A novel Co@Au structure formed in bimetallic core@shell nanoparticles

2015 ◽  
Vol 51 (40) ◽  
pp. 8442-8445 ◽  
Author(s):  
Alvaro Mayoral ◽  
Daniel Llamosa ◽  
Yves Huttel

A new type of core–shell Co@Au nanoparticles is reported here, where the core is formed by a Co icosahedron surrounded by fcc Au facets.

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Feng Liu ◽  
Honghua Huang ◽  
Ying Zhang ◽  
Ting Yu ◽  
Cailei Yuan ◽  
...  

The shell thickness-dependent strain distributions of the Au/Ag and Ag/Au core-shell nanoparticles embedded in Al2O3matrix have been investigated by finite element method (FEM) calculations, respectively. The simulation results clearly indicate that there is a substantial strain applied on both the Au/Ag and Ag/Au core-shell nanoparticles by the Al2O3matrix. For the Au/Ag nanoparticles, it can be found that the compressive strain existing in the shell is stronger than that on the center of core and reaches the maximum at the interface between the shell and core. In contrast, for the Ag/Au nanoparticles, the compressive strain applied on the core is much stronger than that at the interface and that in the shell. With the shell thickness increasing, both of the strains in the Au/Ag and Ag/Au nanoparticles increase as well. However, the strain gradient in the shell decreases gradually with the increasing of the shell thickness for both of Ag/Au ad Au/Ag nanoparticles. These results provide an effective method to manipulate the strain distributions of the Au/Ag and Ag/Au nanoparticles by tuning the thickness of the shell, which can further have significant influences on the microstructures and physical properties of Au/Ag and Ag/Au nanoparticles.


Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1050
Author(s):  
Francesco Ruffino

Ag and Au nanostructures became increasingly interesting due to their localized surface plasmon resonance properties. These properties can be successfully exploited in order to enhance the light trapping in solar cell devices by appropriate light scattering phenomena. In solar cell applications, the Ag or Au nanoparticles are, usually, supported on or embedded in a thin transparent conductive oxide layer, mainly AZO and ITO for inorganic solar cells and PEDOT:PSS for organic solar cells. However, the light scattering properties strongly depend on the shape and size of the metal nanostructures and on the optical properties of the surrounding environment. Therefore, the systems need to be well designed to maximize scattering and minimize the light absorption within the metal nanoparticles. In this regard, this work reports, in particular, results concerning calculations, by using the Mie theory, of the angle-dependent light scattering intensity (I(θ)) for spherical Ag and Au nanoparticles coated by a shell of AZO or ITO or PEDOT:PSS. I(θ) and scattering efficiency Qscatt for the spherical core–shell nanoparticles are calculated by changing the radius R of the spherical core (Ag or Au) and the thickness d of the shell (AZO, ITO, or PEDOT:PSS). For each combination of core–shell system, the evolution of I(θ) and Qscatt with the core and shell sizes is drawn and comparisons between the various types of systems is drawn at parity of core and shell sizes. For simplicity, the analysis is limited to spherical core–shell nanoparticles so as to use the Mie theory and to perform analytically exact calculations. However, the results of the present work, even if simplified, can help in establishing the general effect of the core and shell sizes on the light scattering properties of the core–shell nanoparticles, essential to prepare the nanoparticles with desired structure appropriate to the application.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chin-Wei Lin ◽  
Jian-Ming Chen ◽  
You-Jun Lin ◽  
Ling-Wei Chao ◽  
Sin-Yi Wei ◽  
...  

Abstract Recently, gold-coated magnetic nanoparticles have drawn the interest of researchers due to their unique magneto-plasmonic characteristics. Previous research has found that the magneto-optical Faraday effect of gold-coated magnetic nanoparticles can be effectively enhanced because of the surface plasmon resonance of the gold shell. Furthermore, gold-coated magnetic nanoparticles are ideal for biomedical applications because of their high stability and biocompatibility. In this work, we synthesized Fe3O4@Au core-shell nanoparticles and coated streptavidin (STA) on the surface. Streptavidin is a protein which can selectively bind to biotin with a strong affinity. STA is widely used in biotechnology research including enzyme-linked immunosorbent assay (ELISA), time-resolved immunofluorescence (TRFIA), biosensors, and targeted pharmaceuticals. The Faraday magneto-optical characteristics of the biofunctionalized Fe3O4@Au nanoparticles were measured and studied. We showed that the streptavidin-coated Fe3O4@Au nanoparticles still possessed the enhanced magneto-optical Faraday effect. As a result, the possibility of using biofunctionalized Fe3O4@Au nanoparticles for magneto-optical biomedical assays should be explored.


Nanoscale ◽  
2019 ◽  
Vol 11 (37) ◽  
pp. 17471-17477 ◽  
Author(s):  
Jiaqi Chen ◽  
Dejing Meng ◽  
Hui Wang ◽  
Haiyun Li ◽  
Yinglu Ji ◽  
...  

Using DMAB as the Raman internal reference, the spatial trajectory of modulating 4-ATP molecules was tracked during the shell growth process.


2004 ◽  
Vol 818 ◽  
Author(s):  
U. Wiedwald ◽  
J. Lindner ◽  
M. Spasova ◽  
Z. Frait ◽  
M. Hilgendorff ◽  
...  

AbstractFerromagnetic Resonance experiments are used to investigate the magnetic properties of monodisperse Co/CoO core-shell nanoparticles with diameters of about 10nm. From frequency- dependent measurements at various frequencies of 9-80 GHz the g-value is determined to be 2.13 which suggests an fcc bulk-like environment of the Co atoms within the core of the particles. This result yields a direct measure of the ratio of orbital to spin magnetic moment νL/νS=0.065. Moreover, from temperature-dependent measurements of the resonance field the anisotropy energy is extracted and found much lower than the hcp bulk value.


NANO ◽  
2014 ◽  
Vol 09 (04) ◽  
pp. 1450042 ◽  
Author(s):  
CONG-WANG ZHANG ◽  
CHANG-CHUN ZENG ◽  
YING XU

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.


RSC Advances ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 1700-1705 ◽  
Author(s):  
Hailong Zhang ◽  
Pengfei Cao ◽  
Jie Dou ◽  
Lin Cheng ◽  
Tiaoming Niu ◽  
...  

We present a new type of localized surface plasmon resonance (LSPR) sensor whose refractive index sensitivity can be improved by greatly increasing the plasmon wavelength red-shift of metal–semiconductor core–shell nanoparticles (CSNs).


2003 ◽  
Vol 774 ◽  
Author(s):  
Jiye Fang ◽  
Jibao He ◽  
Eun Young Shin ◽  
Deborah Grimm ◽  
Charles J. O'Connor ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document