Fe3O4@SiO2 core–shell nanoparticles for biomedical purposes: adverse effects on blood cells

2016 ◽  
Vol 4 (10) ◽  
pp. 1417-1421 ◽  
Author(s):  
C. Achilli ◽  
S. Grandi ◽  
G. F. Guidetti ◽  
A. Ciana ◽  
C. Tomasi ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Magnetite Nanoparticles ◽  
Reverse Micelle ◽  
Blood Cells ◽  
Sol Gel ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Sol Gel Process ◽  
Core Shell Nanoparticles

Magnetite nanoparticles coated with silica, obtained by a sol–gel process in the reverse micelle microemulsion, were characterized and homogeneously suspended in water in order to assay their biocompatibility toward blood cells, in view of a potential medical use of this material.

Structure and Luminescence of Europium-Doped Gadolinia-Based Core/Multi-Shell Scintillation Nanoparticles

2009 ◽  
Vol 1164 ◽  
Author(s):  
Teng-Kuan Tseng ◽  
Jihun Choi ◽  
Paul H. Holloway
Keyword(s):  
Charge Transfer Band ◽  
Sol Gel ◽  
Core Shell ◽  
Photoluminescence Excitation ◽  
Shell Nanoparticles ◽  
Direct Excitation ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Pl Emission ◽  
Core Shell Nanoparticles

AbstractScintillating nanoparticles with a SiO2 core and a Gd2O3 shell doped with Eu3+ were synthesized with a sol-gel process. Based on transmission electron microscopy (TEM) data, a ∼13 nm Gd2O3 shell was successfully coated onto ∼220 nm mono-dispersed SiO2 nanocores. Eu3+ ions at concentrations of nominally 5 at% exhibited photoluminescent (PL) emission from the SiO2/Gd2O3 nanoparticles after being calcined at 800 0C for 2 h. The SiO2 remained amorphous after calcining, while the Gd2O3 crystallized to a cubic structure. The PL emission was from the 5D0-7F2 transitions of Eu3+ at 609 and 622 nm. Photoluminescence excitation (PLE) data showed that emission from Eu3+ could result from direct excitation, but was dominated by the oxygen to europium charge-transfer band (CTB) between 250 and 280 nm for Eu3+ doped in Gd2O3. The quantum yield (QY) from thin films drop cast from a mixture of 20 mg of calcined nanoparticles in 500 μL of polymethylmethacrylate (PMMA) and excited in the CTB was 20% for SiO2/Gd2O3:Eu3+ core/shell scintillation nanoparticles. Finally, the above core/shell nanoparticles were passivated with a shell of SiO2 to create e.g. SiO2/Gd2O3:Eu3+/SiO2 nanoparticles. The QYs for this nanostructure were lower than unpassivated nanoparticles which was attributed to a weak CTB for the amorphous SiO2 shell and a higher density of interface quenching sites.

scholarly journals PREPARATION OF CORE-SHELL SILVER/SILICA NANOPATICLES AND THEIR APPLICATION FOR ENHANCEMENT OF CYANINE 3 FLUORESCENCE

2012 ◽  
Vol 11 (04) ◽  
pp. 1240020 ◽  
Author(s):  
N. SUI ◽  
V. MONNIER ◽  
Z. YANG ◽  
Y. CHEVOLOT ◽  
E. LAURENCEAU ◽  
...  
Keyword(s):  
Steady State ◽  
Fluorescence Spectroscopy ◽  
Sol Gel ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Steady State Fluorescence ◽  
Covalently Bonded ◽  
Core Shell Nanoparticles ◽  
Steady State Fluorescence Spectroscopy ◽  
Silver Core

Core shell Ag@SiO2 -Streptavidin- Cy3 nanoparticles were prepared. Ag@SiO2 nanoparticles were synthesized via a sol–gel method. Then, Streptavidin- Cy3 was covalently bonded to the Ag@SiO2 surface. These core-shell nanoparticles were characterized by steady-state fluorescence spectroscopy and fluorescence scanning. In presence of the silver core, a 2.5-time enhancement of Cy3 fluorescence intensity was obtained. This result shows that these nanoparticles can be potentially helpful in surface analysis based on biochip.

Synthesis and Magnetic Properties of FePt Nanoparticles with Hard Nonmagnetic Shells

2007 ◽  
Vol 7 (1) ◽  
pp. 350-355 ◽  
Author(s):  
Shishou Kang ◽  
Shifan Shi ◽  
G. X. Miao ◽  
Zhiyong Jia ◽  
David E. Nikles ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystallographic Orientation ◽  
Sol Gel ◽  
Molar Ratio ◽  
Core Shell ◽  
Fept Nanoparticles ◽  
Shell Nanoparticles ◽  
Spherical Core ◽  
Size And Morphology ◽  
Core Shell Nanoparticles

Chemically synthesized FePt nanoparticles were coated with nonmagnetic SiO2 and MnO shells by sol–gel and polyol processes. TEM images show that the FePt/SiO2 nanoparticles exhibit a thick spherical shell. The size and morphology of the MnO shell can be controlled by changing the reaction temperature, the molar ratio of surfactants/Mn(acac)2, and/or the concentration of precursor. The morphology of the MnO shell can be either spherical-like or cubic-like, depending on whether the molar ratio of surfactants/Mn(acac)2 is less than or larger than 2. From XRD measurements, the spherical core/shell nanoparticles exhibit 3D random crystallographic orientation, while the cubic core/shell nanoparticles prefer (200) texture. The magnetic moment of FePt particles can be enhanced by coating with SiO2 and MnO shells. Furthermore, the agglomeration of FePt particles upon the thermal annealing can be significantly inhibited with SiO2 and MnO shells.

Physico-Chemical Properties of Silica Coated Superparamagnetic Magnetite Nanoparticles Synthesized by Non-Seeded Process

2015 ◽  
Vol 1107 ◽  
pp. 267-271
Author(s):  
Sodipo Bashiru Kayode ◽  
Azlan Abdul Aziz
Keyword(s):  
Silica Nanoparticles ◽  
Magnetite Nanoparticles ◽  
Colloidal Suspension ◽  
Sol Gel ◽  
Chemical Properties ◽  
Colloidal Suspensions ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Physico Chemical ◽  
Physical And Chemical

The science of core-shell nanoparticles requires investigation into several physical and chemical properties of the composite nanoparticles. Unlike the conventional sol-gel or the reverse microemulsion micelle method, we presented here a non-seeded process of encapsulating superparamagnetic magnetite nanoparticles (SPMN) with silica. Physico-chemical analysis of the product was used to confirm the result of the coating procedure. Colloidal suspension of SPMN and silica nanoparticles were synthesised through coprecipitation method and modified Stöber method respectively. Afterwards, both colloidal suspensions of SPMN and silica nanoparticles were sonicated to encapsulate the SPMN with silica. Elemental mapping of the composite particles with electron spectroscopy imaging (ESI) confirmed the core-shell micrograph of the SPMN and silica. The X-ray diffraction pattern (XRD) showed the silica shell to be in amorphous form. FTIR analysis further confirmed the chemical properties of the product to be silica coated SPMN.

Preparation and characterization of sol–gel derived Er3+–Yb3+ codoped SiO2/TiO2 core–shell nanoparticles

2010 ◽  
Vol 64 (7) ◽  
pp. 846-848 ◽  
Author(s):  
Shujie Pang ◽  
Xianliang Li ◽  
Zuosen Shi ◽  
Guang Yang ◽  
Zhanchen Cui
Keyword(s):  
Sol Gel ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

scholarly journals Fabrication of Magnetite/Silica/Titania Core-Shell Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Suh Cem Pang ◽  
Sze Yun Kho ◽  
Suk Fun Chin
Keyword(s):  
Methylene Blue ◽  
Uv Light ◽  
Sol Gel ◽  
Core Shell ◽  
Silica Nanospheres ◽  
Shell Nanoparticles ◽  
Gel Method ◽  
Uv Light Irradiation ◽  
Silica Nanosphere ◽  
Core Shell Nanoparticles

Fe3O4/SiO2/TiO2core-shell nanoparticles were synthesized via a sol-gel method with the aid of sonication. Fe3O4nanoparticles were being encapsulated within discrete silica nanospheres, and a layer of TiO2shell was then coated directly onto each silica nanosphere. As-synthesized Fe3O4/SiO2/TiO2core-shell nanoparticles showed enhanced photocatalytic properties as evidenced by the enhanced photodegradation of methylene blue under UV light irradiation.

scholarly journals Preparation and Characterization of Magnetite – Silica Core – Shell Nanoparticles

2021 ◽  
Vol 15 ◽  
pp. 1457-1463
Author(s):  
S. N. Vakhneev ◽  
Minggong Sha
Keyword(s):  
Magnetite Nanoparticles ◽  
Biomedical Applications ◽  
Core Shell ◽  
Amino Groups ◽  
Absorption Bands ◽  
Shell Nanoparticles ◽  
Oh Groups ◽  
Silica Core ◽  
Core Shell Nanoparticles

In this study, two types of ligands were introduced onto the surface of magnetite nanoparticles by hydrolysis and condensation of organosilicon reagents: organosilane-tetraethoxysilane (TEOS) and aminoorganosilane - aminopropyltriethoxysilane (APTES). It is shown that coatings based on SiO2 solve a double problem: first, they prevent the aggregation of nanoparticles and the oxidation of magnetite; secondly, they allow the surface to be modified with various specific ligands for biomedical applications due to terminal groups. It was shown, that after the modification of TEOS and APTES (in argon and in air), the Fe3O4 content decreases to 66, 42, and 36%, respectively. The formation of a silicon framework on the magnetite surface due to Fe-O-Si and Si-O-Si bonds was determined by IR spectroscopy. The identification of surface amino groups is complicated due to the superposition of absorption bands of NH2- and OH-groups. This opens new prospective for creation of tailored nanocomposites containing magnetite nanoparticles. These materials can be further used as sorbents for various applications.

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