Iron Nanoparticles Research Articles

Green synthesis and optimization of iron oxide nanoparticles as MRI contrast agent

Iron nanoparticles (FeNPs) derived from herbal plants are being explored as potential magnetic resonance imaging (MRI) contrast agents due to their biocompatibility and ability to perform targeted drug delivery. For the first time, the usage of various novel combinations of leaf extracts such as those of Azadirachta indica and Piper betle and extracts of two other Ayurvedic herbs – namely, Asparagus racemosus and Symplocos – was attempted for eco-friendly green synthesis of FeNPs. The nanoparticles were coated onto nanofibers made from a banana pseudo-stem (FENPs-NF) to enhance their biocompatibility. The synthesis process was optimized using response surface methodology, and techniques such as ultraviolet–visible (UV–Vis) spectroscopy, vibrating-sample magnetometry, atomic absorption spectroscopy (AAS), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FT-IR) were used for characterization. Hemolytic and immune cell assays, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and MRI analysis were carried out. A peak at 325 nm observed in UV–Vis spectroscopy, AAS, FE-SEM, EDX and FT-IR proved the presence of FeNPs. Hemolytic and immune cell assays indicated biocompatibility, and the MTT assay (MCF-7) showed inhibition at 250 μg/ml. FeNPs and FeNPs-NF showed a good signal loss in MRI analysis at 1.5 T, proving their contrast agent nature. Thus, FeNPs synthesized from herbal plant sources may open a new door for potential application in the biomedical field as a chemical-free and biocompatible MRI contrast agent.

Alteration in the Raman spectra of characteristic rock‐forming silicate mixtures due to micrometeorite bombardment

AbstractInnovative techniques are required for the in situ investigation of the surfaces of planetary bodies when landings are planned. Raman spectroscopy turned out as an excellent tool for fast mineralogical analyses on space missions. Contribution from a photoluminescence signal is not unexpected and is likely to be even more pronounced on celestial surfaces with a dilute or absent atmosphere exposed to strong space weathering, for example, micrometeorite bombardment. Such signals were found, for example, in Raman analysis of the probes from sample‐return missions. While photoluminescence is generally considered as an accompanying undesired product in the Raman spectral measurement, our studies show that some analytical information can be derived from this signal, and even more, due to the specific correlation of luminescence intensity with space weathering products. Therefore, we investigate the Raman spectra alteration of characteristic rock‐forming mineral mixtures (olivine, pyroxene and plagioclase) by micrometeorite bombardment, which is simulated by nanosecond‐pulse laser irradiation. The changes in the minerals are strongly dependent on the composition and structure. They range from disappearing changes in the minerals with simple chemistry and structure to complete amorphization of minerals with relatively low melting enthalpy. With Raman spectroscopy, we found out that the photoluminescence signals show resonant or anti‐resonant changes to specific mineral phases and amorphization. Furthermore, ablation‐induced iron nanoparticles of minerals containing Fe are detectable by Raman spectroscopy due to their alteration into iron oxides. Trapped volatiles in the matrices are analysed due to the formation of the compounds containing them. This broad spectrum of results indicating specific change phenomena due to space weathering can be effectively used for in situ Raman analysis in planetary missions.

A multiparametric study for size and stability of hybrid Fe 2 O 3 -NiO nanoparticles and their statistical transformation

A multiparametric study for size and stability of hybrid Fe ₂ O ₃ -NiO nanoparticles and their statistical transformation

Enhanced tetracycline degradation through nonradical processes by modulating the exposure of active sites on the iron nanoconfined catalysts

There is an urgent need to develop effective and sustainable methods for reducing water pollution. Non-homogeneous Fenton catalysts are commonly used to eliminate pollutants from water. However, the effectiveness of these catalysts is limited by the restricted availability and accessibility of the active site (AS). In this work, we presented a strategy for modulating the exposure of active nanometallic particles to fully expose the AS at the nanoscale. We also confined the AS in carbon frameworks with micropores and mesopores to enhance the effectiveness of AS utilization in Fenton-like reactions. The experimental results indicate that the Fe-out@N-C/PMS system achieved complete degradation of tetracycline within 10 min and maintained an efficient degradation rate of over 91% after five consecutive cycles. The degradation of contaminants was due to an effective non-radical mechanism, as shown by free radical quenching experiments, EPR reactive species capture tests, in situ Raman, and PMSO probe experiments. Furthermore, density-functional theory (DFT) calculations revealed that iron nanoparticles supported on nitrogen-doped carbon acted as active sites, enhancing electron transfer capacity (N-C (0.24 e) vs. Fe-out@N-C (0.69 e)). Finally, the intermediates have a limited environmental impact because of their extremely low concentrations, despite having a high relative toxicity. The exposed metal nanoparticle catalysts provide a new approach for effectively activating PMS to efficiently degrade organic contaminants with a high mineralization rate via the non-radical pathway.

Iron nanoparticles in combination with other conventional Fe sources remediate mercury toxicity-affected plants and soils by nutrient accumulation in bamboo species

The issue of mercury (Hg) toxicity has recently been identified as a significant environmental concern, with the potential to impede plant growth in forested and agricultural areas. Conversely, recent reports have indicated that Fe, may play a role in alleviating HM toxicity in plants. Therefore, this study's objective is to examine the potential of iron nanoparticles (Fe NPs) and various sources of Fe, particularly iron sulfate (Fe SO4 or Fe S) and iron-ethylene diamine tetra acetic acid (Fe - EDTA or Fe C), either individually or in combination, to mitigate the toxic effects of Hg on Pleioblastus pygmaeus. Involved mechanisms in the reduction of Hg toxicity in one-year bamboo species by Fe NPs, and by various Fe sources were introduced by a controlled greenhouse experiment. While 80 mg/L Hg significantly reduced plant growth and biomass (shoot dry weight (36%), root dry weight (31%), and shoot length (31%) and plant tolerance (34%) in comparison with control treatments, 60 mg/L Fe NPs and conventional sources of Fe increased proline accumulation (32%), antioxidant metabolism (21%), polyamines (114%), photosynthetic pigments (59%), as well as root dry weight (25%), and shoot dry weight (22%), and shoot length (22%). Fe NPs, Fe S, and Fe C in plant systems substantially enhanced tolerance to Hg toxicity (23%). This improvement was attributed to increased leaf-relative water content (39%), enhanced nutrient availability (50%), improved antioxidant capacity (34%), and reduced Hg translocation (6%) and accumulation (31%) in plant organs. Applying Fe NPs alone or in conjunction with a mixture of Fe C and Fe S can most efficiently improve bamboo plants' tolerance to Hg toxicity. The highest efficiency in increasing biochemical and physiological indexes under Hg, was related to the treatments of Fe NPs as well as Fe NPs + FeS + FeC. Thus, Fe NPs and other Fe sources might be effective options to remove toxicity from plants and soil. The future perspective may help establish mechanisms to regulate environmental toxicity and human health progressions.

Exploring the impact of organic and inorganic amendments, with foliar application of iron nanoparticles, on cadmium stabilization and growth of maize in wastewater irrigated-soil

ObjectivesThis study addresses the critical issue of Cd contamination in agricultural soils, posing substantial risks to crop productivity and food safety. While prior pot experiment has undertook this issue on a small scale, this study aims to evaluate the efficacy of selected best soil amendments, at a large-scale field experiment. MethodologyPress mud and humic acid were applied at 0.5%, while gypsum and Fe2O3 were applied at 5 mg/kg alone and with foliar application of Fe nanoparticles at 5 mg/L. AnalysisComparative analysis with control revealed the immobilization efficiency of all amendments in descending order of effectiveness as follows: 100, 102, 104, 104, 105, 102, 105, and 105% for PM, HA, GYP, Fe, PM + Fe Nps, HA + Fe Nps, GYP + Fe Nps, and Fe + Fe Nps. Additionally, reduced growth, photosynthetic activities, and elevated levels of malondialdehyde and hydrogen peroxide, indicative of oxidative damage in control plant. FindingsApplication of these amendments with foliar spraying of Fe Nps effectively mitigates Cd toxicity in maize crops, leading to improved growth, biomass, photosynthetic pigments, and antioxidant enzyme activities. Novelty/ImprovementThese findings highlight the significance of exploring innovative approach of combining different amendments with foliar application of nanoparticles to mitigate Cd contamination and enhance soil health, thereby contributing to global efforts in ensuring food safety and security.

Catalytic CO2 hydrogenation to hydrocarbon fuels in a potassium ion-conducting reactor

The electrochemically assisted CO2 hydrogenation directly to hydrocarbon fuels was studied, apparently for the first time, over a cheap, widespread and non-precious Fe catalyst in a potassium ion conducting (K-β-Al2O3) reactor, under atmospheric pressure, at relatively low temperatures and using representative concentrated CO2 and H2 gas mixtures and an easily scalable tubular catalyst-electrode configuration. The Fe electrocatalytic film was deposited by dip-coating on a commercial K-β-Al2O3 candle and characterized, both as prepared and after activation and testing, by TPR, TGA, XPS, XRD and SEM-EDX. The optimum operating conditions for both Fe activation (300 ºC, 75% H2, 24 hours) and electropromoted CO2 hydrogenation (300 ºC, 1.5 V, H2/CO2=3) were identified. Long-term tests on electrochemically promoted CO2 hydrogenation to hydrocarbons were performed under selected operating conditions to assess electrocatalyst stability. Both the selectivity to the target product (C5+ hydrocarbons) and the stability of the catalyst can be tuned in situ by modifying the potassium surface coverage via electrochemical pumping of potassium ions through the applied polarization. Finally, as an attempt to improve the catalyst-electrode behaviour, powdered catalysts, based on iron nanoparticles dispersed on KVO3 (a K+ and e- co-conductor) with different Fe loadings (17 and 9 wt%) were prepared and comparatively studied for CO2 hydrogenation to hydrocarbons. The catalyst with higher Fe loading was selected as the most promising, in terms of activity, selectivity and stability, for further catalyst-electrode optimisation by deposition, via dip-coating, of a Fe-KVO3 film on the K-β-Al2O3 candle.

Bio-fabrication and Characterization of Green Synthesized Nanoparticles from Commercial Honey

Green approaches to nanoparticle synthesis offer sustainable and environmentally friendly alternatives, avoiding hazardous chemicals typical in traditional methods. This study characterizes nanoparticles (NPs) synthesized from silver nitrate (AgNO3) and iron oxide (Fe2O3) using commercial honey as a reducing and capping agent. Characterization revealed significant disparities between silver NPs (AgNPs) and iron NPs (FeNPs). AgNPs had a larger particle size (Z-average: 3115.67 nm) compared to FeNPs (Z-average: 1813 nm). AgNPs showed a monodisperse population, while FeNPs had a slightly broader size distribution. Additionally, AgNPs had a higher particle concentration (mean count rate: 505.17 kcps) than FeNPs (mean count rate: 296.65 kcps). Both AgNPs and FeNPs displayed negative surface charges, at -6.499 mV and -1.652 mV, respectively, where FeNPs exhibit a slightly higher value. Elemental composition analysis by scanning electron microscope – energy dispersive X-ray (SEM-EDX) revealed that AgNPs are primarily composed of silver, carbon, and oxygen, whereas FeNPs consisted mainly of iron, oxygen, and carbon. These findings provide insights into the physical and chemical properties of AgNPs and FeNPs synthesized using commercial honey. Understanding these properties is essential for optimizing synthesis processes and exploring applications in medicine, catalysis, and environmental remediation. The eco-friendly synthesis approach using honey underscores the potential for sustainable nanomaterial production. Further research can explore specific applications and benefits of AgNPs and FeNPs synthesized through this green method, offering an efficient and economical alternative for nanoparticle synthesis.

Green synthesis of copper and iron nanoparticles from extracts of eucalyptus with their antimicrobial activities

Eco-friendly iron and copper nanoparticles were synthesized using masquerade and eucalyptus leaves extract as a reducing and stabilizing agents. Iron chloride heptahydrate (FeCl2.7H2O) and Copper sulphatepenta hydrate (CuSO4.5H2O) as metal precursors. It was characterized using UV visible, FTIR, XRD and SEM analysis. The UV result shows the highest peaks at 500 and 600 nm for iron and copper respectively. This is due to the surface plasma vibration of the phytochemical constituents present in the extract. FTIR shows presence of alkanoids and triterpenes, SEM shows the spherical granular with no well-defined morphology and mono dispersed structures for iron and copper nanoparticles respectively. It shows good antibacterial activity when tested against Escherichia-coli and Pseudomonas auredinosa (gram- negative), Staphylococcus aureus and Klebsella pneumonia (gram-positive).

Green synthesis of iron nanoparticles using Pistacia-atlantica leaf extract for enhanced removal of Cr(VI) from aqueous solution

The discharge of chromium-containing wastewater from various industries into aqueous environments is regarded as an important and challengeable matter due to its high toxicity. The application of conventional methods for eliminating this pollutant are often very expensive and difficult. Therefore, the adsorption process has been introduced as a desirable and effective method for removing chromium ions from aqueous media. In this research, iron nanoparticles (Fe-NPs) were synthesized using Pistacia-atlantica leaf extract as a reducing agent, then they were characterized by DLS, XRD, FT-IR, FESEM/EDS, and TEM techniques and its effectiveness to eliminate hexavalent chromium (Cr (VI)) from aqueous solutions was carried out. The capability of the batch adsorption procedure was assessed under different operational factors, such as initial pH, adsorbent dose and initial Cr (VI) concentration. Optimum adsorption conditions were determined at initial pH of 2, Cr (VI) concentration of 25mgL-1 and adsorbent dose of 0.24gL-1. Based on the obtained results, the highest removal efficiency (99.9%) by the adsorption process was occurred at pH of 2, concentration of 5mgL-1 and 30min of operational time. On the other hand, the results showed that the percentage of the pollutant elevated by increasing the contact time and amount of adsorbent dose, whereas that of was declined by increasing the initial concentration of Cr (VI). Besides, the experimental equilibrium data was evaluated by Langmuir, Freundlich, and Temkin isotherm models, and the outcomes revealed conformity with the Langmuir isotherm model. The Cr (VI) adsorption utilizing Fe-NPs adhered to a pseudo-first-order kinetic model. Eventually, thermodynamic studies demonstrated that the adsorption of Cr (VI) onto the surface of the Fe-NPs is endothermic and spontaneous.

Deciphering the corrosion puzzle: Nano-iron-biochar composite – Not a quick fix for metal immobilization in peat soils

The use of zero-valent iron nanoparticles in the remediation of metal-contaminated soils has received considerable attention. Upon introduction into the soil, zero-valent iron particles corrode into iron oxides, known for their high adsorption capacity for potentially toxic metals. While limited research has directly compared zero-valent iron micro- and nanoparticles, it is important to investigate whether particle size contributes to effective soil remediation. This study focuses on elucidating the comparative kinetics of iron corrosion using iron powder and a nano-iron-biochar composite. In a model experiment, these materials were exposed to a cellulose/biochar mixture and peat for five months. Mössbauer spectroscopy, X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy, and transmission electron microscopy with electron diffraction were used to analyze the corrosion products. The results show a slow corrosion rate in the nano-iron-biochar composite in cellulose due to the protective effect of biochar on the embedded iron nanoparticles. In addition, iron corrosion in peat was inhibited, likely due to the presence of humic substances. Transmission electron microscopy after five months of corrosion revealed round metal particles encased in a graphite capsule with visible channels. Large dissolved organic matter molecules in the peat likely block these channels, inhibiting metallic iron corrosion. Consequently, the nano-iron-biochar composite emerges as a slow-reacting option for immobilizing soil metals in peat. This study highlights the need for further research involving long-term field experiments.

Single step synthesis of sulfidated nanoscale iron modified kaolin clay for hexavalent chromium remediation from groundwater

Single step synthesis of sulfidated nanoscale iron modified kaolin clay for hexavalent chromium remediation from groundwater

Nonmagnetic framboid and associated iron nanoparticles with a space-weathered feature from asteroid Ryugu

Extraterrestrial minerals on the surface of airless Solar System bodies undergo gradual alteration processes known as space weathering over long periods of time. The signatures of space weathering help us understand the phenomena occurring in the Solar System. However, meteorites rarely retain the signatures, making it impossible to study the space weathering processes precisely. Here, we examine samples retrieved from the asteroid Ryugu by the Hayabusa2 spacecraft and discover the presence of nonmagnetic framboids through electron holography measurements that can visualize magnetic flux. Magnetite particles, which normally provide a record of the nebular magnetic field, have lost their magnetic properties by reduction via a high-velocity (>5 km s–1) impact of a micrometeoroid with a diameter ranging from 2 to 20 μm after destruction of the parent body of Ryugu. Around these particles, thousands of metallic-iron nanoparticles with a vortex magnetic domain structure, which could have recorded a magnetic field in the impact event, are found. Through measuring the remanent magnetization of the iron nanoparticles, future studies are expected to elucidate the nature of the nebular/interplanetary magnetic fields after the termination of aqueous alteration in an asteroid.

Iron-Based Nanoparticles Synthesis, Characterization, and Antimicrobial Effectiveness

Background: Antimicrobial resistance (AMR) has emerged as a significant and pressing public health concern, posing serious challenges to effectively preventing and treating persistent diseases. Developing new antibiotics with different mechanisms of action is crucial to effectively address challenges in treating infections. A lot of work has already been done on mono-metallic nanoparticles to address the issue.Methods: This study aimed to synthesize multi-metallic iron, silver, and chitosan-embedded nanoparticles using a green approach. Iron, silver, chitosan nanoparticles, and a composite of iron–silver–chitosan was also synthesized. The synthesized nanoparticles and composites were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier Transform Infrared Spectroscopy (FTIR) to evaluate their structural parameters. Their antimicrobial efficacy was investigated through MIC (minimum inhibitory concentration), MBC (minimum bactericidal concentration), and well-disk diffusion assays against Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Staphylococcus epidermidis and Candida albicans.Results: The size of the Cu-NPs, Cu-Ag NPs, and Cu-Ag-CS NPs were found to be in the range of 32-40 nm size with a spherical shape. The nanocomposites' MIC and MBC were calculated to be 125 μg/mL and 500 μg/mL, respectively. The nanocomposites exhibited a range of clear inhibition zones, with a minimum diameter of 12 ± 0.5 mm and a maximum diameter of 22 ± 0.5 mm. Conclusion: The iron–silver–chitosan nanocomposite has been shown to have significant antimicrobial effects in the laboratory environment compared to other nanoparticles hence can be applied as potential biomedical/biological candidates in future.Keywords: Antibacterial; Antifungal Agents; Iron; Silver; Chitosan; Nanoparticles

Fabrication of iron nanoparticles using different bioactive precursors, their characterization and bioactivity evaluation

This study deals with the green synthesis of Iron nanoparticles (FeNPs) using plant extracts of Polygonum plebeium (Knotweed) and Camellia sinensis (Green tea), focusing on their antibacterial potential, biocatalytic action as well as prospective applications as nanofertilizers. Plant materials underwent a thorough cleaning and were processed into aqueous extracts. The synthesis of FeNPs involved blending these extracts with ferric chloride solution, resulting in a versatile nanomaterial that was subjected to various characterization techniques, such as UV-Vis spectroscopy, FT-IR, XRD, SEM, and DLS-Zeta unveiling critical nanoparticle attributes of the synthesized nanoparticles, including the size, crystallinity, morphology, stability, and elemental composition. The synthesized FeNPs exhibited substantial antibacterial activities, against Escherichia coli and Staphylococcus aureus. Additionally, the biocatalytic properties of the synthesized FeNPs were investigated through dye degradation. These nanoparticles further, were demonstrated for their potential as nanofertilizers, enhancing the germination and growth of tomato and radish seeds. The merging of nanotechnology and plant-based synthesis represents a promising intersection with the capacity to revolutionize diverse fields.

Efficient and low-cost mesoporous magnetic carbon composites derived from date palm stones for environmental remediation of hexavalent chromium

AbstractThis study was performed to achieve two important scientifically challenging goals, environmental remediation of toxic heavy metals and utilization of agricultural lignocellulosic wastes. In this work, a series of mesoporous magnetic carbon (MMC) adsorbents were synthesized by carbothermic reduction at different temperatures employing date palm (Phoenix dactylifera L.) stones as the carbon source. The synthesized adsorbents were characterized by different technquies and the results confirmed the presence of zero-valent iron (ZVI) nanoparticles and other iron oxides as products of the carbothermal reduction. The nature of phases present, crystallite size and the surface properties were found to be dependent on the calcination temperature. The adsorbent MMC700 exhibited the smallest (ZVI) crystallite size 36 nm and the largest SBET 341 m2/g. All adsorbents showed mesoporous structure with mesopore average diameter lower than 6 nm. The performance was evaluated in the removal process of toxic Cr(VI) in an aqueous medium, and the optimum conditions of the process were reported. The removal process was dependant of solution pH where best results was achieved at pH = 2. Complete removal of chromium was achieved in less than 5 min by MMC700. The results were better fitted with pseudo-second-order kinetics and followed the Freundlich model isotherm. The maximum adsorption capacity was found to be 265.25 mg/g for MMC700, suggesting its application as an efficient, low-cost, and easily separable adsorbent for the toxic Cr(VI) removal process. The prepared adsorbents exhibited superior performance in the removal process compared to other agricultural wastes or biomass - derived adsorbents reported in literature.

Blackening failure of poly-α-olefin impregnated porous polymide due to the splitting of lubrication oil catalyzed by iron

AbstractLubrication failure accompanying with blackening phenomenon significantly reduces the long-running operational reliability of porous polymide (PPI) lubricated with poly-α-olefin (PAO) oil. Here, the effects of lubrication condition and counter-surface chemistry on the blackening failure of PAO impregnated PPI were studied through the comparison of the tribological tests against GCr15 steel ball and Al2O3 ceramic ball with and without PAO oil lubrication. Black products were found to be formed on the PAO impregnated PPI surface slid against steel ball or Al2O3 ball added with iron nano-particles, but be absent under the conditions without iron or PAO oil. Further analysis indicated that the iron-catalyzed splitting of PAO oil into small molecule alkanes and following the formation of black organic matter should be mainly responsible for the blackening phenomenon. Molecular dynamic (MD) simulations demonstrated that the iron facilitated the separation of hydrogen atom and the following broken of C-C bonds in PAO molecules, final resulting in the splitting of PAO oil.

Equilibrium and kinetic modeling of Cr(VI) removal by novel tolerant bacteria species along with zero-valent iron nanoparticles

This work describes the study of the removal of a refractory contaminant, i.e., Hexavalent chromium (Cr(VI)) from aqueous systems by a novel adsorbent comprising Cr(VI) tolerant bacteria and zero valent iron nanoparticle (nZVI). A gram-positive, rod-shaped bacteria used in the study were isolated from wastewater (WW) received from the effluent of leather industries. The adsorbents were prepared with bacteria, nZVI alone, and a combination of both. The adsorbent comprising both elements was found to remove Cr(VI) with a higher percentage (93%) and higher capacities (0.58 mg/g) as compared to adsorbent with bacteria (Cr(VI) removal = 63%, qe = 0.163 mg/g) or nanoparticles (Cr(VI) removal = 80%, qe = 0.45 mg/g) alone. The adsorbent worked best at neutral pH, and the removal became saturated after 90 min of incubation. Equilibrium studies with isotherm modeling suggested that the adsorption process follows sips isotherm (R2 = 0.9955), which is expected to bean intra-particle diffusion process before the actual adsorption. Process kinetics was modeled with pseudo-first order, pseudo-second order, and Vermeulen model. The diffusion coefficient determined by fitting the kinetic data to Vermeulen model was found to be 0.0000314 cm2/s. The adsorbent can be tested further for continuous flow processes to find more insights about the usage on a large scale.

Targeted Drug Delivery through the Synthesis of Magnetite Nanoparticle by Co-Precipitation Method and Creating a Silica Coating on it

Billions of dollars are spent annually in the world to treat and investigate problems caused by drug side effects. According to the estimation of health researchers, a huge part of people who take medicine suffer from complications caused by it. In this way, the necessity of using a targeted system in order to deliver medicine to the targeted place without damaging healthy tissues is felt more than before. In recent years, targeted drug delivery systems based on nanoparticles have received much attention. In the same direction, in this research, co-precipitation method was used to prepare magnetic nanoparticles using iron(|) and iron(||) oxides, and further, according to the synthesis steps of magnetite nanoparticles (MNPs) and the mechanism of formation and identification of magnetite nanoparticles ( Fe3O4) by examining the infrared pattern (FT-IR) obtained from Fe3O4 nanoparticles, the results of the magnetometric test (VSM) of Fe3O4 nanoparticles, X-ray diffraction pattern (XRD) of Fe3O4 nanoparticles, Field Emission Scanning Electron Microscope (FE-SEM) images obtained from Fe3O4 nanoparticles was discussed. After this stage, silica- coated iron nanoparticles (Fe3O4@SiO2) were prepared, and the infrared (FT-IR) pattern of Fe3O4@SiO2) was also investigated. It is worth mentioning that the mechanism of formation and identification of magnetic silica-coated iron nanoparticles (Fe3O4@SiO2) has been described in detail. Therefore, the obtained results indicate that the drug can be guided in a controlled and targeted manner by the magnetic field, and the results of the FE-SEM images show that the obtained product has a spherical morphology and the particle size distribution was less than 100 nm. Therefore, spherical shape and the symmetry of these particles can be helpful for their movement in the liquid mediu.

Biosynthesis Optimization of Antibacterial-Magnetic Iron Oxide Nanoparticles from Bacillus megaterium.

The occurrence of antibiotic resistance on common bacterial agents and the need to use new generations of antibiotics have led to the use of various strategies for production. Taking inspiration from nature, using bio-imitation patterns, in addition to the low cost of production, is advantageous and highly accurate. In this research, we were able to control the temperature, shake, and synthesis time of the synthesis conditions of Bacillus megaterium bacteria as a model for the synthesis of magnetic iron nanoparticles and optimize the ratio of reducing salt to bacterial regenerating agents as well as the concentration of salt to create iron oxide nanoparticles with more favorable properties and produced with more antibacterial properties. Bacterial growth was investigated by changing the incubation times of pre-culture and overnight culture in the range of the logarithmic phase. The synthesis time, salt ratio, and concentration were optimized to achieve the size, charge, colloidal stability, and magnetic and antibacterial properties of nanoparticles. The amount of the effective substance produced by the bacteria was selected by measuring the amount of the active substance synthesized using the free radical reduction (DPPH) method. With the help of DPPH, the duration of the synthesis was determined to be one week. Characterizations such as UV-vis spectroscopy, FTIR, FESEM, X-ray, and scattering optical dynamics were performed and showed that the nanoparticles synthesized with a salt concentration of 80mM and a bacterial suspension to salt ratio of 2:1 are smaller in size and have a light scattering index, a PDI index close to 0.1, and a greater amount of reducing salt used in the reaction during one week compared to other samples. Moreover, they had more antibacterial properties than the concentration of 100mM. As a result, better characteristics and more antibacterial properties than common antibiotics were created on E. coli and Bacillus cereus.