Magnetic Hybrid Material Research Articles

A Versatile Magnetic Nanoplatform for Plug-and-Play Functionalization: Genetically Programmable Cargo Loading to Bacterial Magnetosomes by SpyCatcher "Click Biology".

Bacterial magnetosomes ("MAGs") represent a promising class of magnetic iron oxide nanoparticles with exceptional material characteristics and high application potential in the biomedical and biotechnological field. For the surface functionalization of MAGs with different protein cargos, their enveloping membrane can be addressed by genetic means. However, the expression of foreign polypeptides as translational fusion to magnetosome membrane proteins is still laborious and lacks versatility as the generated particles are monospecific and thus restricted to predetermined functions. Utilizing the SpyTag-SpyCatcher (ST-SC) bioconjugate system, we here establish a flexible platform for the targeted nanoassembly of multifunctional MAGs that combines the rapidity of chemical coupling (e.g., by cross-linking reactions) and the unmatched selectivity and controllability of in vivo functionalization. MAGs genetically engineered to display either SC- or ST-connectors are shown to efficiently bind a variety of complementary tagged (protein) cargo. Specifically, we cover a broad spectrum of representative functional moieties and foreign cargo (such as enzymes, antibodies, fluorophores, and silica beads) with relevance in biotechnology and biomedicine and demonstrate the interchangeability of the MAGs-adapted ST-SC system. For the controlled generation of artificial shells surrounding the particles, SC-MAGs are effectively coated by protein-corona proteins. The potential of the here-provided toolkit is even more enhanced by using SC-MAGs as an affinity tool for selective protein pulldown in vitro and in vivo. Overall, this innovative technology turns bacterial MAGs into a flexible magnetic nanoscaffold for the targeted plug-and-play display of virtually unlimited additional functionalities, thereby generating a multitude of magnetic hybrid materials that can be used in many applications.

Silk Fibroin Film Decorated with Ultralow FeCo Content by Sputtering Deposition Results in a Flexible and Robust Biomaterial for Magnetic Actuation.

Magnetically responsive soft biomaterials are at the forefront of bioengineering and biorobotics. We have created a magnetic hybrid material by coupling silk fibroin─i.e., a natural biopolymer with an optimal combination of biocompatibility and mechanical robustness─with the FeCo alloy, the ferromagnetic material with the highest saturation magnetization. The material is in the form of a 6 μm-thick silk fibroin film, coated with a FeCo layer (nominal thickness: 10 nm) grown by magnetron sputtering deposition. The sputtering deposition technique is versatile and eco-friendly and proves effective for growing the magnetic layer on the biopolymer substrate, also allowing one to select the area to be decorated. The hybrid material is biocompatible, lightweight, flexible, robust, and water-resistant. Electrical, structural, mechanical, and magnetic characterization of the material, both as-prepared and after being soaked in water, have provided information on the adhesion between the silk fibroin substrate and the FeCo layer and on the state of internal mechanical stresses. The hybrid film exhibits a high magnetic bending response under a magnetic field gradient, thanks to an ultralow fraction of the FeCo component (less than 0.1 vol %, i.e., well below 1 wt %). This reduces the risk of adverse health effects and makes the material suitable for bioactuation applications.

Preparation of magnetic coconut clothing biochar for extracting neonicotinoid insecticides from environmental water samples

In this study, the magnetic coconut clothing biochar hybrid materials were successfully prepared by in-situ method. The obtained magnetic biochar was characterized in detail by using series of analytical techniques. The results showed that the magnetic hybrid materials presented alveolate network structures with abundant large pores and good magnetic separation ability with Fe3O4 nanoparticles obviously attached on the surface of biochar. The magnetic biochar hybrid materials were used as adsorbents during magnetic solid-phase extraction process for extracting neonicotinoid insecticides from environmental water samples. The adsorption and desorption parameters (adsorption time, elution condition, sample volume, sample pH) affecting magnetic solid-phase extraction efficiency were carefully investigated. Under the optimum conditions (adsorption for 15 min, 5 % formic acid-acetonitrile as elution condition, 50 mL of sample volume, 15 mg of magnetic biochar, pH at 5.0), the magnetic solid-phase extraction process based on magnetic coconut clothing biochar hybrid materials coupled with high performance liquid chromatography tandem mass spectrometry for enriching and detecting neonicotinoid insecticides in environmental water samples was established. The good linear relationship in the range of 0.5–200 ng mL−1 with correlation coefficients greater than 0.9989 and the lower limits of detection (0.0017–0.0069 ng·mL−1) were obtained. The recovery in the spiked water samples was in the range of 68.6 %-104.0 % with relative standard deviation from 0.4 % to 9.3 %. These results demonstrated that the established method was highly sensitive, convenient and repeatable for directly analyzing trace neonicotinoid insecticides in environmental water samples. More importantly, the novel biochar from coconut clothing was introduced into sample pretreatment to enrich trace organic pollutants.

Synthesis, properties and applications of new hybrid material based on native/magnetically modified sepiolite and chitosans

The study introduces novel hybrid materials containing native and magnetite-containing sepiolite (Sep, SepM respectively) and chitosans (Ch) of different molecular weights. The main objective of this work was to determine the properties of these materials, including the different types of stability (colloidal, gravitational and thermal) in systems containing sepiolite, in order to obtain effective, stable and easily producible hybrid materials with great potential for water and wastewater treatment. The following measurements and methods were performed to characterize the investigated system: low-temperature nitrogen adsorption–desorption, zeta potential analysis, UV–Vis, FT-IR, XRD, XRF, SEM-EDS, TGA, DSC and DTG. It was found that the complexes with high molecular weight chitosan exhibited the best stability of the systems. The same tendency was observed for the concentration dependence: the higher the chitosan concentration, the better the stabilization of the composites. Overall, this study shows that chitosan effectively improves the colloidal and gravitational stability of the composites. Due to its unique structure, the synthesized magnetic hybrid material has shown great advantages in the adsorptive removal of textile dyes such as anionic acid red 88 (AR88) and cationic methylene blue (MB) which can be easily removed from the dye solutions after its use using an external magnetic field.

A novel hybrid magnetic material based on three-phase saturated core fault current limiter

Installing a three-phase saturated core fault current limiter (TSFCL) is an effective method to limit the increasing short-circuit current in high-voltage alternating current (HVAC) systems. However, the traditional TSFCL uses silicon steels as its working material for the iron core, resulting in poor current-limiting effects, requiring a large DC excitation current, and having a slow response speed. Nanocrystalline alloys have advantages such as a lower saturation point, higher permeability in the unsaturated zone, and a steep B–H curve, making them highly suitable for TSFCL’s applications. However, their poor capability which withstands fault hindered their large-scale commercialization. Therefore, this paper proposes a novel hybrid magnetic material based on TSFCL (HMTFCL), where the materials of the working limbs are replaced by nanocrystalline alloys. Compared to TSFCL, the DC excitation current of HMTFCL decreases by 60.5%. And, the HMTFCL reduces the peak short-circuit current by 23%. Last, the magnetic flux intensity inside the working limb of HMTFCL is reduced to zero more quickly.

Detection of mercury(ii) in aqueous media using bodipy-functionalized magnetic fluorescent sporopollenin.

Pollution from heavy metal ions has become a major issue worldwide. Water pollution, particularly with heavy metals like mercury, is a global problem. Developing environmentally friendly, low-cost, high-efficiency, sensitive, and selective sensors for the detection of mercury(ii) ions in aqueous environments has attracted great interest in industry and academia. In this research paper, a bodipy-functionalized magnetic fluorescent MSp-TAB hybrid material was developed for detecting mercury(ii) in aqueous media. The magnetic fluorescent MSp-TAB hybrid material was characterized using FT-IR, SEM, EDX, XRD, and TGA. We studied the influence of diverse factors such as contact time, temperature, and pH on the detection of Hg(ii). The fluorometric study demonstrated that the developed magnetic-fluorescent hybrid material was sensitive/selective for Hg(ii) ions in the absence and presence of interfering ions with a limit of detection (LOD) of 2.72 μM. In conclusion, the developed magnetic fluorescent MSp-TAB hybrid material has demonstrated its applicability and potential for accurate, sensitive, and practical detection of Hg(ii) in tap water samples.

Fe3O4@MOF hybrid for supercilious recovery of Au(III) and Pd(II) from e-waste and spent as catalysts for cyclohexane oxidation

Improving the economic viability of the most successful precious metal catalysts is one of the significant challenges in renewable energy production. We designed a magnetic hybrid material based on Cu-pPDA MOF and Fe3O4 nanosphere for selective recovery of Au(III) and Pd(II) from e-waste. Owing to its superior maximum adsorption capacities of 1450 and 1236 mg/g for Au (III) and Pd(II), respectively, at 45 °C with the pH of 3 and 1, the sorbed samples were converted into catalysts through an annealing process to obtain carbon supported FeAu and FePd nanoparticles catalysts (FeAu/C and FePd/C). Furthermore, these catalysts were applied for the oxidation of cyclohexane and resulted that FeAu/C catalyst exhibited higher conversion rate of cyclohexane (93.2%) than FePd/C catalyst (88.3%). Mechanistic investigations suggested that synergetic effect of Fe and Au on the supported carbon promoted better bond cleavage of the O–O bond in cyclohexyl hydroperoxide, a crucial intermediate species in the oxidation of cyclohexane. This study provides an alternate approach for the sustainable preparation of highly desired catalytic materials.

Rational design of stimuli‐responsive magnetic polymer hybrid (nano)materials

AbstractCombining organic and inorganic materials is a fascinating strategy to produce hybrid materials that combine the advantages of both polymeric and inorganic materials. Among the various types of organic–inorganic hybrids, stimuli‐responsive magnetic polymer hybrids (RMPHs) are particularly promising materials for a wide variety of applications. While the magnetic properties are generally provided by the presence of magnetic nanoparticles, such as iron oxide nanoparticles, the polymeric compound brings the stimuli‐responsiveness, e.g. responsiveness to pH, temperature, redox reaction or irradiation. Furthermore, as the chemical structure and architecture of the polymeric materials are diverse and easily tunable, stimuli‐RMPHs have found applications in various domains, including catalysis, biotechnology, (bio)imaging and cancer therapy. Given the importance of the hybrids' shape and morphology for the targeted application, this review presents the possible synthetic strategies to rationally design stimuli‐RMPHs of various morphologies ranging from nanometric core–shell structures to nanogels, microgels and membranes. © 2023 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.

Microfabrication of covalent organic framework-based magnetic bio-ceramic beads for defluoridation of water

The magnetic hybrid material, namely, iron oxide/alginate–gelatin/hydroxyapatite/covalent organic framework (MAGHCOF)-based bio-hybrid beads were prepared and utilized for fluoride removal studies.

Rapid and quantitative determination of deoxynivalenol in cereal through the combination of magnetic solid-phase extraction and optical fiber-based homogeneous chemiluminescence immunosensor

An integrated strategy for the rapid and sensitive detection of deoxynivalenol in cereals was developed by combining Fe3O4 magnetic nanoparticle-modified metal organic framework-5-based magnetic solid-phase extraction and the optical fiber-based homogeneous chemiluminescence immunosensor. The hybrid magnetic material was prepared and characterized, exhibiting good enrichment capacity up to 1.68 mg/g. The competitive immunoassay-based homogeneous chemiluminescence immunosensor enabled washing-free and high-sensitivity detection of deoxynivalenol. Under optimized conditions, this immunosensor could detect deoxynivalenol as low as 46.7 pg/mL with a quantitatively linear range of 0.1 to 1000 ng/mL. The recoveries of this integrated detection strategy in rice, corn, and wheat ranged from 80.0 % to 118.2 %, 91.1 % to 116.7 %, and 80.0 % to 91.5 %, respectively, with a relative standard deviation that did not exceed 9.11 %. More importantly, it shows great consistency with the high-performance liquid chromatography-mass spectrometry in blind sample analysis. This integrated detection strategy provides a convenient approach for mycotoxins screening in cereals.

Determination of Hg(II) and Methylmercury by Electrothermal Atomic Absorption Spectrometry after Dispersive Solid-Phase Microextraction with a Graphene Oxide Magnetic Material.

The toxicity of all species of mercury makes it necessary to implement analytical procedures capable of quantifying the different forms this element presents in the environment, even at very low concentrations. In addition, due to the assorted environmental and health consequences caused by each mercury species, it is desirable that the procedures are able to distinguish these forms. In nature, mercury is mainly found as Hg0, Hg2+ and methylmercury (MeHg), with the latter being rapidly assimilated by living organisms in the aquatic environment and biomagnified through the food chain. In this work, a dispersive solid-phase microextraction of Hg2+ and MeHg is proposed using as the adsorbent a magnetic hybrid material formed by graphene oxide and ferrite (Fe3O4@GO), along with a subsequent determination by electrothermal atomic absorption spectrometry (ETAAS). On the one hand, when dithizone at a pH = 5 is used as an auxiliary agent, both Hg(II) and MeHg are retained on the adsorbent. Next, for the determination of both species, the solid collected by the means of a magnet is suspended in a mixture of 50 µL of HNO3 (8% v/v) and 50 µL of H2O2 at 30% v/v by heating for 10 min in an ultrasound thermostatic bath at 80 °C. On the other hand, when the sample is set at a pH = 9, Hg(II) and MeHg are also retained, but if the solid collected is washed with N-acetyl-L-cysteine only, then the Hg(II) remains on the adsorbent, and can be determined as indicated above. The proposed procedure exhibits an enrichment factor of 49 and the determination presents a linear range between 0.1 and 10 µg L-1 of mercury. The procedure has been applied to the determination of mercury in water samples from different sources.

Encapsulated peroxo-polyoxometalates into Fe2O3/C hybrid material carbonized from MIL-101(Fe) as efficient magnetic catalyst for desulfurization of fuel

Magnetic hybrid material dropped Fe2O3 particles in mesoporous carbon was prepared by pyrolysis of MIL-101(Fe) in the presence of nitrogen flow. Then, high activity peroxo-polyoxometallates (Bu4N)3PWxMo4-x (x = 0, 2, 4) were encapsulated into the magnetic porous carbon material Fe2O3/C through facile impregnation method to prepare magnetic supported catalysts (Bu4N)3PWxMo4-x@Fe2O3/C. The catalysts were characterized by several means and applied for extraction oxidation desulfurization (EODS) of model fuel. One synthesized catalyst, (Bu4N)3PW4@Fe2O3/C, exhibited nearly perfect catalytic activity, which could remove 99.9 % DBT in simulated fuel within 30 min at mild conditions, and it also showed good activity for other substrate sulfides including BT, 4-MDBT and 4,6-DMDBT. Furthermore, the catalyst (Bu4N)3PW4@Fe2O3/C has stable structure and good reusability, which shown removal efficiency of DBT of>90 % up to 8 cycles.

A polyethanolamine nanodendrimer as a magnetic hybrid material for fast adsorption of heavy metal contaminants

A polyethanolamine nanodendrimer as a magnetic hybrid material for fast adsorption of heavy metal contaminants

Impact of Sm2O3 onthe Morphological, Optical, Magnetic, and Pesticide Adsorption of Co3O4/PANI Hybrid Nanocomposites

Adsorption is one of the most favored procedures in advanced wastewater treatment. Magnetic hybrid materials have a great adsorption performance and excellent reusability in the industry. For this reason, the amazing roles of Sm2O3 doping on Co3O4/PANI hybrid nanocomposite materials were studied. Co3O4 nanoparticles were synthesized using the thermal decomposition technique where Sm2O3 doped Co3O4/ PANI hybrid nanocomposite materials were prepared via in situ oxidative polymerization. The X-ray analysis, technique results confirm the successful formation of neat Co3O4 nanoparticles with cubic phase and its presence in emeraldine phase of PANI matrix. X-ray reveals that the crystallinity of hybrid nanocomposite materials increases with increasing Sm2O3 doping ratio. HRTEM showed polycrystalline structure of Co3O4 nanoparticles and that the doped Sm2O3 was well incorporated and dispersed within the PANI matrix. The surfaces topography was studied by FESEM. UV–Vis diffuse reflectance spectrum revealed two characteristic bands of PANI that are shifted towards higher wavelengths with Sm2O3 doping ratio. The calculated indirect energy gaps were found to decrease from 2.83–2.56 eV which indicates a good response of the hybrid nanocomposite materials to the effect of the UV absorption. The magnetic properties of the investigated samples are measured by VSM. Ms was found to decrease with increasing Sm2O3, while Hc increase with Sm2O3 ratio which will hinder the domain walls motion. Adsorptive removal of chlorpyrifos could be ascribed as pseudo-second ordered and Langmuir model. The maximum adsorptive capacity was 36.9, 47.11, 63.8, and 83.03, 96.73 mg/g for PANI, Co3O4/PANI, Co3O4/PANI-2 wt% Sm2O3, Co3O4/PANI/−4 wt% Sm2O3, and Co3O4/PANI-6 wt% Sm2O3hybridnanocomposite materials, respectively.

Magnetic solid-phase extraction of bisphenol A from water samples using nanostructured material based on graphene with few layers and cobalt ferrite

In this study, magnetic hybrid materials composed of cobalt ferrite, natural organic matter, and graphene (CoFe2O4/NOM/graphene) were synthesized and applied as adsorbents in the magnetic solid-phase extraction (MSPE) of bisphenol A (BPA) from aqueous matrices. To our knowledge, no studies have been previously conducted using this material for MSPE. Techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and transmission electron microscopy (TEM) were used to investigate the composition and morphology of the adsorbent. The MSPE method was optimized considering the main parameters influencing the process, with the best results obtained using 50.0 mg of adsorbent, agitation at 150 rpm, total extraction time of 7.5 min, 10 mL of methanol as extractant, and pH between 4 and 10. BPA analysis was performed using HPLC-DAD and HPLC-FL, with the latter showing better sensitivity. The developed method provided a wide linear range from 0.1 to 5000 μg L−1, with limits of detection (LOD) and quantification (LOQ) of 0.022 and 0.072 μg L−1, respectively. The extraction procedure presented reproducibility (RSD) of 2.13–2.21% and excellent recoveries in the range 99.3–104%. The developed MSPE method using CoFe2O4/NOM/graphene proved to be simple, fast, and efficient for the analysis of BPA in a variety of aqueous matrices.

Study of mechanical and magnetic properties of magnet composite hybrid Fe3O4-NdFeB with matrix polyvinyl alcohol

In the present study material composite magnetite were synthesized by polyvinyl alcohol (PVA) matrix and filler hybrid Fe3O4-NdFeB, for enhancing mechanical and magnetic properties. Fe3O4 is obtained from the iron sands of East Lombok. The filler hybrid has gained its importance due to its low cost, substitute for pure BaFe. It’s possible to use it as a interest for many applications, especially as theragnostic agents for magnetic hyperthermia, drug delivery, and magnetic resonance imaging. This study aims to investigate the compressive strength, remanent magnetization value (Mr), coercivity (Hc) and maximum energy product value (BH) max. The composition of filler hybrid Fe3O4-NdFeB was varied at 10%: 50%, 20%: 40%, 30%:30%, and 40%: 20 % from a total mass (wt) of 5 grams. In addition, matrix PVA 40% wt. The test specimens produced the vacum infussion method. The results of this study indicate that the addition of Fe3O4 composition causes a decrease in mechanical properties (density, compressive strength), on the other hand, the addition of Fe3O4 causes an increase in the magnetic properties (Magnetic remanence (Mr), coersivity (Hc), maximum energy product (BH)) of the Fe3O4 - NdFeB hybrid magnetic composite material, with PVA binding matrices.

Use of a Hybrid Porous Carbon Material Derived from Expired Polysaccharides Snack/Iron Salt Exhibiting Magnetic Properties, for Hexavalent Chromium Removal

Nowadays, the scientific interest is focused more and more on the development of new strategies in recycling of waste products as well as on the development of clean technologies due to the increased environmental pollution. In this work we studied the valorization of an expired cheese-tomato flavor corn snack, which is polysaccharide food product, by producing advanced hybrid magnetic materials for environmental remediation purposes. The carbonization-chemical activation of this snack using potassium hydroxide leads to a microporous activated carbon with high surface area (SgBET ~800 m2/g). The magnetic hybrid material was synthesized via an in-situ technique using iron acetate complex as the precursor to produce iron based magnetic nanoparticles. The resulting material retains a fraction of the microporous structure with surface area SgBET ~500 m2/g. Such material consists, of homogenously dispersed magnetic isolated zero valent iron nanoparticles and of iron carbides (Fe3C), into the carbon matrix. The magnetic carbon exhibited high adsorption capacity in Cr(VI) removal applications following a pseudosecond order kinetic model. The maximum adsorption capacity was 88.382 mgCr(VI)/gAC at pH = 3. Finally, oxidation experiments, in combination with FT-IR, Mössbauer, and VSM measurements indicated that the possible Cr6+ removal mechanism involves oxidation of iron phases and reduction of Cr6+ to Cr3+.

Metal-organic framework-based magnetic dispersive micro-solid-phase extraction for the gas chromatography–mass spectrometry determination of polycyclic aromatic compounds in water samples

A magnetic hybrid material based on the use of the mixed-ligand Metal-Organic Framework (MOF) PUM198 is proposed for the magnetic dispersive micro solid-phase extraction (MD-μSPE) of the 16 polycyclic aromatic hydrocarbons (PAHs) included in the US-EPA priority pollutants list. PUM198 is a thermally robust MOF characterized by a doubly interpenetrated microporous framework in which Zn2+ ions and carboxylate groups define 2D planes that are pillared by a bis-pyridine-bis amide ligand containing a biphenyl scaffold. PUM198 revealed to be ideal to adsorb PAHs efficiently through non-covalent interactions. A Plackett-Burman Design followed by a Central Composite Design and the multicriteria method of the desirability functions were applied to find the optimal conditions for the extraction of the investigated PAHs, resulting in a reduced solvent consumption, i.e., 50 μL of solvent per extraction for 5 mL of sample, approximatively 3–20 times lower than those reported in previous studies, thus satisfying the principles of green analytical chemistry. Method validation proved the reliability of the method for the determination of PAHs at trace level, obtaining detection limits in the 6.7–27 ng/L range, good precision with RSDs% lower than 19% and recovery rates in the 99 (±13)–126 (±8)% range near the quantitation limit. Finally, the applicability of the method was demonstrated by analyzing underground water samples taken from contaminated sites

Preparation and characterization of Schiff-base modified Fe3O4 hybrid material and its selective adsorption for aqueous Hg2.

A Fe3O4 hybrid material (Fe3O4@SiO2-S2) modified by Schiff-base was prepared by grafting methyl acrylate (MA), ethylenediamine (EDA), and salicylaldehyde (SA) to the prepared magnetic hybrid material (Fe3O4@SiO2-NH2) successively; what's more, the structure was characterized by FTIR, XRD, SEM, TEM, and VSM. The results showed that the Fe3O4@SiO2-S2 has an obvious core-shell structure and a saturation magnetization of 45.9emu/g. Study on the adsorption of aqueous heavy metal ions showed that Fe3O4@SiO2-S2 posed selective adsorption for Hg2+ with the saturated adsorption capacity of 362mg/g (1.12mmol/g), which was superior to Fe3O4@SiO2-NH2, Fe3O4@SiO2-HO-S, and other adsorbents, at the condition of pH = 6, 45℃, the adsorption capacity remained 89% after 5 cycles of adsorption-desorption; what is more, adsorption equilibrium was reached at about 300min, and the adsorption isotherm conformed to the Langmuir isotherm adsorption model; in addition, pseudo-second-order model could be well described the adsorption kinetic process of Fe3O4@SiO2-S2 to Hg2+. The adsorption mechanism demonstrated that the N atoms of Schiff-base were mainly contributed to the adsorption of Hg2+; what is more, the N atom of tertiary amine and the O atoms of hydroxy and carbonyl also help to the adsorption of Hg2+.

Development of a magnetic hybrid material capable of photoinduced phase separation of iron chloride by shape memory and photolithography

FeCl3 in the polymer matrix can be partially ordered using photolithography. Ordered FeCl3 has improved magnetic susceptibility.