EPR spectroscopy and imaging of TEMPO-labeled magnetite nanoparticles

Krzyminiewski, Ryszard; Kubiak, Tomasz; Dobosz, Bernadeta; Schroeder, Grzegorz; Kurczewska, Joanna

doi:10.1016/j.cap.2014.03.021

Cited by 23 publications

(19 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All samples revealed two signals, with the first obtained in a low magnetic field with different g factor values and a second peak collected in a high magnetic field with similar g factor values (Supplementary Table S3 ). The ESR signal in all samples had the same curve shape with a single g factor value, reflecting the superparamagnetic properties of a sample, as shown in previous studies (Supplementary Figure S4 ) ( Krzyminiewski et al, 2014 ; Dobosz et al, 2016 ). Differences in the sizes and shapes and the presence of peptides in the samples can affect the width and introduce some small variety in the g values measured.…”

Section: Resultssupporting

confidence: 80%

Understanding the Biomineralization Role of Magnetite-Interacting Components (MICs) From Magnetotactic Bacteria

et al. 2018

View full text Add to dashboard Cite

Biomineralization is a process that takes place in all domains of life and which usually helps organisms to harden soft tissues by creating inorganic structures that facilitate their biological functions. It was shown that biominerals are under tight biological control via proteins that are involved in nucleation initiation and/or which act as structural skeletons. Magnetotactic bacteria (MTB) use iron biomineralization to create nano-magnetic particles in a specialized organelle, the magnetosome, to align to the geomagnetic field. A specific set of magnetite-associated proteins (MAPs) is involved in regulating magnetite nucleation, size, and shape. These MAPs are all predicted to contain specific 17–22 residue-long sequences involved in magnetite formation. To understand the mechanism of magnetite formation, we focused on three different MAPs, MamC, Mms6 and Mms7, and studied the predicted iron-binding sequences. Using nuclear magnetic resonance (NMR), we differentiated the recognition mode of each MAP based on ion specificity, affinity, and binding residues. The significance of critical residues in each peptide was evaluated by mutation followed by an iron co-precipitation assay. Among the peptides, MamC showed weak ion binding but created the most significant effect in enhancing magnetite particle size, indicating the potency in controlling magnetite particle shape and size. Alternatively, Mms6 and Mms7 had strong binding affinities but less effect in modulating magnetite particle size, representing their major role potentially in initiating nucleation by increasing local metal concentration. Overall, our results explain how different MAPs affect magnetite synthesis, interact with Fe2+ ions and which residues are important for the MAPs functions.

show abstract

Section: Resultssupporting

confidence: 80%

Understanding the Biomineralization Role of Magnetite-Interacting Components (MICs) From Magnetotactic Bacteria

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Indeed, the features of the spectra are also typical of cubic magnetocrystalline anisotropy in solids such as magnetite. In accordance with the literature reports, the spectra display the typical cubic magnetocrystalline anisotropy for magnetite-based solids [42,43].…”

Section: Materials 2020 13 X For Peer Review 12 Of 24supporting

confidence: 91%

“…The lowest signal at around 4700 Oe depicts g = 4.0 suggesting the paramagnetic resonance of isolated Fe 3+ with rhombic symmetry, in which the ions are located in tetrahedral FeO 4 and/or octahedral FeO 6 local and Fe 2+ species [40][41][42]. It is important to note that the EPR spectra line shapes of the Fe/FeC and FeC composites are strikingly similar with narrow signals, compared to that of Fe sample.…”

Section: Materials 2020 13 X For Peer Review 12 Of 24mentioning

confidence: 89%

Acid Red 66 Dye Removal from Aqueous Solution by Fe/C-based Composites: Adsorption, Kinetics and Thermodynamic Studies

et al. 2020

View full text Add to dashboard Cite

The presence of synthetic dyes in water causes serious environmental issues owing to the low water quality, toxicity to environment and human carcinogenic effects. Adsorption has emerged as simple and environmental benign processes for wastewater treatment. This work reports the use of porous Fe-based composites as adsorbents for Acid Red 66 dye removal in an aqueous solution. The porous FeC and Fe/FeC solids were prepared by hydrothermal methods using iron sulfates and sucrose as precursors. The physicochemical properties of the solids were evaluated through X-ray diffraction (XRD), Scanning electron microscopy coupled with Energy dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared s (FTIR), Raman and Mössbauer spectroscopies, nitrogen adsorption–desorption isotherms, Electron Paramagnetic Resonance (EPR) and magnetic saturation techniques. Results indicated that the Fe species holds magnetic properties and formed well dispersed Fe3O4 nanoparticles on a carbon layer in FeC nanocomposite. Adding iron to the previous solid resulted in the formation of γ-Fe2O3 coating on the FeC type structure as in Fe/FeC composite. The highest dye adsorption capacity was 15.5 mg·g−1 for FeC nanocomposite at 25 °C with the isotherms fitting well with the Langmuir model. The removal efficiency of 98.4% was obtained with a pristine Fe sample under similar experimental conditions.

show abstract

“…4), which are similar to superparamagnetism characteristic of magnetite nanoparticles. 43,44 with a coordination number of 3.4-4.3, and an equatorial nitrogen path at the U-N distance of 2.34 ± 0.04 Å with a coordination number of 1.6-0.7. The equatorial coordination environment of this U species consists of about 5 light scattering atoms, which was first obtained through the U-O eq path fitting and then was set to five in the subsequent fittings.…”

Section: Ftir and Epr Resultsmentioning

confidence: 99%

Sequestration of U(VI) from Acidic, Alkaline, and High Ionic-Strength Aqueous Media by Functionalized Magnetic Mesoporous Silica Nanoparticles: Capacity and Binding Mechanisms

Egodawatte

Kaplan

et al. 2017

Environ. Sci. Technol.

View full text Add to dashboard Cite

Uranium(VI) exhibits little adsorption onto sediment minerals in acidic, alkaline or high ionic-strength aqueous media that often occur in U mining or contaminated sites, which makes U(VI) very mobile and difficult to sequester. In this work, magnetic mesoporous silica nanoparticles (MMSNs) were functionalized with several organic ligands. The functionalized MMSNs were highly effective and had large binding capacity for U sequestration from high salt water (HSW) simulant (54 mg U/g sorbent). The functionalized MMSNs, after U exposure in HSW simulant, pH 3.5 and 9.6 artificial groundwater (AGW), were characterized by a host of spectroscopic methods. Among the key novel findings in this work was that in the HSW simulant or high pH AGW, the dominant U species bound to the functionalized MMSNs were uranyl or uranyl hydroxide, rather than uranyl carbonates as expected. The surface functional groups appear to be out-competing the carbonate ligands associated with the aqueous U species. The uranyl-like species were bound with N ligand as η bound motifs or phosphonate ligand as a monodentate, as well as on tetrahedral Si sites as an edge-sharing bidentate. The N and phosphonate ligand-functionalized MMSNs hold promise as effective sorbents for sequestering U from acidic, alkaline or high ionic-strength contaminated aqueous media.

show abstract

EPR spectroscopy and imaging of TEMPO-labeled magnetite nanoparticles

Cited by 23 publications

References 22 publications

Understanding the Biomineralization Role of Magnetite-Interacting Components (MICs) From Magnetotactic Bacteria

Understanding the Biomineralization Role of Magnetite-Interacting Components (MICs) From Magnetotactic Bacteria

Acid Red 66 Dye Removal from Aqueous Solution by Fe/C-based Composites: Adsorption, Kinetics and Thermodynamic Studies

Sequestration of U(VI) from Acidic, Alkaline, and High Ionic-Strength Aqueous Media by Functionalized Magnetic Mesoporous Silica Nanoparticles: Capacity and Binding Mechanisms

Contact Info

Product

Resources

About