Commercial Fe3O4 Nanoparticles Research Articles

Development of an innovative analytical method for forensic detection of cocaine, antidepressants, and metabolites in postmortem blood using magnetic nanoparticles.

Cocaine and antidepressants rank high globally in substance consumption, emphasizing their impact on public health. The determination of these compounds and related substances in biological samples is crucial for forensic toxicology. This study focused on developing an innovative analytical method for the determination of cocaine, antidepressants, and their related metabolites in postmortem blood samples, using unmodified commercial Fe3O4 nanoparticles as a sorbent for dispersive magnetic solid-phase extraction (m-d-SPE), coupled with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis. An aliquot of 100 µL of whole blood and 5 µL of the internal standard pool were added to 30mg of nanoparticles. The nanoparticles were separated from the sample using a neodymium magnet inserted into a 3D-printed microtube rack. The liquid was then discarded, followed by desorption with 300 µL of 1/1/1 acetonitrile/methanol/ethyl acetate. The sample was vortexed and separated, and 1.5 µL of the organic supernatant was injected into the LC-MS/MS. The method was acceptably validated and successfully applied to 263 postmortem blood samples. All samples evaluated in this study were positive for at least one substance. The most frequent analyte was benzoylecgonine, followed by cocaine and cocaethylene. The most common antidepressants encountered in the analyzed samples were citalopram and fluoxetine, followed by fluoxetine's metabolite norfluoxetine. This study describes the first report of this sorbent in postmortem blood analysis, demonstrating satisfactory results for linearity, precision, accuracy, and selectivity for all compounds. The method's applicability was confirmed, establishing it as an efficient and sustainable alternative to traditional techniques for forensic casework.

Magnetically activated 3D printable polylactic acid/polycaprolactone/magnetite composites for magnetic induction heating generation

Additive manufacturing technology has attracted the attention of industrial and technological sectors due to the versatility of the design and the easy manufacture of structural and functional elements based on composite materials. The embedding of magnetic nanoparticles in the polymeric matrix enables the development of an easy manufacturing process of low-cost magnetically active novel polymeric composites. In this work, we report a series of magnetic composites prepared by solution casting method combining 5 to 60 wt.% of 140 pm 50 nm commercial Fe3O4 nanoparticles, with a semi-crystalline, biocompatible, and biodegradable polymeric blend made of polylactic acid (PLA) and polycaprolactone (PCL). The composites were extruded, obtaining 1.5 pm 0.2 mm diameter continuous and flexible filaments for fused deposition modelling 3D printing. The chemical, magnetic, and calorimetric properties of the obtained filaments were investigated by differential scanning calorimetry, thermogravimetric analysis, magnetometry, and scanning electron microscopy. Furthermore, taking advantage of the magnetic character of the filaments, their capability to generate heat under the application of low-frequency alternating magnetic fields (magnetic induction heating) was analyzed. The obtained results expose the versatility of these easy manufacturing and low-cost filaments, where selecting a desired composition, the heating capacity can be properly adjusted for those applications where magnetic induction plays a key role (i.e., magnetic hyperthermia, drug release, heterogeneous catalysis, water electrolysis, gas capture, or materials synthesis).Graphical This paper presents the manufacture of novel magnetically activated 3D printable filaments, low cost and easy to manufacture, whereby selecting the desired composition, the heating capacity (ρ) generated under the application of an alternating magnetic field (Happ) can be adjusted to the needs of the user.

Effective removal of brilliant green with magnetic barium phosphate composites: factor analysis and mechanism study.

In this work, magnetic barium phosphate (FBP) composites with different content of commercial Fe3O4 nanoparticles were easily prepared by a one-step hydrothermal method. FBP composites with a magnetic content of 3% (FBP3) were studied as the example for the removal of an organic pollutant (Brilliant Green, BG) from the synthetic medium. The adsorption study was executed under the variation of different experimental conditions, such as solution pH (5 ~ 11), dosage (0.02 ~ 0.20g), temperature (293 ~ 323K), and the contact time (0 ~ 60min) on the removal of BG. For comparison purposes, the one-factor-at-a-time (OFAT) approach and Doehlert matrix (DM) were both employed to investigate the factor impacts involved. FBP3 showed a high adsorption capacity of 1419.3 ± 10.0mg/g for at 25°C and pH = 6.31.The kinetics study revealed the pseudo-second-order kinetic model as the best-fitted model, and the thermodynamic data fit well with the Langmuir model.The possible adsorption mechanisms involved are the electrostatic interaction and/or hydrogen bonding of PO43-…N+/C-H and HSO4-…Ba2+ between FBP3 and BG. Furthermore, FBP3 showed good easy reusability and high capacities for BG removal. Our results provide new insights for developing low-cost, efficient, and reusable adsorbent to remove BG from industrial wastewater.

Enhancing water flux and antifouling properties of PES hollow fiber membranes via incorporation of surface‐functionalized Fe3O4 nanoparticles

AbstractBACKGROUNDIn this study, polyethersulfone (PES) hollow fiber membranes incorporated with surface‐functionalized iron oxide (Fe3O4) nanoparticles were developed in order to improve water flux and antifouling properties of PES membrane. Commercial Fe3O4 nanoparticles was coated by polydopamine (PDA), followed by functionalization using (3‐aminopropyl)triethoxysilane (APTES) and sulfonic acid to produce Fe3O4/PDA‐Amine and Fe3O4/PDA‐Sulf nanoparticles, respectively. All the nanoparticles‐modified membranes were synthesized using dope solution composed of different nanoparticles, followed by a series of instrumental characterization and filtration assessments.RESULTSIt is found that the membrane incorporated with Fe3O4/PDA‐Amine exhibited the best filtration performance, achieving water flux of 137.23 L m−2 h−1 bar−1 and bovine serum albumin (BSA) rejection of 92.16%. As a comparison, the pristine PES membrane only showed 82.60 L m−2 h−1 bar−1 and 71.92%, respectively. The membrane with Fe3O4/PDA‐Sulf also showed lower performance, recording 129.88 L m−2 h−1 bar−1 and 88.39%, respectively. The improved performance of the Fe3O4/PDA‐Amine‐modified PES membrane could be attributed to its lowest water contact angle (65.10°), highest porosity (68.14%), ideal pore size (65 nm) as well as good structural integrity. More importantly, the improved surface properties also led to outstanding fouling resistance, achieving flux recovery rate of 97%. This membrane also achieved excellent chemical oxygen demand (95.17%) and color (89.86%) reduction when tested using river water sample.CONCLUSIONOur work demonstrated a simple approach to functionalize the surface of Fe3O4 nanoparticles and showed the effectiveness of the surface‐functionalized Fe3O4 nanoparticles in improving not only the surface properties of PES membrane but also its filtration performance in terms of permeability, rejection and antifouling property. © 2021 Society of Chemical Industry (SCI).

Single-atom iron confined within polypyrrole-derived carbon nanotubes with exceptional peroxidase-like activity for total antioxidant capacity

Single-atom catalysts possess the advantages of robustness, maximum atomic utilization, and low cost, offering an efficient strategy to remarkably promote the catalytic performance of nanozymes. Herein, high-efficiency and durable Fe-N-doped carbon nanotubes (Fe-NC NTs) for enzyme mimicking are synthesized through a simple in-situ polymerization and subsequent pyrolysis process derived from polypyrrole (PPy) without additional acid etching treatment. The distinct tubular structure provides abundant accessible active sites and fast electron/mass transport, benefitting for the improved catalytic activity. Compared to commercial Fe3O4 nanoparticles, the Fe-NC NTs show an unprecedented peroxidase-like activity. Then we develop a simple colorimetric assay to detect H2O2 and ascorbic acid (AA) with a high sensitivity. Furthermore, the total antioxidant capacity (TAC) sensor for a series of real samples is constructed, which has been verified by a conventional cupric reducing antioxidant capacity (CUPRAC) strategy, demonstrating the reliability of the demonstrated peroxidase-like reaction. The high activity of tubular single-atom catalysts offers new insight to design high-performance nanozymes for promising sensing and exogenous dietary and healthcare applications.

Bioinspired Copper Single-Atom Catalysts for Tumor Parallel Catalytic Therapy.

The oxidation of intracellular biomolecules by reactive oxygen species (ROS) forms the basis for ROS-based tumor therapy. However, the current therapeutic modalities cannot catalyze H2 O2 and O2 concurrently for ROS generation, thereby leading to unsatisfactory therapeutic efficacy. Herein, it is reported a bioinspired hollow N-doped carbon sphere doped with a single-atom copper species (Cu-HNCS) that can directly catalyze the decomposition of both oxygen and hydrogen peroxide to ROS, namely superoxide ion (O2 •- ) and the hydroxyl radical (•OH), respectively, in an acidic tumor microenvironment for the oxidation of intracellular biomolecules without external energy input, thus resulting in an enhanced tumor growth inhibitory effect. Notably, the Fenton reaction turnover frequency of Cu species in Cu-HNCS is ≈5000 times higher than that of Fe in commercial Fe3 O4 nanoparticles. Experimental results and density functional theory calculations reveal that the high catalytic activity of Cu-HNCS originates from the single-atom copper, and the calculation predicts a next-generation Fenton catalyst. This work provides an effective paradigm of tumor parallel catalytic therapy for considerably enhanced therapeutic efficacy.

TiO2 nanoparticles removal by electrocoagulation using iron electrodes: Catalytic activity of electrochemical sludge for the degradation of emerging pollutant

Increase in use of TiO2-based nanoparticles induced the presence of TiO2 nanoparticles (TNPs) in water resources. TNPs have adverse impacts of human health and the ecosystems. Although, several studies demonstrated toxicity and health effects of TNPs, TNPs removal from water resources are limited. In this work, TNPs were removed from the aqueous solution by electrocoagulation (EC) process using iron electrodes. The effect of pH, applied current, and initial concentration of TNPs was investigated on TNPs removal. More than 95% of TNPs were eliminated under neutral pH, 100 mA applied current and 50 mg/L TNPs. Electrochemical sludge (ES) produced was considered as catalyst for peroxymonosulfate (PMS) activation to degrade ciprofloxacin (CIP) as an emerging pollutant. Iron species in ES was in the form of Fe3O4, which is confirmed by several methods. ES could activate PMS effectively to degrade 88% of CIP under optimum condition of 2 mM PMS, 0.1 g/L ES, and 60 min reaction time. The pseudo-first-order model was fitted for the PMS/ES process with a rate constant of 0.047 min−1. The catalytic activity of ES was kept for three-time use. However, iron leaching was considerable for the first use. Sulfate radical was the main agent of CIP degradation. ES was compared with commercial Fe3O4 nanoparticles for PMS activation in terms of CIP degradation and TOC removal. Finally, the use of electrochemical sludge can be a suitable strategy for minimizing waste and preparation of the catalyst.

A Facile synthesis of superparamagnetic Fe3O4 nanofibers with superior peroxidase-like catalytic activity for sensitive colorimetric detection of l-cysteine

Superaramagnetic Fe3O4 nanomaterials are good candidates as enzyme mimics due to their excellent catalytic activity, high stability and facile synthesis. However, the morphology of Fe3O4 nanomaterials has much influence on their enzyme-like catalytic activity. In this work, we have developed a simple polymer-assisted thermochemical reduction approach to prepare Fe3O4 nanofibers for peroxidase-like catalytic applications. The as-prepared Fe3O4 nanofibers show a higher catalytic activity than commercial Fe3O4 nanoparticles. The steady-state kinetic assay result shows that the Michaelis–Menten constant value of the as-obtained Fe3O4 nanofibers is similar to that of horseradish peroxidase (HRP), indicating their superior affinity to the 3,3′,5,5′-tetramethylbenzidine (TMB) and H2O2 substrate. Based on the outstanding catalytic activity, a sensing platform for the detection of l-cysteine has been performed and the limit of detection is as low as 0.028 μM. In addition, an excellent selectivity toward l-cysteine over other types of amino acids, glucose and metal ions has been achieved as well. This work offers an original means for the fabrication of superparamagnetic Fe3O4 nanofibers and demonstrates their delightful potential applications in the fields of biosensing, environmental monitoring, and medical diagnostics.

Effect of magnetite nanoparticles on dye absorption properties of magnetite@carbon composites

Magnetite@carbon (Fe3O4@C) composites were prepared using three kinds of Fe3O4 nanoparticles (NPs). All the Fe3O4@C composites could be easily separated from water by an external magnet. The Fe3O4 NPs synthesized by a microreactor system have the smallest size and narrowest size distribution among the three kinds of Fe3O4 NPs. The saturated capacity of the Fe3O4@C composite originating from microreactor-prepared Fe3O4 NPs to absorb Rhodamine B at 2 0 ∘C exceeds 135 mg g−1, which is 1.35 times as much as the value of the Fe3O4@C composite originating from traditional Fe3O4 NPs. This value for the Fe3O4@C composite using commercial Fe3O4 NPs as core is only 76 mg g−1. The Fe3O4@C composite using microreactor-prepared Fe3O4 NPs also has good retrievability and reusability.

Template‐Free Synthesis of Porous Fe3O4/SiOC(H) Nanocomposites with Enhanced Catalytic Activity

We present a template‐free synthesis of Fe3O4/SiOC(H) nanocomposites with in situ formed Fe3O4 nanoparticles with a size of about 50 nm embedded in a nanoporous SiOC(H) matrix obtained via a polymer‐derived ceramic route. Firstly, a single‐source precursor (SSP) was synthesized by the reaction of allylhydridopolycarbosilane (AHPCS) with Fe‐acetylacetonate [Fe(acac)3] at 140°C. The SSP was heat‐treated at 170°C to generate Fe3O4 nanocrystals in the cross‐linked polymeric matrix. Subsequently, the SSP was pyrolyzed at 600°C–700°C in argon atmosphere to yield porous Fe3O4/SiOC(H) nanocomposites with the high BET surface area up to 390 m2/g, a high micropore surface area of 301 m2/g, and a high micropore volume of 0.142 cm3/g. The Fe‐free SiOC(H) ceramic matrix derived from original AHPCS is nonporous. The in situ formation of Fe3O4 nanoparticles embedded homogeneously within a nanoporous SiOC(H) matrix shows significantly enhanced catalytic degradation of xylene orange in aqueous solution with H2O2 as oxidant as compared with pure commercial Fe3O4 nanoparticles.

Magnetic Fe3O4–FeB nanocomposites with promoted Cr(VI) removal performance

In this study, amorphous FeB alloy modified magnetite nanocomposites (Fe3O4–FeB) were facilely synthesized by interfacial reduction of commercial Fe3O4 nanoparticles with NaBH4. TEM, CS-STEM integrated with EDS, Mössbauer spectroscopy analysis confirmed the formation of Fe3O4–FeB, where a shell of amorphous FeB nanoparticles with 2–4nm in size was surrounded on the inner magnetite Fe3O4 part. Fe3O4–FeB displayed a promoted Cr(VI) removal efficiency compared with the bare Fe3O4 counterpart, the interfacial reduced Fe3O4 nanoparticles with hydrogen and/or with hydrazine hydride. XPS analysis evidenced that reduction of Cr(VI) on surface of the Fe3O4–FeB was the major contribution to the Cr(VI) removal. Tafel polarization analysis of the Fe3O4–FeB and aqueous boron species measurement indicated that high Cr(VI) removal efficiency with Fe3O4–FeB was highly depended on amorphous FeB alloy shell, in which boron element containing free electrons could accelerate the electron transfer from Fe to the adsorbed Cr(VI), as well reduce Fe(III) to Fe(II) and thus promote the Fe(III)/Fe(II) cycles. The efficient Cr(VI) removal under a wide range of pH values and its easy magnetic separation make the Fe3O4–FeB be a potential for Cr(VI) contaminated water treatment.

The on-bead digestion of protein corona on nanoparticles by trypsin immobilized on the magnetic nanoparticle

Proteins interacting with nanoparticles would form the protein coronas on the surface of nanoparticles in biological systems, which would critically impact the biological identities of nanoparticles and/or result in the physiological and pathological consequences. The enzymatic digestion of protein corona was the primary step to achieve the identification of protein components of the protein corona for the bottom-up proteomic approaches. In this study, the investigation on the tryptic digestion of protein corona by the immobilized trypsin on a magnetic nanoparticle was carried out for the first time. As a comparison with the usual overnight long-time digestion and the severe self-digestion of free trypsin, the on-bead digestion of protein corona by the immobilized trypsin could be accomplished within 1h, along with the significantly reduced self-digestion of trypsin and the improved reproducibility on the identification of proteins by the mass spectrometry-based proteomic approach. It showed that the number of identified bovine serum (BS) proteins on the commercial Fe3O4 nanoparticles was increased by 13% for the immobilized trypsin with 1h digestion as compared to that of using free trypsin with even overnight digestion. In addition, the on-bead digestion of using the immobilized trypsin was further applied on the identification of human plasma protein corona on the commercial Fe3O4 nanoparticles, which leads the efficient digestion of the human plasma proteins and the identification of 149 human plasma proteins corresponding to putative critical pathways and biological processes.

Efficient removal of trace antimony(III) through adsorption by hematite modified magnetic nanoparticles

Hematite coated magnetic nanoparticle (MNP@hematite) was fabricated through heterogeneous nucleation technique and used to remove trace Sb(III) from water. Powder X-ray diffraction, transmission electron microscopy (TEM), and alternating gradient magnetometry were utilized to characterize the prepared adsorbent. TEM image showed that MNP@hematite particles were spherical with size of 10–30nm. With saturation magnetization of 27.0emu/g, MNP@hematite particles could be easily separated from water with a simple magnetic process in short time (5min). At initial concentration of 110μg/L, Sb(III) was rapidly decreased to below 5μg/L by MNP@hematite in 10min. Sb(III) adsorption capacity of MNP@hematite was 36.7mg/g, which was almost twice that of commercial Fe3O4 nanoparticles. The removal of trace Sb(III) was not obviously affected by solution pH (over a wide range from 3 to 11), ionic strength (up to 100mM), coexisting anions (chloride, nitrate, sulfate, carbonate, silicate, and phosphate, up to 10mM) and natural organic matters (humic acid and alginate, up to 8mg/L as TOC). Moreover, MNP@hematite particles were able to remove Sb(III) and As(III) simultaneously. Trace Sb(III) could also be effectively removed from real tap water by MNP@hematite. The magnetic adsorbent could be recycled and used repeatedly.

Ultrafine Magnetite Nanopowder: Synthesis, Characterization, and Preliminary Use as Filler of Polymethylmethacrylate Nanocomposites

Magnetite (Fe3O4) nanoparticles prepared by microwave-assisted hydrothermal synthesis have been characterized in terms of morphological and structural features. Electron micrographs collected in both scanning (SEM) and transmission (TEM) modes and evaluations of X-ray powder diffraction (XRD) patterns have indicated the achievement of a monodispersed crystallite structure with particles having an average size around 15–20 nm. Structural investigations by Micro-Raman spectroscopy highlighted the obtainment of magnetite nanocrystals with a partial surface oxidation to maghemite (γ-Fe3O4). Preliminary attention has been also paid to the use of these magnetite nanoparticles as filler for a commercial polymethylmethacrylate resin. Hybrid formulations containing up to 3 wt% of nanoparticles were prepared by melt blending and characterized by calorimetric and thermogravimetric tests. For sake of comparison, same formulations containing commercial Fe3O4nanoparticles are also reported. Calorimetric characterization indicates an increase of both glass transition temperature and thermal stability of the nanocomposite systems when loaded with the synthesized magnetite nanoparticles rather then loaded with the same amount of commercial Fe3O4. This first observation represents just one aspect of the promising potentiality offered by the novel magnetic nanoparticles when mixed with PMMA.