scholarly journals 2D analysis of polydisperse core–shell nanoparticles using analytical ultracentrifugation

The Analyst ◽  
2017 ◽  
Vol 142 (1) ◽  
pp. 206-217 ◽  
Author(s):  
Johannes Walter ◽  
Gary Gorbet ◽  
Tugce Akdas ◽  
Doris Segets ◽  
Borries Demeler ◽  
...  
Keyword(s):  
Shell Structure ◽  
Analytical Ultracentrifugation ◽  
Accurate Determination ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles

A tool for the 2D analysis of polydisperse core–shell nanoparticles using analytical ultracentrifugation is presented. It allows for the accurate determination of sizes and densities of sub-10 nm particles, thereby revealing important information on their core–shell structure.

PREPARATION AND CHARACTERIZATION OF SURFACE-FUNCTIONALIZATION OF SILICA-COATED MAGNETITE NANOPARTICLES FOR DRUG DELIVERY

NANO ◽  
2014 ◽  
Vol 09 (04) ◽  
pp. 1450042 ◽  
Author(s):  
CONG-WANG ZHANG ◽  
CHANG-CHUN ZENG ◽  
YING XU
Keyword(s):  
Drug Delivery ◽  
Shell Structure ◽  
Drug Carrier ◽  
Point Of View ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Application Potential ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles

Fe 3 O 4– SiO 2 core–shell structure nanoparticles containing magnetic properties were investigated for their potential use in drug delivery. The Fe 3 O 4– SiO 2 core–shell structure nanoparticles were successfully synthesized by a simple and convenient way. The Fe 3 O 4– SiO 2 nanoparticles showed superparamagnetic behavior, indicating a great application potential in separation technologies. From the application point of view, the prepared nanoparticles were found to act as an efficient drug carrier. Specifically, the surface of the core–shell nanoparticles was modified with amino groups by use of silane coupling agent 3-aminopropyltriethoxysilane (APTS). Doxorubicin (DOX) was successfully grafted to the surface of the core–shell nanoparticles after the decoration with the carboxyl acid groups on the surface of amino-modified core–shell structure nanoparticles. Moreover, the nanocomposite showed a good drug delivery performance in the DOX-loading efficiency and drug release experiments, confirming that the materials had a great application potential in drug delivery. It is envisioned that the prepared materials are the ideal agent for application in medical diagnosis and therapy.

A BIO-INSPIRED POLYDOPAMINE APPROACH TO PREPARATION OF GOLD-COATED Fe3O4 CORE–SHELL NANOPARTICLES: SYNTHESIS, CHARACTERIZATION AND MECHANISM

NANO ◽  
2013 ◽  
Vol 08 (06) ◽  
pp. 1350061 ◽  
Author(s):  
PENG AN ◽  
FANG ZUO ◽  
XINHUA LI ◽  
YUANPENG WU ◽  
JUNHUA ZHANG ◽  
...  
Keyword(s):  
Shell Structure ◽  
Room Temperature ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Stabilizing Agent ◽  
X Ray ◽  
Transmission Electron ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles

A biomimetic and facile approach for integrating Fe 3 O 4 and Au with polydopamine (PDA) was proposed to construct gold-coated Fe 3 O 4 nanoparticles ( Fe 3 O 4@ Au – PDA ) with a core–shell structure by coupling in situ reduction with a seed-mediated method in aqueous solution at room temperature. The morphology, structure and composition of the core–shell structured Fe 3 O 4@ Au – PDA nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectrometry (XPS). The formation process of Au shell was assessed using a UV-Vis spectrophotometer. More importantly, according to investigating changes in PDA molecules by Fourier transform infrared spectroscopy (FTIR) and in preparation process of the zeta-potential data of nanoparticles, the mechanism of core–shell structure formation was proposed. Firstly, PDA-coated Fe 3 O 4 are obtained using dopamine (DA) self-polymerization to form thin and surface-adherent PDA films onto the surface of a Fe 3 O 4 "core". Then, Au seeds are attached on the surface of PDA-coated Fe 3 O 4 via electrostatic interaction in order to serve as nucleation centers catalyzing the reduction of Au 3+ to Au 0 by the catechol groups in PDA. Accompanied by the deposition of Au , PDA films transfer from the surface of Fe 3 O 4 to that of Au as stabilizing agent. In order to confirm the reasonableness of this mechanism, two verification experiments were conducted. The presence of PDA on the surface of Fe 3 O 4@ Au – PDA nanoparticles was confirmed by the finding that glycine or ethylenediamine could be grafted onto Fe 3 O 4@ Au – PDA nanoparticles through Schiff base reaction. In addition, Fe 3 O 4@ Au – DA nanoparticles, in which DA was substituted for PDA, were prepared using the same method as that for Fe 3 O 4@ Au – PDA nanoparticles and characterized by UV-Vis, TEM and FTIR. The results validated that DA possesses multiple functions of attaching Au seeds as well as acting as both reductant and stabilizing agent, the same functions as those of PDA.

Designed self-assembled hybrid Au@CdS core–shell nanoparticles with negative charge and their application as highly selective biosensors

2015 ◽  
Vol 3 (2) ◽  
pp. 217-224 ◽  
Author(s):  
Wuxiang Zhang ◽  
Jianzhong Zheng ◽  
Changhui Tan ◽  
Xuan Lin ◽  
Shirong Hu ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Shell Structure ◽  
Negative Charge ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Structure ◽  
Self Assembled ◽  
Core Shell Nanoparticles

Schematic illustration of the reaction mechanism of Au@CdS core–shell structure with DA in the presence of UA and AA.

Cationic fluorescent polymer core–shell nanoparticles for encapsulation, delivery, and non-invasively tracking the intracellular release of siRNA

2015 ◽  
Vol 51 (14) ◽  
pp. 2976-2979 ◽  
Author(s):  
Ji-Cheng Yu ◽  
Sha Zhu ◽  
Pei-Jian Feng ◽  
Cheng-Gen Qian ◽  
Jun Huang ◽  
...  
Keyword(s):  
Shell Structure ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Intracellular Release ◽  
Fluorescent Polymer ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles

Nanocarriers with core–shell structure for delivery and non-invasively tracking the intracellular release of siRNA are developed.

scholarly journals Efficient Color Tuning of Upconversion Luminescence from Core-Shell Oxysulfide Nanoparticles

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Ying Tian ◽  
Jianxin Jiao ◽  
Xin Feng ◽  
Mingming Xing ◽  
Yong Peng ◽  
...  
Keyword(s):  
Shell Structure ◽  
Upconversion Luminescence ◽  
Cross Relaxation ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Luminescence Efficiency ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles ◽  
Triple Ion

The Y2O2S:Er3+@Y2O2S:Yb3+,Ho3+ core-shell up-conversion (UC) nanoparticles were successfully synthesized by the homogeneous co-precipitation method. The Y2O2S:Er3+@Y2O2S:Yb3+,Ho3+ core-shell nanoparticles exhibit bright green emissions under 980 nm excitation, while the triple-ion doped Y2O2S:Er3+,Yb3+,Ho3+ sample presents mainly red emissions. The intensity ratio of green-to-red emission of the core-shell and conventional triple-ion doped samples are 2.8 and 0.3, respectively. Investigations on the UC mechanisms show that emissions from Er3+ and Ho3+ ions are achieved simultaneously in the core-shell nanoparticles. This is due to the efficient energy transfers of Yb3+→Ho3+ within the shell layer and Yb3+→Er3+ between the shell and the core. While the triple-ion doped Y2O2S: Er3+,Yb3+,Ho3+ sample exhibits mainly the emissions of Er3+ along with weak luminescence of Ho3+ ion. Since the cross relaxation between Er3+ and Ho3+ ions in the Y2O2S:Er3+,Yb3+,Ho3+ nanoparticles can effectively suppress the emissions of Ho3+ ions. Yet, in the core-shell structure, this cross relaxation can be successfully restrained in the core-shell structure where Er3+ is in the core and Ho3+ is in the shell. Therefore, the construction of core-shell structure can improve the luminescence efficiency and provide a route for adjustment of emission color.

scholarly journals Synthesis and Comparative Biological Properties of Ag-PEG Nanoparticles with Tunable Morphologies from Janus to Multi-Core Shell Structure

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1787 ◽  
Author(s):  
Mengda Xu ◽  
Jie Liu ◽  
Xiankui Xu ◽  
Shanhu Liu ◽  
František Peterka ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Silver Nitrate ◽  
Shell Structure ◽  
Irradiation Time ◽  
Antibacterial Activities ◽  
Biological Properties ◽  
Hybrid Nanoparticles ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Structure

Silver nanoparticles synthesized with polymers as coating agents is an effective method to overcome their poor stability and aggregation in solution. Silver-polyethylene glycol (Ag-PEG) nanoparticles were synthesized with the thiol-functionalized polyethylene glycol (SH-PEA) as the coating, reducing and stabilizing agent. The UV irradiation time, polymer and silver nitrate concentration for the synthesis were investigated. The concentration of silver nitrate had significant effect on the morphology of Ag-PEG nanoparticles. When increasing the concentration of silver nitrate, SEM and TEM images showed that Ag-PEG nanoparticles changed from Janus to multi-core shell structure. Meanwhile, pure silver particles in the two hybrid nanoparticles presented spherical shape and had the similar size of 15 nm. The antibacterial activities and cytotoxicity of the two structural Ag-PEG nanoparticles were investigated to understand colloid morphology effect on the properties of AgNPs. The results of antibacterial activities showed that the two structural Ag-PEG nanoparticles exhibited strong antibacterial activities against Staphylococcus aureus, Escherichia coli and Bacillus subtilis. The Janus nanoparticles had larger minimal inhibitory concentration (MIC) and minimum bacterial concentration (MBC) values than the multi-core shell counterparts. The results of cytotoxicity showed the Janus Ag-PEG nanoparticles had lower toxicity than the multi-core shell nanoparticles.

Colloidal Preparation of γ-Fe2O3@Au [core@shell] Nanoparticles

2003 ◽  
Vol 774 ◽  
Author(s):  
Jiye Fang ◽  
Jibao He ◽  
Eun Young Shin ◽  
Deborah Grimm ◽  
Charles J. O'Connor ◽  
...  
Keyword(s):  
Magnetic Core ◽  
Core Shell ◽  
Medical Systems ◽  
Solution Synthesis ◽  
Organic Solution ◽  
Shell Nanoparticles ◽  
The Core ◽  
Promising Application ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles

Abstractγ-Fe2O3@Au core-shell nanoparticles were prepared through a combined route, in which high temperature organic solution synthesis and colloidal microemulsion techniques were successively applied. High magnification of TEM reveals the core-shell structure. The presence of Au on the surface of as-prepared particles is also confirmed by UV-Vis absorption. The magnetic core-shell nanoparticles offer a promising application in bio- and medical systems.

Application of the apparent lattice parameter to determination of the core-shell structure of nanocrystals

2007 ◽  
Vol 222 (11/2007) ◽  
Author(s):  
Bogdan Palosz ◽  
Svetlana Stelmakh ◽  
Ewa Grzanka ◽  
Stanislaw Gierlotka ◽  
Witold Palosz
Keyword(s):  
Shell Model ◽  
Shell Structure ◽  
Lattice Parameter ◽  
Core Shell ◽  
Bragg Scattering ◽  
The Core ◽  
Core Shell Structure

In this review work we discuss applicability of Bragg scattering to examination of nanocrystals. We approximate the structure of nanograins by a commonly accepted core-shell model. We show that, for principal reasons, the Bragg equation is not applicable directly to nanocrystals. We use the Bragg relation through application of the

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