Synthesis and properties of modified graphite encapsulated iron metal nanoparticles

Li, Shang-Shih; Chiu, Chien‐Wen; Chang, Ren-Wei; Liou, Yi-Rou; Teng, Mao‐Hua

doi:10.1016/j.diamond.2015.12.009

Cited by 8 publications

(4 citation statements)

References 27 publications

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“…1e). This value is higher than that obtained previously for Fe 7 C 3 @C NPs (54 emu/g) [18] and for Fe@C (63 emu/g) [20]. These data thus demonstrated that commercial Fe@C NPs possess superparamagnetic properties, have high level of magnetic saturation and can be chemically modified for future biological application.…”

Section: Resultsmentioning

confidence: 47%

“…Acid treatment was used for elimination of NPs with defective shells, as it was described earlier [19], along with some modification (see: “Methods”). Acid treatment of NPs surface also led to their hydrophilization [20]. Purified samples were characterized by their microstructure and size, and then the surface of NPs was modified by alkylcarboxylation and subsequent amination.…”

Section: Resultsmentioning

confidence: 99%

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Long-term live cells observation of internalized fluorescent Fe@C nanoparticles in constant magnetic field

et al. 2019

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BackgroundTheranostics application of superparamagnetic nanoparticles based on magnetite and maghemite is impeded by their toxicity. The use of additional protective shells significantly reduced the magnetic properties of the nanoparticles. Therefore, iron carbides and pure iron nanoparticles coated with multiple layers of onion-like carbon sheath seem to be optimal for biomedicine. Fluorescent markers associated with magnetic nanoparticles provide reliable means for their multimodal visualization. Here, biocompatibility of iron nanoparticles coated with graphite-like shell and labeled with Alexa 647 fluorescent marker has been investigated.MethodsIron core nanoparticles with intact carbon shells were purified by magnetoseparation after hydrochloric acid treatment. The structure of the NPs (nanoparticles) was examined with a high resolution electron microscopy. The surface of the NPs was alkylcarboxylated and further aminated for covalent linking with Alexa Fluor 647 fluorochrome to produce modified fluorescent magnetic nanoparticles (MFMNPs). Live fluorescent imaging and correlative light-electron microscopy were used to study the NPs intracellular distribution and the effects of constant magnetic field on internalized NPs in the cell culture were analyzed. Cell viability was assayed by measuring a proliferative pool with Click-IT labeling.ResultsThe microstructure and magnetic properties of superparamagnetic Fe@C core–shell NPs as well as their endocytosis by living tumor cells, and behavior inside the cells in constant magnetic field (150 mT) were studied. Correlative light-electron microscopy demonstrated that NPs retained their microstructure after internalization by the living cells. Application of constant magnetic field caused orientation of internalized NPs along power lines thus demonstrating their magnetocontrollability. Carbon onion-like shells make these NPs biocompatible and enable long-term observation with confocal microscope. It was found that iron core of NPs shows no toxic effect on the cell physiology, does not inhibit the cell proliferation and also does not induce apoptosis.ConclusionsNon-toxic, biologically compatible superparamagnetic fluorescent MFMNPs can be further used for biological application such as delivery of biologically active compounds both inside the cell and inside the whole organism, magnetic separation, and magnetic resonance imaging (MRI) diagnostics.

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Section: Resultsmentioning

confidence: 47%

Section: Resultsmentioning

confidence: 99%

Long-term live cells observation of internalized fluorescent Fe@C nanoparticles in constant magnetic field

et al. 2019

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“…Carbon-encapsulated magnetic NPs can be generated by several methods, such as metal–organic chemical vapor deposition (CVD), hydrothermal reaction, pyrolysis by detonation, thermolysis, gas condensation, arc discharge, high-energy electron-beam irradiation, cocarbonization of durene, and photoablation . However, magnetic NPs should be encapsulated prior to several applications to prevent possible aggregation in a liquid medium and to promote fast biodegradation. , Carbon-based materials such as shells are preferred over silica or polymers because of their elevated chemical and thermal stability, suitable conductivity and biocompatibility, and possible functionalization with various ligands . Encapsulation of metals or carbides inside graphitic shells was carried out by several methods, such as the evaporation of metals together with carbon in an arc discharge at high temperatures, pyrolysis of ferrocene, , and solvothermal carbonization of a mixture of durene and ferrocene molecules .…”

Section: Introductionmentioning

confidence: 99%

Graphene-Assisted Magnetic Iron Carbide Nanoparticle Growth

Alahmadi

Siaj

2018

ACS Appl. Nano Mater.

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Iron carbide nanoparticles (NPs) encapsulated by multilayer graphene, Fe3C@graphene, were produced by one-step chemical vapor deposition (CVD) at high temperature (950 °C) with ferrocene powder as a precursor and a copper foil surface as a catalyst. At high temperature, the ferrocene molecules adsorb dissociatively on copper catalysts, forming a layer of graphene decorated by core–shell Fe3C@graphene NPs. At high temperature, graphene has a low surface energy, allowing the lateral diffusion of iron atoms and carbon fragments to form NPs. The as-prepared core–shell Fe3C@graphene NPs have varying diameter from 50 to 80 nm, while the graphene shells vary from 8 to 40 graphene layers. The results demonstrate that the thickness of the graphene shell growth for NPs increases with increasing reaction time from 1 to 7 h. Graphene-assisted NP growth allows the formation of uniform core–shell Fe3C@graphene particles rather than carbon nanotube formation. The synthesized NPs were analyzed via different surface-sensitive techniques and magnetic measurement methods to determine their structural and magnetic properties. Our work provides a rapid and general procedure for core–shell Fe3C@graphene synthesis by using a CVD technique.

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“…The instability, large aggregation, and rapid bio-degradation of the pure uncoated (naked) magnetic nanoparticles could be overcome by replacement of the naked magnetic nanoparticles by the encapsulated ones [8]. Coating metallic cores by silica [9], carbon [10,11] and precious-metal [12] are examples of popular inorganic coating approaches. Although, to date, most studies have been focused on the development of polymer or silica protective coatings, recently carbon-coated magnetic nanoparticles are receiving more attention, because carbon-based materials have many advantages over polymer or silica, such as high chemical and thermal stability, better conductivity, as well as biocompatibility of carbon-based materials [13].…”

Section: Introductionmentioning

confidence: 99%

Size Control of Carbon Encapsulated Iron Nanoparticles by Arc Discharge Plasma Method

et al. 2016

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Size control of core@shell nanostructures is still a challenge. Carbon encapsulated iron nanoparticles (CEINPs) were synthesized by arc discharge plasma method in this study. CEINPs size can be controlled by varying gas composition, due to change in plasma properties. The morphology and structural features were investigated using scanning electron microscopy, transmission electron microscopy (TEM) and high-resolution TEM. Magnetic properties were studied to confirm the changes in CEINPs size by using superconducting quantum interference device. In order to evaluate the carbon shell protection and ensure the absence of iron oxide, selected area electron diffraction technique, energy-dispersive x-ray spectroscopy and electron energy loss spectroscopy were employed. Moreover, the degree of carbon order-disorder was studied by Raman Spectroscopy. It was concluded that arc discharge method is a suitable technique for precise size control of CEINPs.

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Synthesis and properties of modified graphite encapsulated iron metal nanoparticles

Cited by 8 publications

References 27 publications

Long-term live cells observation of internalized fluorescent Fe@C nanoparticles in constant magnetic field

Long-term live cells observation of internalized fluorescent Fe@C nanoparticles in constant magnetic field

Graphene-Assisted Magnetic Iron Carbide Nanoparticle Growth

Size Control of Carbon Encapsulated Iron Nanoparticles by Arc Discharge Plasma Method

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