Fe3O4 Nanoparticles Research Articles

Synthesis of chitosan/Fe2O3/CuO-nanocomposite and their role as inhibitor for some biological disorders in vitro with molecular docking interactions studies

The hybrid material between the functional elements particularly with the polymer compounds as a nanocomposites are attractive in numerous fields. In the current work, chitosan/Fe2O3/CuO-nanocomposite has been successfully synthesized in situ via a coprecipitation method and characterized by several apparatuses. The X-ray diffraction cleared that chitosan/Fe2O3/CuO-nanocomposite was crystalline. Transmission Electron Microscopy (TEM) showed that the size of chitosan/Fe2O3/CuO-nanocomposite was of 17–85 nm. Candida albicans, Candida tropicalis, and Geotrichum candidum were inhibited employing the chitosan/Fe2O3/CuO-nanocomposite with inhibition areas of 25 ± 0.1 and 30 ± 0.1, and 23 ± 0.2 mm, respectively. Minimum inhibitory concentration (MIC) of chitosan/Fe2O3/CuO-nanocomposite was 15.62, 31.25, and 62.5 μg/mL for C. tropicalis, C. albicans, and G. candidum, respectively. Biofilm formation of C. albicans, C. tropicalis and G. candidum was inhibited at level of 95.31, 96.65, and 93.63 %, respectively at 75 % MIC of chitosan/Fe2O3/CuO-nanocomposite. The exposed C. tropicalis to chitosan/Fe2O3/CuO-nanocomposite showed severe damag of cytoplasm membrane with cell wall rupture. Chitosan/Fe2O3/CuO-nanocomposite reflected anticancer potential against human skin cancer (A-431) cells with IC50 of 77.79 ± 1.37 μg/mL. Moreover, wound heals was induced by chitosan/Fe2O3/CuO-nanocomposite with closure level 92.76 %. Molecular docking studies suggested strong binding of C. tropicalis (PDB ID: 8BH8) and A-431 (PDB ID: 5JJX) proteins with CuO nanoparticles and FeO nanoparticles.

Research on synthesis of imidazopyridine-sulfide-aryl derivatives: copper complex immobilized on Fe3O4 nanoparticles catalyzed one-pot C–H bond sulfenylation of imidazopyridines

This research report the development of an eco-friendly, magnetic nanocatalyst, Fe3O4@SiO2-ABHA-CuCl, for the efficient synthesis of diaryl sulfides incorporating imidazo[1,2-a]pyridine scaffolds. The catalyst was successfully prepared by immobilizing CuCl on magnetic Fe3O4 nanoparticles modified with 4-amino-3-hydroxybenzoic acid. Characterization revealed spherical nanoparticles with a size range of 15-30 nm. The catalyst exhibited excellent catalytic activity in promoting C–H bond sulfenylation of imidazopyridines using the green solvent PEG-400. Remarkably, the catalyst demonstrated exceptional recyclability over eight consecutive cycles without significant loss of activity. Comprehensive analysis confirmed the preservation of the catalyst's magnetic properties and structural integrity after repeated use.

Novel sensitive electrochemical detection of paracetamol using magnetite/MXene electrode by differential pulse voltammetry

In this research work, a novel electrochemical sensor-based Fe3O4/Ti3C2 MXene @ glassy carbon electrode (GCE) for the detection of paracetamol was prepared by simple ultrasonic method by combining Ti3C2 MXene and Fe3O4 nanoparticles. The Fe3O4/Ti3C2 MXene nanomaterial was characterized by the means of different techniques: X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM), nitrogen adsorption/desorption isotherms, as well as Fourier transform infrared spectroscopy (FTIR). The characterization results revealed the homogenous distribution of the prepared cubic Fe3O4 NPs within the prepared two-dimensional layered Ti3C2 MXene. The Fe3O4/Ti3C2 MXene @ GCE was used for the sensitive determination of the well-known analgesic drug paracetamol by differential pulse voltammetry (DPV). The prepared Fe3O4/Ti3C2 MXene @ GCE was characterized electrochemically, and the results showed that Fe3O4/Ti3C2 MXene @ GCE is a potential working electrode for the sensitive detection of paracetamol with very low detection limit (0.63 nM), within a linear dynamic range of 0.0–110.0 µM, high reproducibility and repeatability; with a very low relative standard deviation (SD%) for 7 days measurement (3.07–3.42 %), accuracy with a SD% of 0.89, high precision of 99.48 % in distilled water and 98.51 % in sea water. The proposed electroanalytical method was applied for the detection and quantification of paracetamol in real water samples, as well as different analgesic medical formulations, and the results showed outstanding accuracy and precision indicating the suitability of the Fe3O4/Ti3C2 MXene @ GCE electrode for the sensitive, accurate determination of paracetamol in diferrent matrices.

Recycling metal-organic framework residues (MOFRs) as bifunctional additives in fabricating porous ceramic membranes

In this work, Fe-MOF residues (Fe-MOFRs) were recycled and reused as a kind of bifunctional additives in the preparation of alumina ceramic membranes. To prevent the unwanted aggregation and grain growth of Fe-MOFR derived Fe2O3 nanoparticles at elevated temperature, Fe-MOFRs were premeditatedly introduced into the alumina powder matrix to construct the composite membrane layer. Results showed that the introduction of MOFRs could reduce the thickness of the membrane layer, attributing to the sacrificial organic linkers and high activity of Fe-MOFR-derived Fe2O3 nanoparticles. However, the thickness of the formed composite membrane layer abnormally increased once MOFRs were overloaded due to the aggregation. Impressively, the surface roughness and Young modulus of the membrane layer were characterized using atomic force microscopy (AFM). The Young modulus of pure alumina membranes showed the same trend as the height, while the trend gradually reversed once Fe-MOFRs were introduced, suggesting that the binding strength between the Fe-MOFR derived Fe2O3 nanoparticles were greatly enhanced. The composite membranes showed improved pure water flux and reduced filtration resistance.

Photoresponse properties of green-assisted Fe3O4 nanoparticles supported activated carbon

The photoresponse properties of green synthesized Fe3O4 (gFe3O4) supported-activated carbon (AC/g-Fe3O4) were studied using a photocurrent characterization approach. Preliminary UV–Vis analysis suggested a reduction in the band gap energy when activated carbon is incorporated into gFe3O4 nanoparticles (2.61 → 1.57 eV). The current-voltage characteristics indicate semiconductor features for both gFe3O4 and AC/gFe3O4 nanoparticles. The photodetector measurements indicate a significantly enhanced response for AC/gFe3O4 and can be attributed to increased rectification and photogenerated carriers emanating from the activated carbon incorporation. The study proposes AC/gFe3O4 nanocomposite as a novel material that can be used for the fabrication of photodetectors and other related optoelectronic devices.

Carbonization and Gasification of Cow‐Dung and Fe3O4 Nanoparticles at Different Operating Conditions for Hydrogen Production

AbstractCow dung is an abundant agricultural by‐product that poses disposal challenges. Converting this waste into a valuable energy resource aligns with sustainable waste management practices and contributes to a circular economy. This research aims at Cow dung disposal by carbonization and gasification for hydrogen generation and maximizes it by optimizing the process parameters. In the pyrolysis‐carbonization process, the influence of temperature on cow dung and its biochar characteristics was initially investigated. On the cow dung feedstock, different operating temperatures at about 400, 500, and 600 °C and response times of about 30, 60, and 120 min were tested. With CD450 as the feedstock, the gas concentrations and hydrogen yield were around 62 vol% and 0.69 m3 kg−1, respectively, for longer reaction times. Similar to this, the gas concentration and yield value for hydrogen at 600 °C gasification temperature is around 64 vol% and 0.91 m3 kg−1. Cow dung is evidently acceptable for larger hydrogen production at higher gasification temperatures and reaction times when the carbonization temperature is 450 °C. In addition, when compared to feedstock without adding nanoparticles, including Fe3O4 nanoparticles may increase the hydrogen concentration and yield by around 13.5 % and 4.21 %, respectively.

Construction and characterization of Fe3O4@SiO2-Dop/Amide-BTA-pd(0) nanocomposite as a novel and efficient nanomagnetic recoverable catalyst for synthesis of 5-substituted 1h-tetrazoles in water

The development of efficient, and environmentally friendly catalytic systems for synthesis of 5-substituted 1H-tetrazoles is an important challenge in organic synthesis because tetrazole derivatives are well known in medicinal chemistry with many biological activities such as anti-bacterial, anti-fungal, anti-allergic, anti-viral, anti-cancer, reducing blood pressure, and so on. In this research, we fabricated a palladium(0) complex stabilized on magnetic Fe3O4 nanoparticles modified with dopamine and benzo[d]thiazole-2-carbonyl chloride [Fe3O4@SiO2-Dop/Amide-BTA-Pd(0)] (1) and evaluated its catalytic behavior in the synthesis of 5-substituted 1H-tetrazoles through one-pot tandem reactions of aryl halides with K4[Fe(CN)6] and sodium azide under eco-friendly conditions. One-pot tandem reactions of aryl halides with K4[Fe(CN)6] and sodium azide were conducted using a catalytic amount of 1 in the presence of potassium carbonate in water at 100 °C for 2 h the 5-substituted 1H-tetrazole products were obtained in high to excellent yields. At the end of the reaction, 1 can be easily recycled and the products obtained had high purity.

TiO2 and ZnO Nanoparticles Immobilized on Magnetic Sulfonated Melamine‐Formaldehyde: Structure Identification and Performance as Recyclable Catalysts for the Biginelli Reaction

AbstractSulfonated melamine‐formaldehyde (SMF) containing high dispersed TiO2 and ZnO nanoparticles were fabricated into magnetic nanocomposites by two different method material incorporation protocols, including calcination and wet impregnation. Their catalytic performance was investigated toward Biginelli reaction. For the preparation of the first catalyst series, a two‐step protocol was used. Initially, Fe3O4 nanoparticles were coated with SMF (Fe3O4/SMF). Subsequently, they were decorated consecutively with TiO2 (Fe3O4/SMF/TiO2) and ZnO (Fe3O4/SMF/ZnO). The second set of catalysts was prepared using a two‐step process. Fe3O4 nanoparticles were first used to modify SMF (SMF/Fe3O4). Following the initial step, the surface of SMF/Fe3O4 was decorated with both TiO2 (SMF/Fe3O4/TiO2) and ZnO (SMF/Fe3O4/ZnO). To understand the characteristics of the synthesized nanocomposites, a variety of characterization techniques were employed. New catalysts enabled the rapid synthesis (30–45 min) of a range of biologically active 3,4‐dihydropyrimidinones based on the Biginelli reaction with high yields (70–95 % isolated).

Magnetic recyclable chitosan-graphene immobilized microcystinase A: Removal of microcystins from harmful microcystis blooms

Harmful Microcystis blooms and microcystins have become a major hidden threat to the safety of the water environment. The application of enzymatic degradation of microcystins has been severely limited by the complex environment. In this study, chitosan-graphene (CG), prepared from green biomass, was employed as matrix material, loaded with 100–200 nm Fe3O4 nanoparticles (MCG) and immobilized microcystinase A (MlrA@MCG). The preparation of MlrA@MCG was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer and fluorescence labelling. The results of the activity analysis demonstrated that MlrA@MCG exhibited superior degradation activity for MCs, as well as enhanced heat and alkaline resistance in comparison to free MlrA. Furthermore, MlrA@MCG can be recovered simply by means of a magnetic field, and its activity remains at 48.6 % after 10 repeated uses. More importantly, MlrA@MCG and the degradation products of MC-LR were not found to be cytotoxic to human cells. It is interesting that the immobilization of MlrA resulted in a reduction in the cytotoxicity of MCG. 0.2 U of MlrA@MCG can still degrade MC-LR from 232.64 μg L−1 to 94.39 μg L−1 in water from simulated severe Microcystis blooms within 24 h, showing excellent catalytic activity and stability. The study proposed a secure and efficacious approach for the elimination of microcystins from harmful Microcystis blooms, offering a promising avenue for the improvement of environmental safety.

Evaluation of magnetic hyperthermia, drug delivery and biocompatibility (bone cell adhesion and zebrafish assays) of trace element co-doped hydroxyapatite combined with Mn-Zn ferrite for bone tissue applications.

The treatment and regeneration of bone defects, especially tumor-induced defects, is an issue in clinical practice and remains a major challenge for bone substitute material invention. In this research, a composite material of biomimetic bone-like apatite based on trace element co-doped apatite (Ca10-δ M δ (PO4)5.5(CO3)0.5(OH)2; M = trace elements of Mg, Fe, Zn, Mn, Cu, Ni, Mo, Sr and BO3 3-; THA)-integrated-biocompatible magnetic Mn-Zn ferrite ((Mn, Zn)Fe2O4 nanoparticles, BioMags) called THAiBioMags was prepared via a co-precipitation method. Its characteristics, i.e., physical properties, hyperthermia performance, ion/drug delivery, were investigated in vitro using osteoblasts (bone-forming cells) and in vivo using zebrafish. The synthesized THAiBioMags particles revealed superparamagnetic behaviour at room temperature. Under the influence of an alternating magnetic field, THAiBioMags particles demonstrated a change in temperature, indicating their potential for magnetic hyperthermia, in which THAiBioMags further exhibited a specific absorption rate (SAR) value of 9.44 W g-1 (I = 44 A, H = 6.03 kA m-1 and f = 130 kHz). In addition, the as-prepared particles demonstrated sustained ion/drug (doxorubicin (DOX)) release under physiological pH conditions. Biological assay analysis revealed that THAiBioMags exhibited no toxicity towards osteoblast cells and demonstrated excellent cell adhesion properties. In vivo studies employing an embryonic zebrafish model showed the non-toxic nature of the synthesized THAiBioMags particles, as revealed by evaluation of the survivability, hatching rate, and embryonic morphology. These results could potentially lead to the design and fabrication of magnetic scaffolds to be used in therapeutic treatment and bone regeneration.

Extraction and detection of sulfonamide antibiotics in milk using magnetic solid-phase adsorbent based on molecular mechanics and DFT calculations

Based on the foundation of calculations in molecular mechanics and density functional theory (DFT) for in-depth mechanistic studies, this paper proposes the sample multi-residue analysis method of five common sulfonamide antibiotics (SAs) in milk. Fe3O4 nanoparticles modified magnetic graphene oxide nanoribbons (Mag-GONRs) with superior dispersibility and dispersion stability, were developed and firstly utilized to rapidly extract residual SAs from milk. Therefore, various SAs in complex samples could be simultaneously determined solely by high performance liquid chromatography-ultraviolet detector (HPLC-UV) without the need for complicated pretreatment processes. In order to obtain satisfactory extraction efficiency, indispensable investigation and optimization were conducted on some parameters influencing the extraction efficiency. And the extracted SAs were determined by. Good linearity for all analytes was achieved with appropriate correlation coefficients (R2 higher than 0.9978). The limits of detection ranged from 0.060 to 0.075 ng·mL−1. Recoveries of the sulfonamides in spiked milk samples were between 79.6 % and 114.6 %, with relative standard deviations within 12 %. Interestingly, with the assistant of computational chemistry, the efficient extraction of Mag-GONRs onto SAs has been validated at the molecular and quantum levels, further elucidating the adsorption mechanism based on non-covalent interactions. In the context of theoretical research and experimental results mutually supporting each other, a practical detection method with actual application value has been proposed in monitoring the residual sulfonamides in milk by the common devices.

Foliar Uptake and Distribution of Metallic Oxide Nanoparticles in Maize (Zea mays L.) Leaf.

The foliar uptake of Fe3O4, Cr2O3, CuO, and ZnO nanoparticles (NPs) by maize (Zea mays L.) was studied in a lab-scale experiment. The significant increase of Fe concentrations in leaves exposed to Fe3O4 was observed in both stomatal closing and stomatal opening treatments, suggesting the presence of a nonstomatal uptake. In parallel treatments with equal doses of Fe3O4 (∼200 nm), Cr2O3 (∼300 nm), CuO (∼30 nm), and ZnO (∼40 nm) (20-200 μg), the retention percentage of Fe in the leaves (21.0-69.0%) was higher than that of Cr, Cu, and Zn (0.5-14.0%). The steric hindrance effect seems more important for NPs of >200 nm, while hydrophobic surface and negative charge promote the foliar uptake of NPs smaller than 200 nm. The accumulation of NPs in the cuticle was observed through dark-field hyperspectral microscopy. Cr2O3, Fe3O4, and CuO NPs were difficult to penetrate the cuticle. In comparison, ZnO further migrated and distributed within the extracellular space of epidermal and mesophyll cells of the exposed leaf, possibly due to its comparatively higher solubility and hydrophilicity. The findings highlight the potential of the nonstomatal uptake, which might be a critical route for metallic oxide NPs to enter the food chain.

Annealing-induced transformation of nanocomposites based on Ni0.5Zn0.5Fe2O4 nanoparticles entangled with functionalized MWCNTs by ex-situ synthesis: Unveiling modified physical properties

The physicochemical properties of NZFO/f-MWCNTs composites based on 5 wt% of Ni0.5Zn0.5Fe2O4 (NZFO) nanoparticles and functionalized multi-walled carbon nanotubes (f-MWCNTs) synthesized via ex-situ method are presented. The influence of annealing on the as-received hybrids is discussed. The structural and microstructural analysis confirms the efficiency of the synthesis process. The slight redistribution of cations over tetrahedral and octahedral sites is noted by Raman and X-ray photoemission (XPS) studies. The NZFO crystallite size is almost stable over sample processing, but the presence of single particles, clusters and aggregates on the f-MWCNTs’ surface is proven. The XPS spectra comparison reveals the domination of nanotubes as designed. The deconvoluted Fe2p lines confirm the iron redistribution slightly modified by annealing. The magnetic properties analysis revealed the cluster-glass state of NZFO particles. The core-shell-like structure with a magnetic core and disordered layer is evidenced. The influence of Fe-based carbon matrix residues in all hybrids was detected.

A DNA machine-based magnetic resonance imaging nanoprobe for in vivo microRNA detection

In situ monitoring microRNA (miRNA) expression in vivo holds immense potential for directly visualizing the occurrence and progression of tumors. However, the significant barrier to developing a probe that can overcome the low abundance of miRNAs while providing an output signal with unlimited tissue penetration depth remains formidable. In this study, we developed a DNA machine-based magnetic resonance imaging nanoprobe (MRINP) for amplified detection of miR-21 in vivo. The MRINP was constructed with superparamagnetic Fe3O4 nanoparticles (NPs), paramagnetic Gd-DOTA complexes, and miR-21-activated DNA machines; the DNA machine was composed of hairpin DNAzyme (HD) strands serving as the DNAzyme walker and hairpin substrate (HS) strands serving as the track. Once uptake into tumor cells, the intracellular miR-21 specifically recognized and hybridized with the HD strand, restoring the activity of DNAzyme. Subsequently, the DNAzyme walker autonomously traveled on the surface of MRINP, and each step movement of the DNAzyme walker resulted in the cleavage of its substrate strands and the ensued release of the Gd-DOTA complex-labeled oligonucleotides, turning on the T1 signal of Gd-DOTA complexes for in situ imaging of miR-21 in tumor-bearing mice. This strategy would offer a promising approach for mapping tumor-specific biomarkers in vivo with unlimited penetration depth.

Magnetic activated carbon for the removal of methyl orange from water via adsorption and Fenton-like degradation

Water pollution caused by organic dyes is a critical environmental issue. Although activated carbon (AC) is commonly used for dye adsorption, its effectiveness is limited by challenges in separation and regeneration. To address these limitations, a convenient recyclable magnetic activated carbon (MAC) was fabricated via co-precipitation and calcination method, serving as adsorbent and catalyst for methyl orange (MO) removal through a Fenton-like degradation process. Characterization techniques, including XRD, FTIR, SEM and TEM, confirmed that Fe3O4 nanoparticles (10–20 nm) were uniformly dispersed on AC surface. The MAC maintaining a high surface area (997 m2/g) and pore volume (0.795 cm3/g) and exhibited superparamagnetic properties with a saturated magnetization of 5.52 emu/g, enabling effective separation from aqueous solutions by magnet. Batch adsorption studies revealed that MO adsorption onto MAC followed pseudo-second-order kinetic and Freundlich isotherm model, with a maximum adsorption capacity of 205 mg/g at 25 °C. Thermodynamic analysis showed that the adsorption process was spontaneous and endothermic. Simultaneous degradation of MO and in-situ regeneration of MAC were achieved via Fenton-like reaction using sodium persulfate (PS). Under a PS concentration of 9 mmol/L, the MO removal efficiency near 95% after 60 min, with a total organic carbon (TOC) reduction of 83.1%. The reaction of Fe3O4 and oxygen functional groups on AC surface with PS facilitated the generation of SO4•-, thereby enhancing catalytic degradation of MO. The degradation efficiency improved as the temperature increased from 25 °C to 45 °C. Cycle tests demonstrated that the MO removal efficiency of MAC remained above 90% after 5 cycles of regeneration. Overall, this study highlights the potential of MAC for efficient removal of organic dyes from water through the coupling of adsorption and Fenton-like degradation, providing a promising solution for addressing water pollution challenges.

Constructing ultralow-loading Cu single atoms/Fe2O3 particles on Nb2C MXenes for efficient utilization of atomic H to boost electrochemical debromination

Bromate is a commonly identified carcinogenic and genotoxic disinfection byproduct in water. Electrochemical debromination is an environmentally friendly and effective approach but it often suffers the limited reducing atomic H (H*) ability and high metal catalyst dosage. In this study, a unique composite catalyst comprised of ultra-low loading Cu single atoms (0.016 wt%) and Fe2O3 nanoparticles supported on a Nb2C MXene (denoted as Cu0.2/Fe0.1/Nb2C) was synthesized by one-step high-temperature molten salt method. The Cu0.2/Fe0.1/Nb2C significantly outperformed the Nb2C, Cu0.2/Nb2C and Fe0.1/Nb2C counterparts in the electrochemical debromination with a 94.2 % removal efficiency of bromate. It is revealed that the introducing of Cu single atoms, efficiently promotes the adsorption of H* and inhibition of competitive H2 evolution. The incorporation of Fe2O3 nanoparticles significantly increased the electronic metal-support interaction effect between the metal components and Nb2C, thereby forming a noticeable electronic cloud bridge to facilitate efficient charge transfer. Ultimately, the synergistic interplay between Cu single atoms and Fe2O3 nanoparticles plays a crucial role in achieving the remarkable removal performance of bromate. This work not only presents a significant instance of a synergistic catalyst involving metal single atoms and metal nanoparticles for effective electrochemical debromination but also advances the understanding of the electronic metal-support interaction.

Fe3O4/Au@SiO2 nanocomposites with recyclable and wide spectral photo-thermal conversion for a direct absorption solar collector

The Fe3O4-based photothermal materials have been widely applied for the recycling of heavy metal nanoparticles to avoid secondary pollution in the utilization of solar energy owing to excellent magnetic properties. However, the narrow absorption band of Fe3O4 or metal nanoparticles limits their capacity for solar energy harvesting. In this paper, a recyclable and wide spectral photo-thermal conversion system (Fe3O4/Au@SiO2) based on Fe3O4 nanospheres and SiO2-modified Au nanorods (NRs) is prepared. Owing to the strong coupling effect between Fe3O4 and different Au NRs, the wide and strong absorption band from 400 nm to 1100 nm is obtained. Under the influence of magnetic field, the temperature change of nanofluids (NFs) at different positions can be controlled. When the concentration is 0.0467 vol%, the solar energy absorption fraction reaches 96.50 %. Besides, the photothermal performance of Fe3O4/Au@SiO2 NFs at different flow rates is investigated and the results show that temperature rise decreases as increasing flow rate. Finally, a water evaporator device based Fe3O4/Au@SiO2 NFs is developed. The maximum water evaporation rate of 2.6 kg m−2 h−1 can be reached and the movement of evaporator on water can be operated using magnetic field, showing great photothermal conversion performance and recovery potential in practical applications.

Purification of mercury in Ciujung River water, Banten province, Indonesia by adsorption method using Fe3O4 nanoparticles

The Ciujung River, one of the main rivers in Banten province, Indonesia, plays an important role in agriculture and sanitation. However, the increasing use of heavy metals, especially mercury, by industries along the Ciujung River has caused significant environmental pollution. This issue requires considerable attention to ensure that environmental problems can be resolved immediately. This study evaluated the feasibility of Fe3O4 as a potential material to adsorb mercury in Ciujung River water originating from industrial waste. The adsorption efficiency was assessed by examining the effects of pH, adsorbent weight, and contact time. In addition, the adsorption capacity of Fe3O4 was analyzed using adsorption kinetics and isothermal models. The findings of the study showed that the adsorption process of Hg(II) using Fe3O4 followed pseudo-first-order kinetics with an R2 value of 0.998. Furthermore, the research data correlated well with the Freundlich isotherm. After Hg(II) was treated with Fe3O4 for a contact time of 90 min, its concentration in pure water samples was reduced, with an adsorption capacity of 263.04 mg/g. The study also evaluated the reusability and stability of Fe3O4 to reduce Hg(II) in Ciujung River water samples. Fe3O4 achieved a maximum adsorption capacity of 218.17 mg/g and was able to selectively absorb Hg(II) even in the presence of other heavy metals, with a desorption rate of 99.39 %. The desorption rate remained high after the fifth cycle, with a value of 87.65 %. These results indicate that Fe3O4 has strong potential as an adsorbent for treating industrial wastewater from the Ciujung River.

Enhanced biodegradation of lignin and lignocellulose constituents in the pulp and paper industry black liquor using integrated magnetite nanoparticles/bacterial assemblage

The study was designed to explore the efficiency of magnetite nanoparticles (Fe3O4 NPs)/bacterial cell assembly to biodegrade lignin and lignocellulose, decontaminate pulp and paper-contaminated wastewater and optimize lignin adsorption by Fe3O4 NPs. Water samples were collected from three paper and carton manufacturing companies, Alexandria Governorate, Egypt. Pseudomonas otitidis MCC10330, the most active and promising strain among 10 previously screened indigenous and exogenous isolates, was selected and decorated with magnetic Fe3O4 Nanoparticles, that were prepared by the co-precipitation method, characterized and used to decontaminate paper and pulp effluent in a batch mode bioassay for 4 h. Fe3O4 NPs/bacterial cell assembly achieved the highest removals (64.1, 52.0, 54.3 and 66.6%) of TSS, COD, BOD, and Total Tannin and Lignin after 1, 4 and 4 h, reaching residual concentrations (RCs) of 322, 216, 112 and 7 mg/L, which are still slightly higher (5.35, 2.7 and 1.86-fold) than their maximum permissible limits (MPLs), respectively. RCs of pH, DO and TDS in the treated effluent are accepted for safe discharging. Maximum lignin adsorption and removal (82.14%) using Fe3O4 NPs was achieved at the optimized conditions (pH 6, Fe3O4 NPs dosage of 100 mg and 10 min contact time). Results confirmed that the proposed magnetite-coated Pseudomonas otitidis treatment system is highly efficient and recommended to treat the highly contaminated pulp and paper wastewater. Also, as far as we know, this integrated assemblage is the first time to be used as a novel, very promising, eco-friendly, renewable and economical biotechnological approach to minimize/eliminate the involved pollutants with the least running time.

Highly sensitive magnetic particle imaging of abdominal aortic aneurysm NETosis with anti-Ly6G iron oxide nanoparticles

Abdominal aortic aneurysms (AAA) are a significant health concern in developed countries due to their considerable mortality rate. The crucial factor of the progression of AAA is the release of neutrophils and neutrophil extracellular traps (NETs). Magnetic particle imaging (MPI) is a new imaging technique that offers the capability to detect superparamagnetic iron oxide nanoparticles (SPION) with exceptional sensitivity. We aimed to investigate the functional imaging of MPI for the detection and monitoring of neutrophil infiltration within AAA. A novel multimodal imaging agent targeting neutrophils, PEG-Fe3O4-Ly6G–Cy7 nanoparticles (Ly6G NPs), were designed by coupling Fe3O4 nanoparticles with Ly6G antibodies and Cy7. The targeting and sensitivity of Ly6G NPs were assessed using MPI and fluorescence imaging (FLI) in the AAA mouse model. After the inhibition of NETosis, the degree of neutrophil infiltration and AAA severity were assessed using MPI with Ly6G NPs. Ly6G NPs accurately localized and quantitatively analyzed AAA lesion sites in mice using MPI/FLI/CT. Compared to the control group, elevated MPI and FLI signal intensities were detected at the abdominal aortic lesion site, and neutrophil infiltration and NETs accumulation were detected by histological analysis in the AAA models. After the inhibition of NETs accumulation in vivo, pathological damage in the abdominal aorta was significantly reduced, along with a decrease in the accumulation of Ly6G NPs and MPI signals. This multimodal MPI strategy revealed that nanoparticles targeting Ly6G can be used to detect neutrophil infiltration within AAA and monitor AAA severity.