher in NP10-treated roots compared to NP100-treated ones. Besides, confocal microscopy revealed that NP10 leads to cell membrane damages. These findings showed that Fe3O4 NPs were efficiently taken up by the roots and transported to the leaves regardless of the size factor. However, small-sized Fe3O4 NPs may be more reactive due to their size properties and may cause cell stress and membrane damage. This study may help us better understand the size effect of NPs in nanoparticle-plant interaction. [ABSTRACT FROM AUTHOR]

This study comprehensively investigated the effect of iron-oxide nanoparticles (NPs) on weathering durability and thermal resistance of wood-plastic composites (WPCs). The hydrophobic nature of NPs improved the dimensional stability of WPCs. The small size of NPs deposits the voids in the matrix, which helps to increase the mechanical properties, even after weathering test. The decrease of modulus of rupture (MOR) reached up to 16% for control samples, while it was 2% for IO40-1. Despite the intensive weathering conditions, NPs cover the surface of materials like a UV shield, improving WPCs' UV resistance. Moreover, the increase in the wood and NPs content limited the UV degradation, which resulted in lower color changes. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) analysis also proved that there were nearly no changes in the characteristic bands of polymer (2916 and 2846 cm−1) and wood (1512 cm−1). The microscopic investigation, however, revealed the deterioration on the surface of WPCs after weathering exposure. Even though UV degradation is inevitable, iron oxide NPs significantly preserved the WPCs surface. However, there were also crack formations, which were also inhibited. On the other hand, NPs decelerated the thermal degradation by acting as a heat barrier. Thermogravimetric analysis (TGA) analysis revealed an increase in the degradation temperature. Limit oxygen index (LOI) values also increased up to 27.6%, which demonstrated an improvement against flammability. [ABSTRACT FROM AUTHOR]

Here, amino acids-functionalized iron oxide nanoparticles were synthesized by utilizing the co-precipitation methodology. The synthesized nanoparticles (including alanine, valine, and phenylalanine-functionalized nanoparticles) were characterized by utilizing several analytical techniques. Acquired outcomes validated the successful formation of amino acid-functionalized iron oxide nanoparticles. The X-ray diffraction and scanning electron microscopy indicated that phenylalanine-based iron oxide nanoparticles exhibited high crystallinity and better fabrication, respectively, in comparison with other amino acids. This was attributed to the development of high hydrophobic interactions of the phenylalanine with the iron oxide nanoparticles. The photocatalytic efficacy of the iron oxide nanoparticles against the methylene blue was investigated by implementing two different optimization strategies (i.e., traditional one-variable-at-a-time kinetics and advanced response surface methodology). The experiment performed by using phenylalanine-functionalized iron oxide nanoparticles as a photocatalyst under optimized conditions revealed that the highest efficacy of 92.91 and 97.12% was obtained by using the one-variable-at-a-time and response surface methodology approaches, respectively, indicating that the latter approach is more effective for the optimization of the understudy reactions. In terms of comparative effectiveness of the reaction parameters, the photocatalyst dose was found to be the most effective emphasizing that special emphasis should be given to this parameter when dealing with the optimization of this reaction on an industrial scale. The total organic carbon analysis further revealed that the mineralization of 90.216% was achieved under optimized reaction conditions. The prepared iron oxide nanoparticles exhibited strong photocatalytic potential for the understudy chemical reaction. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles have been attracted extensively due to their supermagnetic properties, preferred in biomedicine because of their biocompatibility and potential nontoxicity to human beings. Synthesis of iron nanoparticles (FeNPs) was prepared with the help of ferric chloride and ferrous sulphate by using the coprecipitation method. The variation and combination of ferric and ferrous concentrations affect the physical and magnetic properties of iron oxide nanoparticles. The effect of 0.1 M ferric and ferrous concentration on iron oxide nanoparticles was studied separately and in combination. The obtained nanoparticles were characterized by Particle size, zeta potential, Ultraviolet (UV-visible), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Thermal gravimetric analysis (TGA), and Vibratingsample magnetometer (VSM) techniques. Particle size was below 200 nm and zeta potential was within the limit for all the batches. UV visible spectra at 224 nm, and FTIR exhibit two peaks at 510 and 594 cm-1, indicating iron oxide NPs and XRD confirmed the crystalline nature of Fe. SEM showed a spherical shape for all batches. The use of a combination of ferric and ferrous is more effective than its individual use. TGA and VSM studies confirmed its magnetic properties. [ABSTRACT FROM AUTHOR]

The work provides a study of the effects of an external uniform magnetic field on the underwater pulsed discharge burning process. The presence of a magnetic field affects the waveforms of current and voltage, resulting in a decrease in amplitude values and frequency of discharge pulses. The presence of an external magnetic field was found to affect processes of the synthesis of iron oxide powders. Different polymorphic modifications of Fe2O3 were obtained depending on the orientation of the magnetic field. The formation of larger iron oxide nanoparticles is facilitated by the magnetic field. The release of desublimation energy, accompanied by heating, encourages the increasing the degree of crystallinity of samples in the presence of a magnetic field. Shown, that the presence of an external magnetic field has significant effects on the underwater pulsed discharge process, altering the electrical properties of the discharge and influencing the synthesis of oxide nanoparticles. [ABSTRACT FROM AUTHOR]

Nanoparticles have been shown to inhibit major life cycle stages of ticks, indicative of the promising application of nanomaterials against hard ticks. The study thus probed into one of the alternative options to curtail Hyalomma by employing nanocomposites consisting of pyrethroids (cypermethrin and deltamethrin) coated nanoparticles of iron oxides and iron sulfides keeping alongside the evaluation of their toxicity through plant and mammalian cell lines. The nanoparticles used in this study were roughly spherical in morphology and exhibited various size dimensions upon characterization using SEM, EDX, and FTIR. The application of nanomaterials on female ovipositioning tick showed a decline up to 15% (females ovipositioned) in deltamethrin-coated FeO NPs, whereas this decline was up to 18% in Cyp-FeS NPs and up to 5% in Cyp-FeO NPs. Similarly, the larval hatching was also impacted, leading to a hatching percentage of 5% and only 1% by application of Cyp-FeS NPs and Cyp-FeO NPs, respectively. Similarly, the larval groups had LC90 of 4.1 and 4.73 mg/L for the Cyp-FeO NPs and Cyp-FeS NPs groups. The delta-FeO NPs and delta-FeS NPs demonstrated a promising effect against adult ticks, showing LC50= 3.5 mg/L, LC90= 6.7 mg/L and LC50= 3.8 mg/L, LC90= 7.9 mg/L, respectively. MTT assay revealed that the pyrethroids coupled with iron oxide nanoparticles showed the least cytotoxicity even at the highest concentration (10–1 µL) among other nanomaterials. The study thus concluded a safer spectrum of non-target effects of pyrethroids-coated nanomaterials in addition to their significant anti-tick activity. [ABSTRACT FROM AUTHOR]

[Display omitted] Macrophages are known to depict two major phenotypes: classically activated macrophages (M1), associated with high production of pro-inflammatory cytokines, and alternatively activated macrophages (M2), which present an anti-inflammatory function. A precise control over M1-M2 polarization is a promising strategy in therapeutics to modulate both tissue regeneration and tumor progression processes. However, this is not a simple task as macrophages behave differently depending on the microenvironment. In agreement with this, non-consistent data have been reported regarding macrophages response to magnetic iron oxide nanoparticles (MNPs). To investigate the impact of both tissue microenvironment and MNPs properties on the obtained macrophage responses, single-core (SC) and multi-core (MC) citrate coated MNPs, are synthesized and, afterwards, loaded with a macrophage polarization trigger, IL-4. The developed MNPs are then tested in macrophages subjected to different stimuli. We demonstrate that macrophages treated with low concentrations of MNPs behave differently depending on the polarization stage independently of the concentration of iron. Moreover, we find out that MNPs size and morphology determines the effect of the IL-4 loaded MNPs on M1 macrophages, since IL-4 loaded SC MNPs favor the polarization of M1 macrophages towards M2 phenotype, while IL-4 loaded MC MNPs further stimulate the secretion of pro-inflammatory cytokines. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles (IONPs) have many practical applications, ranging from environmental protection to biomedicine. IONPs are being investigated due to their high potential for antimicrobial activity and lack of toxicity to humans. However, the biological activity of IONPs is not uniform and depends on the synthesis conditions, which affect the shape, size and surface modification. The aim of this work is to synthesise IONPs using a mixed method, i.e., chemical co-precipitation combined with biogenic surface modification, using extracts from spent hops (Humulus lupulus L.) obtained as waste product from supercritical carbon dioxide hop extraction. Different extracts (water, dimethyl sulfoxide (DMSO), 80% ethanol, acetone, water) were further evaluated for antioxidant activity based on the silver nanoparticle antioxidant capacity (SNPAC), total phenolic content (TPC) and total flavonoid content (TFC). The IONPs were characterised via UV-vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and Fourier-transform infrared (FT-IR) spectroscopy. Spent hop extracts showed a high number of flavonoid compounds. The efficiency of the solvents used for the extraction can be classified as follows: DMSO > 80% ethanol > acetone > water. FT-IR/ATR spectra revealed the involvement of flavonoids such as xanthohumol and/or isoxanthohumol, bitter acids (i.e., humulones, lupulones) and proteins in the surface modification of the IONPs. SEM images showed a granular, spherical structure of the IONPs with diameters ranging from 81.16 to 142.5 nm. Surface modification with extracts generally weakened the activity of the IONPs against the tested Gram-positive and Gram-negative bacteria and yeasts by half. Only the modification of IONPs with DMSO extract improved their antibacterial properties against Gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, Bacillus cereus) from a MIC value of 2.5–10 mg/mL to 0.313–1.25 mg/mL. [ABSTRACT FROM AUTHOR]

The utilization of nanoparticles to enhance bacterial activity and boost hydrogen production in fermentation processes has gained significant attention due to their unique properties such as high specific surface area and quantum size. This research aimed to improve the biohydrogen yield from food waste by adding iron oxide nanoparticles (Fe 3 O 4) at various concentrations (50, 75, 100, 150, and 200 mg/l) and titanium dioxide (TiO 2) at different amounts (25–150 mg/l) to a single-stage hybrid (dark/photo) fermentation reactor. After obtaining the optimal amount of these two nanoparticles, the effect of synergic addition of nanoparticles on hydrogen production yield, was investigated at ratios of Fe 3 O 4 /TiO 2 = 50/50 and 100/50 mg/mg. At the ratio of Fe 3 O 4 /TiO 2 = 100/50, the cumulative hydrogen production and yield of hydrogen have increased from 1613 to 3392 ml and 101.60 to 213.66 mlH 2 /gVS, respectively, compared to the control experiment. We also found that the COD removal rate has enhanced from 28% to 40.1%. In the optimal value, the bacterial growth lag phase has also remarkably decreased from 8.19 to 4.81 h. • Synergic application of TiO 2 and Fe 3 O 4 significantly increased biohydrogen purity and production yield. • TiO 2 played an important role in the activity of bacteria in the photo fermentation process. • Fe 3 O 4 played an important role in the dark fermentation system. • Nanoparticles may act as a scaffold for enzyme and substrate binding. • Optimal nanoparticle concentration may differ for different bioreactors. [ABSTRACT FROM AUTHOR]

Fluorine magnetic resonance imaging (19F MRI) has emerged as an attractive alternative to conventional 1H MRI due to enhanced specificity deriving from negligible background signal in this modality. We report a dual nanoparticle conjugate (DNC) platform as an aptamer‐based sensor for use in 19F MRI. DNC consists of core–shell nanoparticles with a liquid perfluorocarbon core and a mesoporous silica shell (19F‐MSNs), which give a robust 19F MR signal, and superparamagnetic iron oxide nanoparticles (SPIONs) as magnetic quenchers. Due to the strong magnetic quenching effects of SPIONs, this platform is uniquely sensitive and functions with a low concentration of SPIONs (4 equivalents) relative to 19F‐MSNs. The probe functions as a "turn‐on" sensor using target‐induced dissociation of DNA aptamers. The thrombin binding aptamer was incorporated as a proof‐of‐concept (DNCThr), and we demonstrate a significant increase in 19F MR signal intensity when DNCThr is incubated with human α‐thrombin. This proof‐of‐concept probe is highly versatile and can be adapted to sense ATP and kanamycin as well. Importantly, DNCThr generates a robust 19F MRI "hot‐spot" signal in response to thrombin in live mice, establishing this platform as a practical, versatile, and biologically relevant molecular imaging probe. [ABSTRACT FROM AUTHOR]

There are many nanoparticle preparation techniques such as the biological approach sol-gel method and physical methods, etc. However, the co-precipitation approach requires few chemical reagents and reaction time as well as produces highly pure products with comparatively lower costs among the available techniques. In present work co-precipitation method is use to synthesize magnetic iron oxide (Fe3O4) nanoparticles, followed by characterization to check its applicability and the presence of undesired substrate. UV–visible spectroscopy, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and Fourier-Transform Infrared Spectroscopy (FTIR) were examined to determine the synthesized Fe3O4 nanoparticles. The nanoparticles' sizes lies between 1 nm to 100 nm, according to the SEM and HR-TEM analyses. XRD measurements verified the crystalline characteristics of the Fe3O4 nanoparticles. Dielectric spectroscopy of synthesized Fe3O4 nanoparticle pellets has been investigated at a wide frequency range 0.1 to 105 Hz. Capacitance and dielectric permittivity of Fe3O4 nanoparticles decrease continuously with frequency as dipole gets less time to orient in the field. The dielectric permittivity of Fe3O4 pellets increases up to 3 mm thickness and subsequently drops, perhaps because a rise in resistance. The electrical conductivity of Fe3O4 rises exponentially with frequency. According to the dielectric studies, the dielectric permittivity and electrical conductivity of Fe3O4 are greatly dependent on the thickness and extent of frequency. Additionally, the dielectric impedance of Fe3O4 pellets has also been investigated as a function of frequency. [ABSTRACT FROM AUTHOR]

Bimetallic nanoparticles (BMNPs) combine unique and synergistic properties of two metals, allowing new specific applications. In this study, bimetallic AuFe nanoparticles and their conjugates with methotrexate (MTX) were obtained with an environmentally safe method of metal-vapor synthesis. The composition and electronic structure of the particles were investigated with X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX) spectrum and X-ray absorption spectroscopy (XANES and EXAFS). The effects of BMNP-MTX conjugates on human primary cells and tumor cell lines were evaluated with neutral red uptake and MTT in vitro cytotoxicity assays. Bright-field microscopy analyses of tumor spheroid size and evaluations of tumor spheroid vitality based on SFDA AM staining were carried out. In vitro assays for an antibacterial activity evaluation of the generated samples were performed. The influence of BMNP-MTX on cytokine production with normal leukocytes was assessed using ELISA. X-ray analyses of the samples demonstrated that gold was in the ground state Au0 as well as Au+ and Au3+ states are present in small quantities, whereas iron existed as a mixture of non-histometric oxides with states close to Fe2+ and Fe3+. The modification of the AuFe system with MTX is accompanied by a threefold increase in the relative proportion of the Au+ state. BMNP-MTX conjugates demonstrated significant antitumor activity compared to the drug alone, which proves the ability of the generated nanoconjugates to improve the effectiveness of MTX therapy. This was confirmed by a marked reduction in the size and vitality of AuFe-MTX-treated 3D tumor spheroids. In addition to their selective antitumor activity, AuFe-MTX exhibited moderate antibacterial activity and induced sample-specific cytokine production with normal human leukocytes—which points to an immunostimulatory potential. The present findings indicate important and diverse biological properties of BMNP-MTX conjugates and thus highlight perspectives for their biomedical applications and new immune-specific abilities. [ABSTRACT FROM AUTHOR]

A lot of nanomaterials have been applied to various nano-biotechnological fields, such as contrast agents, drug or gene delivery systems, cosmetics, and so on. Despite the expanding usage of nanomaterials, concerns persist regarding their potential toxicity. To address this issue, many scientists have tried to develop biocompatible nanomaterials containing phytochemicals as a promising solution. In this study, we synthesized biocompatible nanomaterials by using gallic acid (GA), which is a phytochemical, and coating it onto the surface of iron oxide nanoparticles (IONPs). Importantly, the GA-modified iron oxide nanoparticles (GA-IONPs) were successfully prepared through environmentally friendly methods, avoiding the use of harmful reagents and extreme conditions. The presence of GA on the surface of IONPs improved their stability and bioactive properties. In addition, cell viability assays proved that GA-IONPs possessed excellent biocompatibility in human dermal papilla cells (HDPCs). Additionally, GA-IONPs showed antioxidant activity, which reduced intracellular reactive oxygen species (ROS) levels in an oxidative stress model induced by hydrogen peroxide (H2O2). To investigate the impact of GA-IONPs on exosome secretions from oxidative stress-induced cells, we analyzed the number and characteristics of exosomes in the culture media of HDPCs after H2O2 stimulation or GA-IONP treatment. Our analysis revealed that both the number and proportions of tetraspanins (CD9, CD81, and CD63) in exosomes were similar in the control group and the GA-IONP-treated groups. In contrast, exosome secretion was increased, and the proportion of tetraspanin was changed in the H2O2-treated group compared to the control group. It demonstrated that treatment with GA-IONPs effectively attenuated exosome secretion induced by H2O2-induced oxidative stress. Therefore, this GA-IONP exhibited outstanding promise for applications in the field of nanobiotechnology. [ABSTRACT FROM AUTHOR]

Soil salinisation is one of the main abiotic stresses decreasing crop productivity. Here, we show that the plant treatment with iron oxide (Fe3O4) nanoparticles (NPs) may be a promising solution for reducing the negative impact of soil salinity on plant performance. For this purpose, effects of the NPs on growth, photosynthesis, pro-/antioxidant, redox balance and the content of mineral elements in 19-day-old wheat (Triticum aestivum) plants under soil salinity were studied. Seed treatment with NPs (200 and 500 mg L−1) enhanced growth and photosynthetic rate in leaves. Moderate salinity stress (150 mM NaCl) led to a decrease in plant biomass as well as the rate of photosynthesis and PSII activity; leaf photosynthetic characteristics were also suppressed by lower (75 mM NaCl) salinity treatment. However, seed pre-treatment with the NPs partially eliminated the negative effect of the salt on growth, PSII activity and photosynthesis. Also, we observed a decrease in the content of malondialdehyde (MDA) and an increase in ascorbate and total peroxidase activity in the plant leaves upon combined treatment with NaCl and the NPs compared with treatment with NaCl alone. The combined treatment with the NPs and salinity also led to a noticeable increase in the content of Fe and Mn in the shoot. It was concluded that Fe3O4 NPs can enhance plant growth by improving photosynthetic characteristics, antioxidant balance and the availability of iron and manganese ions, under conditions of soil salinisation. Soil salinity significantly affects productivity of agricultural systems. This work shows that plant treatment with iron oxide nanoparticles (Fe3O4 NPs) may be a promising solution for reducing the negative impact of soil salinity on plant performance. It is concluded that Fe3O4 NPs can enhance plant growth by improving photosynthetic characteristics, antioxidant balance and the availability of iron and manganese ions, under conditions of soil salinisation. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases and a major contributor to dementia. Although the cause of this condition has been identified long ago as aberrant aggregations of amyloid and tau proteins, effective therapies for it remain elusive. The complexities of drug development for AD treatment are often compounded by the impermeable blood–brain barrier and low-yield brain delivery. In addition, the use of high drug concentrations to overcome this challenge may entail side effects. To address these challenges and enhance the precision of delivery into brain regions affected by amyloid aggregation, we proposed a transferrin-conjugated nanoparticle-based drug delivery system. The transferrin-conjugated melittin-loaded L-arginine-coated iron oxide nanoparticles (Tf-MeLioNs) developed in this study successfully mitigated melittin-induced cytotoxicity and hemolysis in the cell culture system. In the 5XFAD mouse brain, Tf-MeLioNs remarkably reduced amyloid plaque accumulation, particularly in the hippocampus. This study suggested Tf-LioNs as a potential drug delivery platform and Tf-MeLioNs as a candidate for therapeutic drug targeting of amyloid plaques in AD. These findings provide a foundation for further exploration and advancement in AD therapeutics. [ABSTRACT FROM AUTHOR]

Background: Aquaculture is one of the most rapidly expanding food production sectors. Due to intensification, declining water quality parameters negatively impact fish production and the surrounding environment. Thus, it is essential to maintain optimum water quality parameters and aquatic ecosystems for sustainable fish production. This study aims to synthesize nanoparticles (NPs) and evaluate their efficiency against ammonia in cultured fish tanks under diverse conditions. Methods: Bacillus megaterium from the soil sample was isolated and identified. Iron oxide NPs were synthesized using Bacillus megaterium collected from soil samples and characterized by DLS-zeta potential, UV-Vis, XRD, FTIR and TEM analysis. Next, synthesized NPs were evaluated under ex-situ and in-situ conditions to determine their efficacy in removing ammonia from Common carp, Cyprinus carpio culture tanks. Result: B. megaterium was isolated, identified and 16S rRNA gene PCR-amplified sequences confirm the identification of B megaterium. DLS-zeta potential, UV-Vis, XRD, FTIR and TEM analysis revealed the quality of synthesized NPs. B. megaterium from the soil sample was isolated and identified. The mean zeta potential of the biosynthesized NPs was between -4.65 to -6.45 mV and had an average size of 5 nm. The concentration of ammonia in aerated tanks treated with iron NPs reduced to less than 0.03 mg/L from 0.3 mg/L. Also, fish mortality in these tanks was significantly controlled with the application of NPs. The application of NPs considerably reduced fish mortality in these fish tanks. Iron oxide NPs from B. megaterium can produce high-quality NPs that are efficient in removing ammonia from fish culture tanks. Further, exploratory studies are necessary to determine the efficacy of iron oxide NPs on aquatic organisms cultured in different environments. [ABSTRACT FROM AUTHOR]

Methylene blue (MB) is a hazardous chemical that is widely found in wastewater, and its removal is critical. One of the most common methods to remove MB is adsorption. To enhance the adsorption process, magnetic adsorbents, particularly those based on superparamagnetic iron oxide nanoparticles (SPION), play a vital role. This study focuses on comparing recent novel SPION-based MB adsorbents and how to acquire the critical parameters needed to evaluate the adsorption and desorption mechanisms, including isotherms, kinetics, and thermodynamic properties. Moreover, the review article also discusses the future aspects of these adsorbents. [ABSTRACT FROM AUTHOR]

Staging lymph nodes (LN) is crucial in diagnosing and treating cancer metastasis. Biotechnologies for the specific localization of metastatic lymph nodes (MLNs) have attracted significant attention to efficiently define tumor metastases. Bioimaging modalities, particularly magnetic nanoparticles (MNPs) such as iron oxide nanoparticles, have emerged as promising tools in cancer bioimaging, with great potential for use in the preoperative and intraoperative tracking of MLNs. As radiation-free magnetic resonance imaging (MRI) probes, MNPs can serve as alternative MRI contrast agents, offering improved accuracy and biological safety for nodal staging in cancer patients. Although MNPs' application is still in its initial stages, exploring their underlying mechanisms can enhance the sensitivity and multifunctionality of lymph node mapping. This review focuses on the feasibility and current application status of MNPs for imaging metastatic nodules in preclinical and clinical development. Furthermore, exploring novel and promising MNP-based strategies with controllable characteristics could lead to a more precise treatment of metastatic cancer patients. [ABSTRACT FROM AUTHOR]

Iron oxide (FeO) nanoparticles have gained considerable interest from researchers over the past few decades and have a massive effect on wave absorption materials, magnetic fluid, adsorbent, and a variety of industrial applications. In this study, ferric nitrate, sodium hydroxide, and ammonium hydroxide coalesced to form FeO nanoparticles using the chemical co-precipitation approach. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), UV-VIS analysis, Photoluminesence (PL) spectrum analysis, and electrochemical measurements were used to characterize FeO nanoparticles. As per XRD, the sample's crystallite size was 22.63 nm and 22.64 nm after it was annealed at 300∘C and 400∘C, respectively. Utilizing XRD, the diffraction patterns were seen. The particles appear to have a fine surface and smooth shape, as seen by SEM photographs. For the detection of FeO nanoparticles, optical and electrochemical examinations were carried out. [ABSTRACT FROM AUTHOR]

Different nanoparticles of iron oxides (Fe2O3 and Fe3O4 ) were prepared by the hydrothermal method. These nanoparticles were heated at 90°C and at 400°C. The morphology and structures of the heated samples were characterized using different measurements such as FT-IR, UV-visible, scanning electron microscopy (SEM), atomic force microscope (AFM), and X-ray diffraction (XRD). The enzyme activity (nanozymes), mimicking acetylcholine esterase (AChE), was measured. The results showed that the maximum of nanozyme activity as AChE relates to Fe3O4 heated at 90°C, and this activity becomes the lowest, when Fe3O4 is heated at 400°C. While Fe2O3 heated at 90°C showed less activity than the sample heated at 400°C, this may be because both Fe3O4 heated at 90°C and Fe2O3 is heated at 400°C have magnetic properties, and when those properties are lost, the activity decreases. [ABSTRACT FROM AUTHOR]

Produced water has a considerable amount of oil that can harm the environment if dumped prior to treatment. Iron oxide (maghemite) nanoparticles have attracted much attention as potential adsorbents due to their unique properties, high adsorption capacity, super magnetization, and high surface area. In this study, maghemite 3 nm and 15–20 nm have been used as adsorbents. Oil has been successfully removed from oil-water emulsion using maghemite with the application of a magnetic field. The effects of the varying process parameters, including adsorbent dose, particle size, mixing time, API, pH, temperature, and oil concentration, on the percentage of oil removal (OR%) were studied. The highest OR% was achieved at 20 min, 100 mg/L oil concentration, 80 mg adsorbent dose, room temperature, 30 API, and pH 6; these data were taken as a reference to evaluate the other parameters. The highest ORs% were 94% and 83% for MNPs of 3 nm and 15–20 nm, respectively. Stability and reusability tests of the maghemite exhibited an effective oil recovery of up to 77% and 64% after 9 cycles. They displayed a maximum adsorption capacity of 3280 mg/g and 3235 mg/g for the 3 nm and 15–20 nm nanoparticles, respectively. The Langmuir isotherm model showed a better fit with experimental data compared to the Freundlich-isotherm model. Kinetic adsorption models fit effectively with the pseudo-second-order model. Thus, the results demonstrate maghemite nanoparticles' efficiency in removing oil from oil-water emulsions. This innovative technique will reduce time and optimize the conventional treatment process. [ABSTRACT FROM AUTHOR]

An advanced version of the solution combustion synthesis (SCS) method was developed to prepare iron oxide (IO) nanoparticles, through controlling the agglomeration, size and shape of nanoparticles by assisting a cationic surfactant, "cetyltrimethylammonium bromide (CTAB)" and ethanol. Various IO nanoparticles were prepared in the presence of different CTAB:ethanol molar compositions of 0:0, 0.27:0, 0.55:0, 0.27:17.1, 0.55:17.1 and 0.82:17.1. The morphological evolution from agglomerated-shape particles to the well-dispersed as well as the size- and shape-controlled particles depended directly on the CTAB:ethanol molar composition. A shift from ferromagnetic behavior to superparamagnetic was observed by the application of CTAB along with ethanol, where the lowest blocking temperature (T b , 60 K), highest saturation magnetization (M s , 83.5 emu g−1), zero coercivity and remanance magnetization were revealed for the particles prepared by CTAB:ethanol molar compositions of 0.55:17.1. These particles showed an acceptable specific absorption rate (SAR) value (320 W g−1) as well as no obvious hemolytic and cytotoxic effects. This work provides new insights into advancing the SCS method and thus controlling the morphology, size and shape of metal oxide nanoparticles. [Display omitted] • Controlling the agglomeration, size and shape of nanoparticles in SCS method. • Structural and magnetic properties of particles depended on the CTAB:ethanol ratio. • The agglomerated-free, size- and shape-controlled IO-EC2 structure was developed. • IO-EC2 represented an acceptable SAR value, and no hemolytic and cytotoxic effects. [ABSTRACT FROM AUTHOR]

Octylamine (OTA), 1-dodecanethiol (DDT), and tri-n-octylphosphine (TOP) capped magnetite nanoparticles were prepared by co-precipitation method. Powder X-ray diffraction patterns confirmed inverse spinel crystalline phases for the as-prepared iron oxide nanoparticles. Transmission electron microscopic micrographs showed iron oxide nanoparticles with mean particle sizes of 2.1 nm for Fe3O4-OTA, 5.0 nm for Fe3O4-DDT, and 4.4 nm for Fe3O4-TOP. The energy bandgap of the iron oxide nanoparticles ranges from 2.25 eV to 2.76 eV. The iron oxide nanoparticles were used as photocatalysts for the degradation of methylene blue with an efficiency of 55.5%, 58.3%, and 66.7% for Fe3O4-OTA, Fe3O4-DDT, and Fe3O4-TOP, respectively, while for methyl orange the degradation efficiencies were 63.8%, 47.7%, and 74.1%, respectively. The results showed that tri-n-octylphosphine capped iron oxide nanoparticles are the most efficient iron oxide nano-photocatalysts for the degradation of both dyes. Scavenger studies show that electrons (e−) and hydroxy radicals (•OH) contribute significantly to the photocatalytic degradation reaction of both methylene blue and methyl orange using Fe3O4-TOP nanoparticles. The influence of the dye solution's pH on the photocatalytic reaction reveals that a pH of 10 is the optimum for methylene blue degradation, whereas a pH of 2 is best for methyl orange photocatalytic degradation using the as-prepared iron oxide nano-photocatalyst. Recyclability studies revealed that the iron oxide photocatalysts can be recycled three times without losing their photocatalytic activity. [ABSTRACT FROM AUTHOR]

Objective: The main objectives of this study was to prepare and study the structural features of chitosan/iron oxide nanoparticles CS-FeO NPs and to examine the applications of chitosan nanoparticles as a lipid-lowering agent in children with nephrotic syndrome Method: The preparation processes for nanoparticles are described in depth. Chitosan nanoparticle applications are shown. X-ray diffraction patterns (XRD) indicated that the magnetic Fe3O4 nanoparticles were pure Fe3O4 with a spinel structure and the coating of chitosan did not result in a phase change. Results: The coating of CTS onto the Fe3O4 nanoparticles was also demonstrated by the measurement of Fourier transform infrared (FTIR) spectra. Magnetic measurement revealed that the saturated magnetization of the Fe3O4--chitosan nanoparticles reached +18.3 mV and the nanoparticles showed the characteristics of superparamagnetic. Conclusion: Magnetic Fe3O4--chitosan nanoparticles were prepared successfully by the covalent binding of CTS on the Fe3O4 nanoparticles. These microspheres was apply to the magnetic-field-assisted lipid lowering processes. [ABSTRACT FROM AUTHOR]

Highly active, stable, and cut-price (photo-)electrocatalysts are desired to overwhelm high energy barriers for anodic oxygen evolution reaction processes. Herein, a heterostructure of cobalt-iron oxide/black phosphorus nanosheets is in-situ synthesized via a facile and novel three-electrode electrolysis method. Bulky black phosphorus is exfoliated into its nanosheets at the cathode while the CoFe oxide is derived directly from the metal wire anode during the electrolysis process. This heterostructure exhibits excellent electrocatalytic oxygen evolution reaction (OER) performance, and the overpotential at 10 mA·cm−2 is 51 mV lower than that of the commercial RuO2 catalyst. Its superior OER performance stems from the favorable adsorption behavior and an enlarged electrochemical active surface area of the catalyst. To reveal the origin of excellent OER performance from the point of adsorption strength of OH*, methanol oxidation reaction (MOR) test is applied under the identified OER operating conditions. Further introduction of light illumination enhances the OER activity of this heterostructure. The overpotential drops down to 280 mV, benefiting from pronounced photochemical response of black phosphorus nanosheets and iron oxide inside the heterostructure. This work develops a new electrochemical method to construct high performance and light-sensitive heterostructures from black phosphorus nanosheets for the OER. [ABSTRACT FROM AUTHOR]

In environmental and agronomic settings, even minor imbalances can trigger a range of unpredicted responses. Despite the widespread use of metal-based nanoparticles (NPs) and new bio-nanofertilizers, their impact on crop production is absent in the literature. Therefore, our research is focused on the agronomic effect of spray application of gold nanoparticles anchored to SiO2 mesoporous silica (AuSi-NPs), zinc oxide nanoparticles (ZnO-NPs), and iron oxide nanoparticles (Fe3O4-NPs) on sunflowers under real-world environments. Our findings revealed that the biosynthetically prepared AuSi-NPs and ZnO-NPs were highly effective in enhancing sunflower seasonal physiology, e.g., the value of the NDVI index increased from 0.012 to 0.025 after AuSi-NPs application. The distribution of leaf trichomes improved and the grain yield increased from 2.47 t ha−1 to 3.29 t ha−1 after ZnO-NPs application. AuSi-NPs treatment resulted in a higher content of essential linoleic acid (54.37%) when compared to the NPs-free control (51.57%), which had a higher determined oleic acid. No NPs or residual translocated metals were detected in the fully ripe sunflower seeds, except for slightly higher silica content after the AuSi-NPs treatment. Additionally, AuSi-NPs and NPs-free control showed wide insect biodiversity while ZnO-NPs treatment had the lowest value of phosphorus as anti-nutrient. Contradictory but insignificant effect on physiology, yield, and insect biodiversity was observed in Fe3O4-NPs treatment. Therefore, further studies are needed to fully understand the long-term environmental and agricultural sustainability of NPs applications. [ABSTRACT FROM AUTHOR]

Cancer—one of the most life-threatening human diseases—can be treated with surgery, chemotherapy, and radiotherapy. Despite the negative side effects, conventional chemotherapy which contains doxorubicin is widely used in cancer treatment. Drug delivery carriers, an alternative cancer treatment, can be used to target tumor site by vectorizing anti-cancer drug and minimize the drug quantities. Due to unique physical and chemical properties, superparamagnetic iron oxide nanoparticles are researched and documented. This work investigates how magnetic drug delivery carriers are synthesized, how the carriers are characterized and quantified, the mechanisms of drug loading/releasing of the carriers including kinetics and thermodynamic parameters, and the future research topics of magnetic drug delivery carriers for loading and releasing doxorubicin. [ABSTRACT FROM AUTHOR]

Nanocomposites formed of natural-origin iron oxide nanoparticles (magnetite and maghemite, Fe3O4 and ?-Fe2O3, respectively) were processed using the solgel process into core-shell structures containing silica and samarium to investigate their potential for applications in cancer treatments combining hyperthermia and brachytherapy. Mössbauer characterization showed that the iron oxides contained 64% magnetite, 18% hematite, 12% maghemite, and exhibit superparamagnetic behavior at room temperature. Transmission electron microscopy determined that the iron oxide particles were smaller than 15 nm, while magnetization was measured at 5 emu/g. Fourier transform infrared indicated the material was formed of Si-O-Si and Fe-O-Si bonds, while X-ray diffraction showed bands of amorphous silica from 5° to 23° and bands of iron oxide phases. X-ray fluorescence indicated 5.17% of incorporated samarium. The nanocomposite suspensions were subjected to an alternating magnetic field and the resulting heat dissipation was measured, falling within the ideal range for hyperthermia applications. Theoretical dosimetric calculation determined significant radioactive activity of 1.68x10-8 MBq.mg-1.F -1 after 24h decay time for 153Sm. The characteristics and behavior of these nanocomposites indicate that they may offer promise in applications involving hyperthermia for cancer treatment and a more accessible source for brachytherapy materials. [ABSTRACT FROM AUTHOR]

These dyes have the potential for mutagenicity, carcinogenicity, and unwanted color on the one hand, and on the other hand, cause the production of toxic by-products in aqueous media. The aim of the present work is to synthesize scallop shell/iron oxide(II) nanocomposite and evaluate its efficiency in removing Direct red 81 (DR81) dye from aqueous solutions. Iron oxide nanoparticles were prepared by co-precipitation method and then the scallop was coated with iron oxide. The properties of synthesized nanocomposite were identified using Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, and X-ray diffraction. Effect of dye concentration (20–120 mg/L), contact time (0–240 min), adsorbent dosage (0.5–2.5 g), pH (3–11), and temperature (25°C–55°C) was investigated on decolorization efficiency of the process. Under optimal conditions (an initial DR81 concentration of 25 mg/L, pH of 3, adsorbent dose of 0.5 g, and contact time of 90), more than 98% of the dye was removed. The results showed that the efficiency decreases with increasing concentration. Moreover, by increasing the contact time and adsorbent dosage, dye adsorption percentage was enhanced. The maximum adsorption coefficient was 46.4 mg/g. In addition, Freundlich and Langmuir models were used to analyze the experimental isotherm data. The kinetic data of the adsorption process were in good agreement with the pseudo-secondorder kinetic model (0.995). The experimental data of the adsorption process followed the Langmuir model (R² = 0.91). The results show that Fe2 O3 nanoparticles coated with scallop shell as an environmentally friendly adsorbent can be effective in the adsorption of DR81. [ABSTRACT FROM AUTHOR]

Electrocoagulation is an evolving technology for the abatement of a broad range of pollutants in wastewater owing to its flexibility, easy setup, and eco-friendly nature. Here, environment-friendly strategies for the separation, retreatment, and utilization of microplastics via electrocoagulation are investigated. The findings show that the flocs generated by forming Fe3O4 on the surface of polyethylene (PE) particles are easily separated using a magnetic force with high efficiency of 98.4%. In the photodegradation of the obtained flocs, it is confirmed that Fe3O4 shall be removed for the efficient generation of free radicals, leading to the highly efficient photolysis of PE. The removed Fe3O4 can be recycled into iron-oxalate compounds, which can be used in battery applications. In addition, it is suggested that heat treatment of Fe3O4-PE flocs in an Ar atmosphere leads to forming Fe3O4 core-carbon shell nanoparticles, which show excellent performance as anodes in lithium-ion batteries. The proposed composite exhibits an excellent capacity of 1123 mAh g-1 at the current density of 0.5 A g-1 after 600 cycles with a negative fading phenomenon. This study offers insight into a new paradigm of recyclable processes, from environmental issues such as microplastics to using energy materials. [ABSTRACT FROM AUTHOR]

Nowadays, antioxidants and antibacterial activity play an increasingly vital role in biosystems due to the biochemical and biological reactions that involve free radicals and pathogen growth, which occur in many systems. For this purpose, continuous efforts are being made to minimize these reactions, including the use of nanomaterials as antioxidants and bactericidal agents. Despite such advances, iron oxide nanoparticles still lack knowledge regarding their antioxidant and bactericidal capacities. This includes the investigation of biochemical reactions and their effects on nanoparticle functionality. In green synthesis, active phytochemicals give nanoparticles their maximum functional capacity and should not be destroyed during synthesis. Therefore, research is required to establish a correlation between the synthesis process and the nanoparticle properties. In this sense, the main objective of this work was to evaluate the most influential process stage: calcination. Thus, different calcination temperatures (200, 300, and 500 °C) and times (2, 4, and 5 h) were studied in the synthesis of iron oxide nanoparticles using either Phoenix dactylifera L. (PDL) extract (green method) or sodium hydroxide (chemical method) as the reducing agent. The results show that calcination temperatures and times had a significant influence on the degradation of the active substance (polyphenols) and the final structure of iron oxide nanoparticles. It was found that, at low calcination temperatures and times, the nanoparticles exhibited small sizes, fewer polycrystalline structures, and better antioxidant activities. In conclusion, this work highlights the importance of green synthesis of iron oxide nanoparticles due to their excellent antioxidant and antimicrobial activities. [ABSTRACT FROM AUTHOR]

Background: The role of tumor-associated macrophages (TAMs) in glioblastoma (GBM) disease progression has received increasing attention. Recent advances have shown that TAMs can be re-programmed to exert a pro-inflammatory, anti-tumor effect to control GBMs. However, imaging methods capable of differentiating tumor progression from immunotherapy treatment effects have been lacking, making timely assessment of treatment response difficult. We showed that tracking monocytes using iron oxide nanoparticle (USPIO) with MRI can be a sensitive imaging method to detect therapy response directed at the innate immune system. Methods: We implanted syngeneic mouse glioma stem cells into C57/BL6 mice and treated the animals with either niacin (a stimulator of innate immunity) or vehicle. Animals were imaged using an anatomical MRI sequence, R2* mapping, and quantitative susceptibility mapping (QSM) before and after USPIO injection. Results: Compared to vehicles, niacin-treated animals showed significantly higher susceptibility and R2*, representing USPIO and monocyte infiltration into the tumor. We observed a significant reduction in tumor size in the niacin-treated group 7 days later. We validated our MRI results with flow cytometry and immunofluoresence, which showed that niacin decreased pro-inflammatory Ly6C high monocytes in the blood but increased CD16/32 pro-inflammatory macrophages within the tumor, consistent with migration of these pro-inflammatory innate immune cells from the blood to the tumor. Conclusion: MRI with USPIO injection can detect therapeutic responses of innate immune stimulating agents before changes in tumor size have occurred, providing a potential complementary imaging technique to monitor cancer immunotherapies. Manuscript highlight: We show that iron oxide nanoparticles (USPIOs) can be used to label innate immune cells and detect the trafficking of pro-inflammatory monocytes into the glioblastoma. This preceded changes in tumor size, making it a more sensitive imaging technique. [ABSTRACT FROM AUTHOR]

A low-cost and efficient adsorbent for arsenic removal from drinking water is fabricated using rice husk ash (RHA) and iron oxide nanoparticles. The carbonization of rice husk biomass obtains the RHA at 600 °C under deoxygenated conditions. In contrast, the iron oxide nanoparticles are prepared by the wet chemical method. The physicochemical properties of iron oxide modified RHA adsorbent is characterized by using FTIR, SEM, EDX, and N2 adsorption–desorption. The FTIR results reveal the presence of magnetite, hematite, and silica oxide in the adsorbent. SEM images show that the adsorbent has a rough, porous, and tubular structure with embedded iron oxide nanoparticles in RHA. Element analysis and BET surface area further confirm the iron oxide modification of the RHA adsorbent. RHA and iron oxide modified RHA adsorbents are employed to remove arsenic from drinking water through the adsorption process. The fabricated adsorbent was converted into a purification cartridge with a 100 mL/min flow rate and tried a groundwater sample with arsenic contamination of 40 ppm. A − 98% of the removal of arsenic metal is observed. In addition, various adsorption parameters such as pH, time, adsorbent dose, and metal concentration are optimized. Under optimized parameters, the adsorption capacity of iron oxide modified rice husk was 25.06 mg/g. The adsorption kinetics data are plotted using the Langmuir and Freundlich isotherms, and pseudo-first-order kinetics is observed. The stability of the adsorbent is examined by reusing it, and no significant difference is kept in its adsorption efficiency. [ABSTRACT FROM AUTHOR]

Background and Objectives: The interaction between nanoparticles (NPs) and viruses is attracting interest because of the antiviral potential of NPs. This study aims to investigate the antiviral potential of NPs against Herpes simplex virus types 1 (HSV-1). Materials and Methods: Molecular docking studies were conducted by Molegro virtual docker software. An extract of Juglans regia green husk was utilized to biosynthesize copper-oxide nanoparticles (CuNPs). The cytotoxicity of NPs was evaluated by MTT assay. Different treatment assays were conducted. Another assay was designed to employ the concentration of 300 µg/ml of CuNPs, which is the highest concentration that did not precipitate. Finally, chemically synthesized Iron oxide nanoparticles (FeNPs) were utilized to adsorb CuNPs. The antiviral effect of FeNPs was investigated, separately. Results: Docking results confirmed that NPs could interact with the HSV-1 glycoproteins and prevent viral entry. MTT assay results illustrated that the minimum non-toxic concentration (MNTD) of CuNPs is 100 µg/ml which did not exhibit antiviral properties. Employing a noncytotoxic concentration of FeNPs (300 mg/ml) in combination with cytotoxic concentration of CuNPs (300 µg/ml), eliminated the cytotoxicity effects of CuNPs. Exposure of the virus with the combination of CuNPs and FeNPs resulted in 4.5 log10 TCID50 reductions in HSV-1. While treating HSV-1 with only FeNPs reduced the titer of virus by 3.25 log10 TCID50. Conclusion: The results highlight that combination of CuNPs and FeNPs have antiviral activity against HSV-1. Moreover, FeNPs demonstrated antiviral properties against HSV-1 separately. [ABSTRACT FROM AUTHOR]