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

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.

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Monodisperse Fe3O4/Fe Core/Shell Nanoparticles with Enhanced Magnetic Property

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.410 ◽

2011 ◽

Vol 306-307 ◽

pp. 410-415

Author(s):

Li Sun ◽

Fu Tian Liu ◽

Qi Hui Jiang ◽

Xiu Xiu Chen ◽

Ping Yang

Keyword(s):

Average Diameter ◽

Chemical Precipitation ◽

Precipitation Method ◽

Core Shell ◽

X Ray Diffraction ◽

Shell Nanoparticles ◽

X Ray ◽

Transmission Electron ◽

Shell Particles ◽

Core Shell Nanoparticles

Core/shell type nanoparticles with an average diameter of 20nm were synthesized by chemical precipitation method. Firstly, Monodisperse Fe3O4 nanoparticles were synthesized by solvethermal method. FeSO47H2O and NaBH4 were respectively dissolved in distilled water, then moderated Fe3O4 particles and surfactant(PVP) were ultrasonic dispersed into the FeSO47H2O solution. The resulting solution was stirred 2 h at room temperature. Fe could be deposited on the surface of monodispersed Fe3O4 nanoparticles to form core-shell particles. The particles were characterized by using various experimental techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), AGM and DTA. The results suggest that the saturation magnetization of the nanocomposites is 100 emu/g. The composition of the samples show monodisperse and the sides of the core/shell nanoparticles are 20-30nm. It is noted that the formation of Fe3O4/Fe nanocomposites magnetite nanoparticles possess superparamagnetic property.

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

NANO ◽

10.1142/s1793292014500428 ◽

2014 ◽

Vol 09 (04) ◽

pp. 1450042 ◽

Cited By ~ 12

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.

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The Preparation and Characteristic of Superparamagnetic Core/Shell Nanoparticles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.274.432 ◽

2013 ◽

Vol 274 ◽

pp. 432-435

Author(s):

Hong Xia Shen ◽

Zheng Zhi Yin ◽

Qiong Cheng

Keyword(s):

Biomedical Applications ◽

Superparamagnetic Nanoparticles ◽

Bioactive Molecules ◽

Core Shell ◽

Shell Nanoparticles ◽

X Ray ◽

Transmission Electron ◽

Vibration Sample Magnetometer ◽

Diffraction Patterns ◽

Core Shell Nanoparticles

Superparamagnetic core/shell nanoparticles have been prepared successfully by the reduction of Au3+ onto the surface of superparamagnetic nanoparticles. The core/shell nanoparticles were characterized by Transmission electron microscopy (TEM), X-ray powder diffraction patterns (XRD), UV–vis spectrophotometer, Vibration Sample Magnetometer(VSM) and micro-confocal Raman system. The results revealed that the prepared core/shell nanoparticles were covered by Au shell. These superparamagnetic nanoparticles can be highly sensitively detected and afford new opportunities for biomedical applications through chemical bonding of bioactive molecules with the Au shell of nanoparticles.

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Synthesis and Characterization of Fe/Nd2O3 Core–Shell Nanoparticles by Hydrogen Plasma-Metal Reaction

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2006.17945 ◽

2006 ◽

Vol 6 (3) ◽

pp. 743-747 ◽

Cited By ~ 2

Author(s):

Tong Liu ◽

Shicheng Zhang ◽

Xingguo Li

Keyword(s):

Hydrogen Plasma ◽

Core Shell ◽

Shell Nanoparticles ◽

X Ray ◽

Nanoparticle Surface ◽

Transmission Electron ◽

Potential Applications ◽

Catalytic Fields ◽

Core Shell Nanoparticles

Fe/Nd2O3 core–shell nanoparticles (CSNs) with a mean diameter of 35 nm were produced successfully by using hydrogen plasma-metal reaction (HPMR) method. This core–shell structure was confirmed by high resolution transmission electron microscopy (HRTEM), energy dispersion X-ray spectroscopy (EDS), X-ray photoelectron spectral (XPS), and induction-coupled plasma (ICP) spectroscopy. The magnetic properties were measured by vibrating sample magnetometer (VSM). It was found that the mole ratio of Nd to Fe on the nanoparticle surface is 1.2:1, about 7 times of that of the whole nanoparticle. The saturation magnetization Ms and remanence Mr of Fe/Nd2O3 nanoparticles decrease prominently from Fe nanoparticles, whereas the coercivity HC drops only less than 5% of Fe nanoparticle. These CSNs have potential applications in magnetic and catalytic fields.

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Effect of protamine on Fe3O4@CS@GFTN composite magnetic nanoparticles

Functional Materials Letters ◽

10.1142/s1793604720500010 ◽

2019 ◽

Vol 13 (02) ◽

pp. 2050001 ◽

Cited By ~ 1

Author(s):

Huiping Shao ◽

Luhui Wang ◽

Tao Lin ◽

Yumeng Zhang ◽

Zhinan Zhang

Keyword(s):

Magnetic Nanoparticles ◽

Shell Structure ◽

Lung Diseases ◽

Core Shell ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Core Shell Structure ◽

Average Size ◽

Chemical Coprecipitation Method

Fe3O4@chitosan (CS)@Gefitinib (GFTN) core-shell structure composite magnetic nanoparticles (NPs) were prepared by chemical coprecipitation method in this study. In addition, protamine was doped in Fe3O4 cores to prepare Fe3O4@protamine@CS@GFTN core-shell structure composite NPs, in order to increase the loading of GFTN in composite NPs. They were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and spectrophotometer. The results show that the average size of Fe3O4@CS@GFTN and Fe3O4@protamine@CS@GFTN composite NPs is approximately 19 and 21[Formula: see text]nm, respectively. The saturation magnetizations of composite magnetic NPs and corresponding magnetic fluids are 57.20, 20.79, 59.58 and 19.75[Formula: see text]emu/g, respectively. The loading of GFTN in composite NPs was measured by a spectrophotometer to be about 13.5% and 27.6%, respectively. The addition of protamine increased the loading of GFTN two times, indicating that it will play an important role in the management of lung diseases.

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In situ TEM observation of Au–Cu2O core–shell growth in liquids

Nanoscale ◽

10.1039/c9nr00972h ◽

2019 ◽

Vol 11 (21) ◽

pp. 10486-10492 ◽

Cited By ~ 5

Author(s):

Fu-Chun Chen ◽

Jui-Yuan Chen ◽

Ya-Hsuan Lin ◽

Ming-Yu Kuo ◽

Yung-Jung Hsu ◽

...

Keyword(s):

Electron Microscopy ◽

Shell Growth ◽

Core Shell ◽

In Situ Tem ◽

Shell Nanoparticles ◽

Transmission Electron ◽

Liquid Cell ◽

Different Shapes ◽

Core Shell Nanoparticles

The formation of different shapes Au–Cu2O core–shell nanoparticles was investigated by in situ liquid cell transmission electron microscopy (LCTEM).

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Luminescence Nanothermometry Based on Pr3+ : LaF3 Single Core and Pr3+ : LaF3/LaF3 Core/Shell Nanoparticles

Advances in Materials Science and Engineering ◽

10.1155/2019/2618307 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

M. S. Pudovkin ◽

D. A. Koryakovtseva ◽

E. V. Lukinova ◽

S. L. Korableva ◽

R. Sh. Khusnutdinova ◽

...

Keyword(s):

Coherent Scattering ◽

Core Shell ◽

Fluorescence Intensity Ratio ◽

X Ray Diffraction ◽

Shell Nanoparticles ◽

X Ray ◽

The Core ◽

Transmission Electron ◽

Means Of Transmission ◽

Core Shell Nanoparticles

Core Pr3+ : LaF3 (CPr = 1%) plate-like nanoparticles (nanoplates), core/shell Pr3+ : LaF3 (CPr = 1%)/LaF3 nanoplates, core Pr3+ : LaF3 (CPr = 1%) sphere-like nanoparticles (nanospheres), and core/shell Pr3+ : LaF3 (CPr = 1%)/LaF3 nanospheres were synthesized via the coprecipitation method of synthesis. The nanoparticles (NPs) were characterized by means of transmission electron microscopy, X-ray diffraction, and optical spectroscopy. The formation of the shell was proved by detecting the increase in physical sizes, sizes of coherent scattering regions, and luminescence lifetimes of core/shell NPs comparing with single core NPs. The average physical sizes of core nanoplates, core/shell nanoplates, core nanospheres, and core/shell nanospheres were 62.2 ± 0.9, 74.7 ± 1.2, 13.8 ± 0.9 and 22.0 ± 1.2 nm, respectively. The formation of the NP shell led to increasing of effective luminescence lifetime τeff of the 3P0 state of Pr3+ ions for the core nanoplates, core/shell nanoplates, core nanospheres, and core/shell nanospheres the values of τeff were 2.3, 3.6, 3.2, and 4.7 μsec, respectively (at 300 K). The values of absolute sensitivity Sa for fluorescence intensity ratio (FIR) thermometry was 0.01 K−1 at 300 K for all the samples. The FIR sensitivity can be attributed to the fact that 3P1 and 3P0 states share their electronic populations according to the Boltzmann process. The values of Sa for lifetime thermometry for core nanoplates, core/shell nanoplates, core nanospheres, and core/shell nanospheres were (36.4 ± 3.1) · 10−4, (70.7 ± 5.9) · 10−4, (40.7 ± 2.6) · 10−4, and (68.8 ± 2.4) · 10−4 K−1, respectively.

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