Synthesis and functionalization of magnetite nanoparticles with different amino-functional alkoxysilanes

Bini, Rafael A.; Marques, Rodrigo Fernando Costa; Santos, Francisco José dos; Chaker, Juliano Alexandre; Jafelicci, Miguel

doi:10.1016/j.jmmm.2011.08.035

Cited by 233 publications

(153 citation statements)

References 21 publications

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“…The unfunctionalized MNPs showed Fe-O characteristic absorption band at 634.4 and 557.5 cm −1 [48]. Two other bands around 3422.7 cm −1 and 1634.9 cm −1 correspond to stretching and bending vibrations of surface hydroxyl groups on surface of MNPs [49].…”

Section: Discussionmentioning

confidence: 97%

Effect of Surface Charge and Hydrophobicity Modulation on the Antibacterial and Antibiofilm Potential of Magnetic Iron Nanoparticles

Shebl

Farouk

Azzazy

2017

Journal of Nanomaterials

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Unmodified magnetic nanoparticles (MNPs) lack antibacterial potential. We investigated MNPs surface modifications that can impart antibacterial activity. Six MNPs species were prepared and characterized. Their antibacterial and antibiofilm potentials, surface affinity, and cytotoxicity were evaluated. Prepared MNPs were functionalized with citric acid, amine group, amino-propyl trimethoxy silane (APTMS), arginine, or oleic acid (OA) to give hydrophilic and hydrophobic MNPs with surface charge ranging from −30 to +30 mV. Prepared MNPs were spherical in shape with an average size of 6-15 nm. Hydrophobic (OA-MNPs) and positively charged MNPs (APTMS-MNPs) had significant concentration dependent antibacterial effect. OA-MNPs showed higher inhibitory potential against S. aureus and E. coli (80%) than APTMS-MNPs (70%). Both particles exhibited surface affinity to S. aureus and E. coli. Different concentrations of OA-MNPs decreased S. aureus and E. coli biofilm formation by 50-90%, while APTMS-MNPs reduced it by 30-90%, respectively. Up to 90% of preformed biofilms of S. aureus and E. coli were destroyed by OAMNPs and APTMS-MNPs. In conclusion, surface positivity and hydrophobicity enhance antibacterial and antibiofilm properties of MNPs.

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Section: Discussionmentioning

confidence: 97%

Effect of Surface Charge and Hydrophobicity Modulation on the Antibacterial and Antibiofilm Potential of Magnetic Iron Nanoparticles

Shebl

Farouk

Azzazy

2017

Journal of Nanomaterials

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“…36 Currently, alcoholic or aqueous-alcoholic mediums are most frequently used for the immobilization of APS derivatives on the MNPs. 21,22 Consequently, the anchoring of polysiloxane on the surface of MNPs due to Si-O-Fe bond formation occurs. The MNPs applied in this research had hydrophilic properties; therefore, their modification with APTMS was carried out in aqueous-alcoholic solution similarly to the previously …”

Section: Synthesis Functionalization and Characterization Of The Prmentioning

confidence: 99%

“…[17][18][19] One of the most effective methods of modification is the covalent modification of MNP surface using various alkoxysilane reagents. 20 Alkoxysilanes are commercially available reagents that contain various functional groups such as amino, [21][22][23][24][25][26][27][28] mercapto, [26][27][28][29] glycidyloxy, 26,30,31 cyano, 27,32 carboxylic, aldehyde, and isocyanate 27 groups. Following the modification, alkoxysilanes form a cross-linked silicone layer with functional groups covering the surface of nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

3-Aminopropylsilane-modified iron oxide nanoparticles for contrast-enhanced magnetic resonance imaging of liver lesions induced by <em>Opisthorchis felineus</em>

Demin¹,

Pershina²,

Ivanov³

et al. 2016

IJN

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Purpose Liver fluke causes severe liver damage in an infected human. However, the infection often remains neglected due to the lack of pathognomonic signs. Nanoparticle-enhanced magnetic resonance imaging (MRI) offers a promising technique for detecting liver lesions induced by parasites. Materials and methods Surface modification of iron oxide nanoparticles produced by coprecipitation from a solution of Fe 3+ and Fe 2+ salts using 3-aminopropylsilane (APS) was carried out. The APS-modified nanoparticles were characterized by transmission electron microscopy, fourier transform infrared spectroscopy, and thermogravimetric analysis. Magnetic resonance properties of MNPs were investigated in vitro and in vivo. Results The amount of APS grafted on the surface of nanoparticles (0.60±0.06 mmol g −1 ) was calculated based on elemental analysis and infrared spectroscopy data. According to transmission electron microscopy data, there were no essential changes in the structure of nanoparticles during the modification. The APS-modified nanoparticles exhibit high magnetic properties; the calculated relaxivity r 2 was 271 mmol −1 s −1 . To obtain suspension with optimal hydrodynamic characteristics, amino groups on the surface of nanoparticles were converted into an ionic form with HCl. Cellular uptake of modified nanoparticles by rat hepatoma cells and human monocytes in vitro was 74.1±4.5 and 10.0±3.7 pg [Fe] per cell, respectively. Low cytotoxicity of the nanoparticles was confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Annexin V/7-aminoactinomycin D flow cytometry assays. For the first time, magnetic nanoparticles were applied for contrast-enhanced MRI of liver lesions induced by Opisthorchis felineus . Conclusion The synthesized APS-modified iron oxide nanoparticles showed high efficiency as an MRI contrast agent for the evaluation of opisthorchiasis-related liver damage.

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“…EDS analysis of calcite indicated 48.1% carbon, 39.5% oxygen and 12.4% calcium, whereas magnetosome coupled calcite showed 1.6% iron which confirms the coupling of calcite and magnetosomes. 19 FTIR analysis of magnetosomes, calcite and magnetic calcite showed the absorption peaks from 500 to 4000 cm −1 (Fig. 3).…”

Section: Resultsmentioning

confidence: 97%

Removal of Cr (III) and Ni (II) from tannery effluent using calcium carbonate coated bacterial magnetosomes

et al. 2018

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Heavy metal contamination of surface water bodies and ground water has been a major problem around the world. Calcium-based adsorbents are effective but cannot be separated easily after the treatment. Magnetosomes are biogenic magnetite synthesised as highly ordered chain-like structures by magnetotactic bacteria. In this study, we have prepared magnetically controlled calcite microcrystals using magnetosomes for the adsorption experiment. The ability of magnetic calcite as adsorbent was investigated for the removal of Cr (III) and Ni (II) ions from synthetic solution. Critical parameters, such as the effect of pH, temperature, contact time, initial ion concentration, and adsorbent dose, were optimised in comparison with calcite, magnetosomes, and activated carbon for maximum metal ion removal. The study showed that equilibrium was established in 1 h for both Cr (III) and Ni (II) at a pH of 6.0 and 8.0, respectively. The adsorption process follows pseudo-second-order reaction kinetics, along with Langmuir and Freundlich adsorption isotherms. The thermodynamics of adsorption of both metal ions on magnetic calcite showed that the adsorption was spontaneous and endothermic in nature. Magnetically controlled calcite crystals successfully removed Cr (III) and Ni (II) from collected tannery effluent and separated from the solution by applying magnetic field. Maximum removal of chromium and nickel (94 and 84%) by magnetic calcite is similar to calcite crystals but higher than magnetosomes and activated carbon. The results indicated that magnetic calcite could be used as an alternative adsorbent for removing heavy metals from tannery effluent.

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Synthesis and functionalization of magnetite nanoparticles with different amino-functional alkoxysilanes

Cited by 233 publications

References 21 publications

Effect of Surface Charge and Hydrophobicity Modulation on the Antibacterial and Antibiofilm Potential of Magnetic Iron Nanoparticles

Effect of Surface Charge and Hydrophobicity Modulation on the Antibacterial and Antibiofilm Potential of Magnetic Iron Nanoparticles

3-Aminopropylsilane-modified iron oxide nanoparticles for contrast-enhanced magnetic resonance imaging of liver lesions induced by <em>Opisthorchis felineus</em>

Removal of Cr (III) and Ni (II) from tannery effluent using calcium carbonate coated bacterial magnetosomes

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