Fe3O4 NPs Research Articles

Iron oxide nanoparticle (Fe3O4 NPs) synthesized from B. subtilis reduced arsenic (as) toxicity in rice (Oryza sativa L.) plant

Arsenic (As) is one of the most important water pollutant of global concern due to its extreme hazard. In the present study, B. subtilis synthesized iron oxide nanoparticles (Fe3O4 NPs) were used for mitigation of harmful metalloid As from the aqueous solution. Initially, the arsenic removal efficiency was tested in a batch culture experiment across various concentrations (5, 10 and 15 ppm) of B. subtilis synthesized Fe3O4 NPs at different pH, time interval and agitation speed. Optimal removal efficiency of As by using B. subtilis synthesized Fe3O4 NPs was observed at pH 7, after 80 min, and with agitation at 200 rpm. Additionally, hydroponic culture experiment was designed to assess B. subtilis synthesized Fe3O4 NPs efficiency in removal of As from As-contaminated water used to irrigate rice plants. Results revealed that B. subtilis synthesized Fe3O4 NPs effectively removed As from the contiminated water and reduced its uptake by the different parts of rice plants (root, shoot and leaf). Furthermore, these B. subtilis synthesized Fe3O4 NPs also reduced the bioaccumulation and enhanced plant tolerance to As, suggesting their potential in mitigating heavy metal toxicity, especially As and promoting plant growth. Thus, this study proposes B. subtilis synthesized Fe3O4 NPs as nano-adsorbents in reducing arsenic toxicity in rice plants.

Green synthesis of Abutilon indicum (L) derived iron oxide (FeO) nanoparticles with excellent biological, anticancer and photocatalytic activities

Cancer is one of the most common causes of death all over the world. Although there are many treatments available none of them are without side-effect and most of them are very expensive. Similarly, Inflammation is one of another common medical condition worldwide but most of the therapies available are not environment and pocket friendly. Thus, the aim of our study was to synthesize environmentally friendly, cost-effective FeO NPs with significant anticancer, anti-inflammatory, antibacterial properties. The green synthesis of Iron Oxide Nanoparticles (FeO NPs) using plant extract is one of the environmentally friendly, cost-effective, and a secure alternative to physical or chemical synthesis methods. In the present study we used Abutilon indicum leaf extract to synthesize the Ai-FeO NPs and performed various experiments to confirm the therapeutic potential of green synthesized Ai-FeO nanoparticles. In this method, an aqueous plant leaf extract (A. indicum: Ai) was used as a reducing and stabilizing agent for the synthesis of FeO nanoparticles. The synthesized Ai-FeO NPs were characterized by the ultraviolet–visible (UV–Vis) absorbance of the surface at a resonance band 415 nm. Fourier transform infrared (FTIR) spectroscopy study confirmed the inherent bioactive functional groups as capping and stabilizing agents for Ai-FeO NPs. The X-ray powder diffraction (XRD) spectra revealed crystalline nature of the NPs. Further, the synthesized NPs have been isolated in highly stable, crystalline nature with spherical shape having size 10–95 nm. In addition, the green synthesized Ai-FeO-NPs demonstrated dose-dependent antimicrobial, antioxidant, anti-inflammatory, and anticancer properties. The findings of this study suggested that A. indicum leaf extract mediated FeO nanoparticles could be potentially used as a therapeutic agent for many human diseases and breast cancer.

Green synthesis of FeO nanoparticles from coffee and its application for antibacterial, antifungal, and anti-oxidation activity

Abstract This study presents a sustainable method for producing iron oxide nanoparticles (FeO NPs) using aqueous extracts from coffee seeds. Characterization through X-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy (TEM) revealed non-spherical NPs ranging from 30 to 50 nm. The XRD analysis confirmed that the face-centred cubic structure and the Debye–Scherrer’s crystalline size support the FeO particle size confirmed from TEM. The synthesized NPs demonstrated significant antimicrobial activity against Escherichia coli and Staphylococcus aureus, as well as antifungal activity against Aspergillus niger. Additionally, they exhibited potent antioxidant properties, effectively inhibiting DPPH, α-amylase, and α-glucosidase compared to acarbose and coffee extract. The findings suggest that these FeO NPs hold promise as antimicrobial, antioxidant, antifungal, and potentially antidiabetic agents.

Selective Separation of Rare Earth Ions from Mine Wastewater Using Synthetic Hematite Nanoparticles from Natural Pyrite

The separation of rare earth ions (RE3+) from aqueous solutions poses a significant challenge due to their similar chemical and physical characteristics. This study presents a method for synthesizing hematite nanoparticles (Fe2O3 NPs) through the high-temperature phase transition of natural pyrite for adsorbing RE3+ from mine wastewater. The characteristics of Fe2O3 NPs were studied using XRD, SEM, BET, XPS, FTIR, and Zeta potential. The optimal condition for RE3+ adsorption by Fe2O3 NPs was determined to be at pH 6.0 with an adsorption time of 60 min. The maximum adsorption capacities of Fe2O3 NPs for La3+, Ce3+, Pr3+, Nd3+, Sm3+, Gd3+, Dy3+, and Y3+ were 12.80, 14.02, 14.67, 15.52, 17.66, 19.16, 19.94, and 11.82 mg·g−1, respectively. The experimental data fitted well with the Langmuir isotherm and pseudo-second-order models, suggesting that the adsorption process was dominated by monolayer chemisorption. Thermodynamic analysis revealed the endothermic nature of the adsorption process. At room temperature, the adsorption of RE3+ in most cases (La3+, Ce3+, Pr3+, Nd3+, Sm3+, and Y3+) onto Fe2O3 NPs was non-spontaneous, except for the adsorption of Gd3+ and Dy3+, which was spontaneous. The higher separation selectivity of Fe2O3 NPs for Gd3+ and Dy3+ was confirmed by the separation factor. Moreover, Fe2O3 NPs exhibited excellent stability, with an RE3+ removal efficiency exceeding 94.70% after five adsorption–desorption cycles, demonstrating its potential for the recovery of RE3+ from mine wastewater.

Photocatalytic degradation of biological contaminant (E. coli) in drinking water under direct natural sunlight irradiation using incorporation of green synthesized TiO2, Fe2O3 nanoparticles

AbstractGlobally, there is a severe problem of widespread water contamination. Adsorption and photocatalytic degradation are considered the most suitable methods for removing these water pollutants because of their simplicity, environmental friendliness, and capacity to generate high-quality water. By a completely green route, in this recent study, the fungus Aspergillus tubingensis was able to synthesize TiO2 and Fe2O3 NPs with an average diameter of 28.0 and 65 nm, respectively. The smallest NPs diameters were produced when the precursor salt concentrations were 10−3 M and 10−2 M for TiO2 and Fe2O3, respectively, at pH 3 and an incubation time of 72 h. The biosynthesized NPs were characterized using DLS, TEM, EDX, and VSM. They were then applied in the preparation of titanium-iron nanocomposites with different ratios (1:1, 1:2, and 2:1 (w/w)) and characterized by FTIR and XRD. In this study, Escherichia coli (E. coli) was photo-catalytically inactivated using a TiO2–Fe2O3 nanocomposite as a photocatalyst in the presence of direct sunlight. This material’s photocatalytic performance was evaluated in comparison to that of TiO2 and Fe2O3 NPs. After 60 min of exposure to direct sunlight, the cell death was estimated as 97.97%, 99.32%, 89.06%, 30.96%, and 25.14% in the presence of TF-1, TF-2, TF-3, TiO2, and Fe2O3, respectively. Under direct natural sunlight irradiation for 60 min, TiO2 and Fe2O3 nanoparticles alone have the least impact on E. coli, whereas TF-2 nanocomposite has a higher level of photocatalytic bacterial inactivation competency than TF-1 and TF-3 nanocomposites. No significant toxicity has been observed for TF-2-treated water samples in the toxicity assessment.

Facile one step microwave assisted biofabrication of Fe2O3 NPs: potential application as solar light-driven photocatalyst in the photodegradation of acridine orange

ABSTRACT The utilisation of a recently developed green approach for synthesising iron oxide nanoparticles (Fe2O3NPs) is highly promising, given its low toxicity and environmentally benevolent attributes. In this investigation, Fe2O3 NPs were produced through the utilisation of ferric chloride hexahydrate, incorporating Permelia perleta ;(lichen) extract under standard atmospheric conditions. The development of Fe2O3 NPs was verified through a systematic characterization process by employing UV FTIR, XRD, and FE SEM studies. The average crystallite size of the developed sample was found to be 20 nm determined by using Debye – Scherrer equation. The efficacy of the developed Fe2O3 NPs as a photocatalyst in eliminating acridine orange was evaluated, highlighting key factors such as catalyst dosage, initial dye concentration, and pH. Augmenting the quantity of Fe2O3 NPs amplified the decolourisation of the dyes, reaching a peak of 70% dye degradation at pH 2 after 2 h with a catalyst dose of 0.9 g/L. The most pronounced effect was observed against Bacillus subtilis (22 mm), whereas the least impact was noted for Pseudomonas aeruginosa (14 mm). Furthermore, the developed nanoparticles underwent antioxidant activity analysis, revealing that 1 gm of nanoparticles possesses antioxidant activity equivalent to 4.22 mg of ascorbic acid.

Three-dimensional polymer phenylethnylcopper/nitrogen doped graphene aerogel electrode coupled with Fe3O4 NPs nanozyme: Toward sensitive and robust photoelectrochemical detection of glyphosate in agricultural matrix

BackgroundPresently, glyphosate (Gly) is the most extensively used herbicide globally, Nevertheless, its excessive usage has increased its accumulation in off-target locations, and aroused concerns for food and environmental safety. Commonly used detection methods, such as high-performance liquid chromatography and gas chromatography, have limitations due to expensive instruments, complex pre-processing steps, and inadequate sensitivity. Therefore, a facile, sensitive, and reliable Gly detection method should be developed. ResultsA photoelectrochemical (PEC) sensor consisting of a three-dimensional polymer phenylethnylcopper/nitrogen-doped graphene aerogel (PPhECu/3DNGA) electrode coupled with Fe3O4 NPs nanozyme was constructed for sensitive detection of Gly. The microscopic 3D network of electrodes offered fast transfer routes for photo-generated electrons and a large surface area for nanozyme loading, allowing high signal output and analytical sensitivity. Furthermore, the use of peroxidase-mimicking Fe3O4 NPs instead of natural enzyme improved the stability of the sensor against ambient temperature changes. Based on the inhibitory effect of Gly on the catalytic activity Fe3O4 NPs, the protocol achieved Gly detection in the range of 5 × 10−10 to 1 × 10−4 mol L−1. Additionally, feasibility of the detection was confirmed in real agricultural matrix including tea, maize seedlings, maize seeds and soil. SignificanceThis work achieved facile, sensitive and reliable analysis towards Gly, and it was expected to inspire the design and utilization of 3D architectures in monitoring agricultural chemicals in food and environmental matrix.

Diethyldithiocarbamate-ferrous oxide nanoparticles inhibit human and mouse glioblastoma stemness: aldehyde dehydrogenase 1A1 suppression and ferroptosis induction.

The development of effective therapy for eradicating glioblastoma stem cells remains a major challenge due to their aggressive growth, chemoresistance and radioresistance which are mainly conferred by aldehyde dehydrogenase (ALDH)1A1. The latter is the main stemness mediator via enhancing signaling pathways of Wnt/β-catenin, phosphatidylinositol 3-kinase/AKT, and hypoxia. Furthermore, ALDH1A1 mediates therapeutic resistance by inactivating drugs, stimulating the expression of drug efflux transporters, and detoxifying reactive radical species, thereby apoptosis arresting. Recent reports disclosed the potent and broad-spectrum anticancer activities of the unique nanocomplexes of diethyldithiocarbamate (DE, ALDH1A1 inhibitor) with ferrous oxide nanoparticles (FeO NPs) mainly conferred by inducing lipid peroxidation-dependent non-apoptotic pathways (iron accumulation-triggered ferroptosis), was reported. Accordingly, the anti-stemness activity of nanocomplexes (DE-FeO NPs) was investigated against human and mouse glioma stem cells (GSCs) and radioresistant GSCs (GSCs-RR). DE-FeO NPs exhibited the strongest growth inhibition effect on the treated human GSCs (MGG18 and JX39P), mouse GSCs (GS and PDGF-GSC) and their radioresistant cells (IC50 ≤ 70 and 161μg/mL, respectively). DE-FeO NPs also revealed a higher inhibitory impact than standard chemotherapy (temozolomide, TMZ) on self-renewal, cancer repopulation, chemoresistance, and radioresistance potentials. Besides, DE-FeO NPs surpassed TMZ regarding the effect on relative expression of all studied stemness genes, as well as relative p-AKT/AKT ratio in the treated MGG18, GS and their radioresistant (MGG18-RR and GS-RR). This potent anti-stemness influence is primarily attributed to ALDH1A1 inhibition and ferroptosis induction, as confirmed by significant elevation of cellular reactive oxygen species and lipid peroxidation with significant depletion of glutathione and glutathione peroxidase 4. DE-FeO NPs recorded the optimal LogP value for crossing the blood brain barrier. This in vitro novel study declared the potency of DE-FeO NPs for collapsing GSCs and GSCs-RR with improving their sensitivity to chemotherapy and radiotherapy, indicating that DE-FeO NPs may be a promising remedy for GBM. Glioma animal models will be needed for in-depth studies on its safe effectiveness.

Innovative electrochemical sensor based on Fe3O4@Fe-BTC nanocomposite to sensitive determination of 4-nitrophenol

The Fe3O4@Fe-BTC nanocomposite has been thoroughly investigated in this study. The synthesis of Fe-BTC framework has involved a solvothermal method, while Fe3O4 NPs have been prepared using a coprecipitation technique. The resulting materials have been characterized using various techniques (XRD, FT-IR spectra, and SEM images). The electrochemical behaviors have been analyzed using CV and EIS. More interestingly, the electrochemical performance of 4-nitrophenol (4-NP) has also been investigated on the various modified electrodes via CV, DPV, and CA measurements in a 0.1 M PBS buffer by studying the electrochemical reduction of 4-NP. Remarkably, the Fe3O4@Fe-BTC nanocomposites have exhibited enhanced electrochemical properties when compared with the individual Fe3O4 and Fe-BTC components. This improvement could be attributed to the synergistic effects of the highly porous Fe-BTC and the magnetic Fe3O4 NPs, leading to enhanced electron transfer kinetics and electrocatalytic activity. These findings underscore the potential of designed nanocomposite materials for various electrochemical applications.

Development of a magnetite nanocomposite based on expanded graphite/chitosan for efficient removal of brilliant green dye from aqueous solutions

ABSTRACT In this research, to develop an efficient and magnetic graphite-based nanocomposite (Fe3O4/EG-chitosan), the natural flake graphite was first expanded to improve its active surface area. The expanded graphite (EG) was then functionalized and magnetized with chitosan and Fe3O4 nanoparticles to increase its adsorption performance. Structure of EG/chitosan and nanocomposite Fe3O4/EG-chitosan were determined and confirmed by FT-IR, XRD, EDX, FESEM, VSM, zeta potential measurement and BET surface area measurements. The surface area of EG was improved from 10.13 to 83.08 m2/g after the functionalization of it using chitosan. Fe3O4/EG-chitosan exhibited a lower magnetization saturation value (30.9 emu/g) in compared with pure Fe3O4 NPs (60.2 emu/g). The fabricated nanocomposite was then applied to adsorb BG dye from aqueous media. The optimal removal of 98% BG dye was achieved at pH 8.0, adsorbent dosage 0.04 g, initial concentration 50 ppm, and temperature 293 K. The adsorption of BG is described well with the pseudo-second order kinetic model and the Freundlich isotherm model. The results also showed that the maximum adsorption capacity of BG dye was 21.8 mg/g using the Langmuir isotherm model. In addition, after 6 adsorption-desorption cycles, the adsorption capacity of the developed Fe3O4/EXG-chitosan toward BG remains high (90%).

The utility of Hibiscus sabdariffa L. to prepare metal oxides NPs for clinical application on osteoporosis supported by theoretical study.

Green synthesis of metal oxides as a treatment for bone diseases is still exploring. Herein, MgO and Fe2O3 NPs were prepared from the extract of Hibiscus sabdariffa L. to study their effect on vit D3, Ca+2, and alkaline phosphatase enzyme ALP associated with osteoporosis. Computational chemistry was utilized to gain insight into the possible interactions. These oxides were characterized by X-ray diffraction, SEM, FTIR, and AFM. Results revealed that green synthesis ofMgO and Fe2O3 NPs was successful with abundant. MgO NPs were in vitro applied onosteoporosis patients (n=35) and showed a significant elevation of vit D3 and Ca+2 (0.0001>p<0.001) levels, compared to healthy volunteers (n=25). Thus, Hibiscus sabdariffa L. is a good candidate to prepare MgO NPs, with a promising enhancing effect on vit D3 and Ca+2 in osteoporosis. In addition, interactions of Fe2O3 and MgO NPs with ALP were determined by molecular docking study.

Bio fabrication of Fe2O3 NPs and their analgesia efficiency for post-operative epidural anaesthetic applications- study of chronic inflammatory pain model in mice

ABSTRACT The current study reported the synthesis of ferric oxide nanoparticles (Fe2O3 NPs) using the leaf extract of Amaranthus spinosus Linn and studied their analgesia efficiency in chronic inflammatory pain model in mice. X-RD, TEM results showed that the spherical Fe2O3 NPs having rhombohedral crystalline structure with an average particle size of 10 nm. Additionally, inflammatory pain models were designed through FCA injection on the CD1 mice hind paw with various Fe2O3 NPs doses and analgesic behaviour was monitored. The prepared Fe2O3 NPs showed a dose-dependent analgesic activity with considerable decrease in inflammatory cells, ROS production and pro-inflammatory markers. Additionally, the expression of enzymes responsible for ROS production were decreased. The outcomes of present work revealed the local administration of Fe2O3 NPs caused the substantial analgesia through reduction of pro-inflammatory signalling and inflammatory cellular infiltration along with micro-environmental free radical scavenging in mouse inflammatory pain model.

Iron oxide nanoparticles synthesized using Mentha spicata extract and evaluation of its antibacterial, cytotoxicity and antimigratory potential on highly metastatic human breast cells

Iron oxide nanoparticles (Fe2O3 NPs) were synthesized utilizing Mentha spicata sourced from Cyprus as a stabilizing agent. The study delved into assessing the antimicrobial, cytotoxic, anti-proliferative, and anti-migratory potential of Fe2O3 NPs through disc diffusion, trypan blue, and 3-[4, 5-dimethylthiazol-2-yl]−2, 5-diphenyltetrazolium bromide (MTT) assay, respectively. Characterization of the synthesized Fe2O3 NPs was conducted using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), UV–vis spectroscopy (UV–vis), scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDX). The FTIR, XRD, and SEM-EDX spectra confirmed the successful formation of Fe2O3 NPs. The analysis of UV–vis spectra indicates an absorption peak at 302 nm, thereby confirming both the successful synthesis and remarkable stability of the nanoparticles. The nanoparticles exhibited uniform spherical morphology and contained Fe, O, and N, indicating the synthesis of Fe2O3 NPs. Additionally, the Fe2O3 NPs formed through biosynthesis demonstrated antimicrobial capabilities against Escherichia coli and Bacillus cereus. The significant anti-migratory potential on MDA-MB 231 human breast cancer cells was observed with lower concentrations of the biosynthesized Fe2O3 NPs, and higher concentrations revealed cytotoxic effects on the cells with an IC50 of 95.7 μg/ml. Stable Fe2O3 NPs were synthesized using Mentha spicata aqueous extract, and it revealed antimicrobial activity on E. coli and B. cereus, cytotoxic, anti-proliferative and anti-migratory effect on highly metastatic human breast cancer cell lines.

Using Silica Shell to Improve the Surface of Magnetite Prepared by Biosynthesis Method

The combined of superparamagnetic properties (magnetite) and surface characteristics (silica), can produce structures with multiple capacities. The preparation of such magnetite-silica core-shell nanoparticles involves high costs in their execution and longer time. In this work, Fe3O4@SiO2 CSNPs were synthesized in two stages to control their size and the possibility of adjusting their characteristics. First, Fe3O4 NPs were synthesized by a green method using carob leaf extract, then coating the magnetite nanoparticles with a silica layer was done by using Tetraethylorthosilicate (TEOS) as a silica precursor. X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscope (AFM), Fourier transform infrared, and vibrating sample magnetometer techniques were used to characterize the magnetite-silica CSNPs. TEM images confirms that Fe3O4NPS and Fe3O4@SiO2 CSNPs synthesized had a spherical shape and were within 9 and 17 nm. The average crystallite sizes of the synthesized Fe3O4 NPs and Fe3O4@SiO2CSNPs were found to be 17.8 nm and 20 nm. The VSM indicated that the magnetization decreased due to being coated with silica.

Experimental modelling of heating and local field enhancement by iron oxide nanoparticles upon laser excitation

SignificanceLocal determination of the iron oxide nanoparticles (IONPs) temperature during laser heating is important in the aspect of laser phototherapy. ApproachWe have carried out theoretical modeling of local EM field enhancement and heating under the laser action near individual IONPs and ensembles of NPs with different sizes of the magnetic core and different content of iron oxide in them. To experimental determine the temperature of IONPs water colloids, we used fluorescence thermometry based on rhodamine B (RhB) fluorescence lifetime. ResultsLocal EM field enhancement and heating strongly depend on the NPs shape and distance between them. In the case of anisotropic NPs, a significant change in the spatial distribution of the EM field near the NPs surface was observed. The local heating of NPs in an ensemble reaches sufficiently higher values, the relative change was about 35°С for Fe2O3 NPs. Nevertheless, all the studied IONPs water colloids showed heating by no more than 15°C. ConclusionsSignificant enhancement of the local field occurs in IONP pairs and ensembles. The heating temperature of the ensemble depends on the thermal conductivity of the medium, in which the heat dissipation depends.

Evaluation of Antibacterial, Antioxidant and Immunomodulatory Potential of Mitragyna parvifolia Leaves-Assisted Fe2O3 Nanoparticles

This work includes the use of leaves of Mitragyna parvifolia for green synthesis of [Formula: see text] nanoparticles ([Formula: see text] NPs), which offers a sustainable eco-friendly approach. Characterization of synthesized [Formula: see text] NPs was done by UV-visible, FTIR spectroscopy, XRD and FESEM studies. FTIR exhibited the existence of Fe-O, O–H and COO–Fe stretching owing to the occurrence of the carboxylic group. FESEM analysis revealed that the average size of [Formula: see text] NPs was 92 nm, which varies in their shape. The study also includes the determination of antibacterial, in vitro antioxidant and immunomodulatory efficacy of synthesized [Formula: see text] NPs. Results suggested that [Formula: see text] NPs exhibit potent antibacterial efficacy against B. subtilis and S. aureus, gram-positive as well as E. coli and P. aureginosa, gram-negative bacterial strains used in this study. The study exhibited significant ([Formula: see text] &lt; 0.01) in vitro antioxidant and immunomodulatory potential of synthesized [Formula: see text] NPs against concanavalin-A activated Wistar albino rat’s splenocytes. The green synthesized [Formula: see text] NPs using M. parvifolia leaves may offer a novel approach in the medicinal and immunological field to overcome oxidative stress as well as enhance immune responses for potential health benefits of human beings.

Magnetite/MXene (Fe3O4/Ti3C2) Nanocomposite as a Novel Adsorbent for Environmental Remediation of Malachite Green Dye.

In this work, a novel adsorbent called magnetite/MXene (Fe3O4/Ti3C2) nanocomposite was prepared, characterized, and applied for the removal of organic dye, malachite green dye (MG), from both real water and model solutions. Numerous techniques were used to characterize the prepared Fe3O4/Ti3C2 nanocomposite: XRD, SEM, TEM, FTIR, and surface area analysis. The outcomes showed that the Al layer had been selectively etched, that the MAX phase (Ti3AlC2) had been transformed into layered Ti3C2 MXene, that the cubic Fe3O4 phase had been prepared, and that the prepared Fe3O4 NPs had been evenly distributed on the MXene surface. Also, SEM pictures showed the successful etching of the MAX phase and the formation of the ultrathin multi-layered MXene, which the Fe3O4 NPs covered upon forming the Fe3O4/Ti3C2 nanocomposite at the surface and inside the ultrathin multi-layered MXene. The effect of different operational parameters affecting the removal process was explored and optimized. The MG dye was removed mostly within 60 min, with a 4.68 mg/g removal capacity using 5 mg of the Fe3O4/Ti3C2 nanocomposite. The removal was examined from both kinetic and thermodynamic perspectives, and the findings demonstrated the spontaneity of the removal process as well as the applicability of fractal-like pseudo-first-order and fractal-like pseudo-second-order kinetics when compared to other kinetics models. The Fe3O4/Ti3C2 nanocomposite was used to remove MG dye from real spiked environmental water samples, and the results revealed the successful remediation of the real samples from the organic dye by the Fe3O4/Ti3C2 nanocomposite. Accordingly, Fe3O4/Ti3C2 nanocomposite could be considered a potential adsorbent for the environmental remediation of polluted water.

Highly selective and sensitive humidity sensor using reduced graphene oxide based iron oxide nanocomposites

For the humidity sensing, rGO/Fe2O3 nanocomposites were synthesized via an ultrasonic-assisted method, utilizing Hummers' and co-precipitation techniques for rGO and Fe2O3 synthesis. XRD analysis confirmed the formation of rGO and rhombohedral Fe2O3 NPs, while SEM revealed varied (rough sheet-like and dense compact) morphologies. UV–VIS spectra indicated characteristic absorption peaks for rGO, Fe2O3 NPs, and their NCs. In addition, FTIR spectra validated graphene oxide reduction and Fe2O3 NPs/NCs formation. Humidity sensing was assessed across 40–80 % RH at varying frequencies (100 Hz-10 kHz), with 100 Hz identified as the optimal frequency due to water molecule polarization limitations at higher frequencies. The rGO/Fe2O3 (70/30) NC exhibited a rapid response recovery time (5 s/10 s) and high sensitivity (2715.541 %), attributed to additional active sites provided by Fe2O3, enhancing water molecule adsorption and sensor sensitivity. The sensors demonstrated long-term stability and repeatability, showcasing promising potential for humidity sensing applications.

Effect of reaction and post-treatment conditions on physico-chemical properties of magnetic iron oxide nano-particles

Poor stability and dispersibility, as well as aggregation are considered as major challenges in clinical application of iron oxide nanoparticles (IONPs). Several studies have shown that the synthesis parameters and post-synthesis treatments e.g., drying methods, have the capability to improve the particles' characteristics. Herein, we investigate the combined effect of synthesis and post-treatment parameters on the particle size, stability and magnetism of IONPs. Magnetite (Fe3O4) NPs were prepared via co-precipitation and post-treated using different methods, i.e. (i) freeze dried at –53 °C, 0.133 mbar for 48 h (liquid nitrogen frozen (LFD) and freezer frozen (FFD)), (ii) vacuum oven dried (VOD) at 60 °C for 24 h, and (iii) kept wet colloidal (WET), dispersed in deionized water. The Fe3O4 NPs’ chemical functional groups, size, shape, crystallinity, stability, aggregation, porosity, and magnetic properties were further analysed using different characterisation techniques. Analytical results showed that, while the WET sample had the best stability and significantly less aggregation at different temperatures, amongst post-treated Fe3O4 NPs, LFD sample exhibited the best stability (up to 37 °C), dispersion and smallest polydispersity index. Furthermore, all dried NPs had superparamagnetic characteristics, while, LFD Fe3O4 NPs had better magnetic properties and stability than other drying methods.

Antibacterial and Antibiofilm Activity of Eucalyptus camaldulensis Derived Fe3O4 Nano-particles against Foodborne Pathogens

Foodborne pathogens are zoonotic and multidrug resistant, which are not only affecting economy but also accountable for public health burdens. The present study was aimed to evaluate the efficacy of medicinal plant i.e., Eucalyptus camaldulensis extract mediated Fe3O4 and ZnO nanoparticles against the 27 foodborne pathogenic strains, isolated from milk, meat, dry fruits and vegetable samples collected from Multan, Pakistan. In phytochemical screening, the plant extract was found to contain numerous bioactive compounds including flavonoids, phenolic compounds, tannins, quinones, and anthocyanins. Fe3O4 NPs synthesized from Eucalyptus camaldulensis displayed the highest antibacterial activity with zones of inhibition of 12-13mm against pathogens. Fe3O4 NPs were found to have highest anti-inflammatory potential with recorded percentage of 67% at 40 μg/ml. Fe3O4 NPs also demonstrated the highest antibiofilm activity after 120 hours of incubation. For DDPH antioxidant assay, the highest antioxidant activity was displayed by Fe3O4 NPs and their absorbance recorded was 1.43. Therefore, Eucalyptus camaldulensis mediated Fe3O4 NPs proved as an effective and eco-friendly approach to combat multidrug resistance in bacterial infections throughcharacteristic antibacterial, antibiofilm and antioxidant properties.