scholarly journals Metal-Enhanced Fluorescence and FRET in Multilayer Core-Shell Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Jérémie Asselin ◽  
Mathieu L. Viger ◽  
Denis Boudreau
Keyword(s):  
Aqueous Media ◽  
Physical Stability ◽  
Medical Diagnostics ◽  
Core Shell ◽  
Electromagnetic Spectrum ◽  
Shell Nanoparticles ◽  
Shell Nanostructures ◽  
Donor And Acceptor ◽  
Low Toxicity ◽  
Core Shell Nanoparticles

In recent years, various methods for the synthesis of fluorescent core-shell nanostructures were developed, optimized, and studied thoroughly in our research group. Metallic cores exhibiting plasmonic properties in the UV and visible regions of the electromagnetic spectrum were used to increase substantially the brightness and stability of organic fluorophores encapsulated in silica shells. Furthermore, the efficiency and range of Förster resonant energy transfer (FRET) between donor and acceptor molecules located in the vicinity of the metallic core was shown to be enhanced. Such multilayer nanoparticle architectures offer, in addition to the aforementioned advantages, excellent chemical and physical stability, solubility in aqueous media, low toxicity, and high detectability. In view of these enviable characteristics, a plethora of applications have been envisioned in biology, analytical chemistry, and medical diagnostics. In this paper, advances in the development of multilayer core-shell luminescent nanoparticle structures and selected applications to bioanalytical chemistry will be described.

Extinction Coefficient of Plasmonic Nickel Sulfide Nanocrystals and Gold-Nickel Sulfide Core-Shell Nanoparticles

2018 ◽  
Vol 233 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Rasmus Himstedt ◽  
Dominik Hinrichs ◽  
Dirk Dorfs
Keyword(s):  
Extinction Coefficient ◽  
Nickel Sulfide ◽  
Molar Extinction Coefficient ◽  
Localized Surface Plasmon ◽  
Core Shell ◽  
Electromagnetic Spectrum ◽  
Shell Nanoparticles ◽  
Extinction Coefficients ◽  
Optical Applications ◽  
Core Shell Nanoparticles

Abstract In the presented work, the molar extinction coefficient of plasmonic heazlewoodite (Ni3S2) nanoparticles and Au-Ni3S2 core-shell nanoparticles is determined for the first time. The results are compared to analogously determined extinction coefficients of pure Au nanocrystals (NCs), which themselves correlate very well with existing literature on the subject. The measured extinction coefficients at the localized surface plasmon resonance (LSPR) maximum wavelength of nickel sulfide particles are similar to the values of equally sized Au NCs. Therefore, considering the lower cost of the heazlewoodite material, it could be a reasonable alternative for optical applications of nanoparticles showing a LSPR in the visible regime of the electromagnetic spectrum. Furthermore, this study shows, that by growing a Ni3S2 shell onto a pure Au nanocrystal a highly tuneable optical material with variable LSPR frequency and molar extinction coefficient is obtained.

scholarly journals Core@shell Nanoparticles: Greener Synthesis Using Natural Plant Products

2018 ◽  
Vol 8 (3) ◽  
pp. 411 ◽  
Author(s):  
Mehrdad Khatami ◽  
Hajar Alijani ◽  
Meysam Nejad ◽  
Rajender Varma
Keyword(s):  
Large Scale ◽  
Hybrid Nanoparticles ◽  
Target Cells ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Environmental Friendliness ◽  
Shell Nanostructures ◽  
Greener Synthesis ◽  
Core Shell Nanoparticles ◽  
Synthesis Of Nanostructures

Among an array of hybrid nanoparticles, core-shell nanoparticles comprise of two or more materials, such as metals and biomolecules, wherein one of them forms the core at the center, while the other material/materials that were located around the central core develops a shell. Core-shell nanostructures are useful entities with high thermal and chemical stability, lower toxicity, greater solubility, and higher permeability to specific target cells. Plant or natural products-mediated synthesis of nanostructures refers to the use of plants or its extracts for the synthesis of nanostructures, an emerging field of sustainable nanotechnology. Various physiochemical and greener methods have been advanced for the synthesis of nanostructures, in contrast to conventional approaches that require the use of synthetic compounds for the assembly of nanostructures. Although several biological resources have been exploited for the synthesis of core-shell nanoparticles, but plant-based materials appear to be the ideal candidates for large-scale green synthesis of core-shell nanoparticles. This review summarizes the known strategies for the greener production of core-shell nanoparticles using plants extract or their derivatives and highlights their salient attributes, such as low costs, the lack of dependence on the use of any toxic materials, and the environmental friendliness for the sustainable assembly of stabile nanostructures.

scholarly journals Tunable Piezophotonic Effect on Core-Shell Nanoparticles Prepared by Laser Ablation in Liquids under External Voltage

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
A. K. Kodeary ◽  
S. M. Hamidi
Keyword(s):  
Laser Ablation ◽  
Lead Zirconate Titanate ◽  
Laser Pulses ◽  
Lead Zirconate ◽  
Core Shell ◽  
Laser Ablation In Liquid ◽  
Shell Nanoparticles ◽  
Nonlinear Properties ◽  
Shell Nanostructures ◽  
Core Shell Nanoparticles

We report an experimental study on the piezophotonic effect of gold and lead zirconate titanate (PbZrTiO3) nanoparticles (NPs) and also their core-shell nanostructures prepared by the laser ablation in liquid method. To obtain these NPs and composite materials, the targets were immersed in deionized water and a polymeric solution of polyvinyl pyrrolidone (PVP) under Nd:YAG laser pulses irradiation. Linear and nonlinear properties of these NPs were studied by optical spectroscopy and the Z-scan technique. Furthermore, tunable nonlinear properties of the NPs were measured under an external electric field under illumination to investigate the piezophotonic effect. Our results show that, at the interface of PZT and Au, due to the Schottky barrier, we have electron/hole recombination prevention, which leads to efficient enhancement in the nonlinear properties.

scholarly journals Recent Advancement in Functional Core-Shell Nanoparticles of Polymers: Synthesis, Physical Properties, and Applications in Medical Biotechnology

2013 ◽  
Vol 2013 ◽  
pp. 1-24 ◽  
Author(s):  
K. Santhosh Kumar ◽  
Vijay Bhooshan Kumar ◽  
Pradip Paik
Keyword(s):  
Chemical Properties ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Shell Nanostructures ◽  
Experimental Parameters ◽  
Recent Advancement ◽  
Core Shell Nanoparticles ◽  
Physical And Chemical ◽  
And Chemical Properties

This paper covers the core-shell nanomaterials, mainly, polymer-core polymer shell, polymer-core metal shell, and polymer-core nonmetal shells. Herein, various synthesis techniques, properties, and applications of these materials have been discussed. The detailed discussion of the properties with experimental parameters has been carried out. The various characterization techniques for the core-shell nanostructure have also been discussed. Their physical and chemical properties have been addressed. The future aspects of such core-shell nanostructures for biomedical and various other applications have been discussed with a special emphasis on their properties.

scholarly journals X-ray powder diffraction to analyse bimetallic core–shell nanoparticles (gold and palladium; 7–8 nm)

RSC Advances ◽  
2019 ◽  
Vol 9 (46) ◽  
pp. 26628-26636 ◽  
Author(s):  
A. Rostek ◽  
K. Loza ◽  
M. Heggen ◽  
M. Epple
Keyword(s):  
Gold Nanoparticles ◽  
Diffraction Study ◽  
Powder Diffraction ◽  
Au Nanoparticles ◽  
Vinyl Pyrrolidone ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Shell Nanostructures ◽  
Core Shell Nanoparticles

A comparative X-ray powder diffraction study on poly(N-vinyl pyrrolidone) (PVP)-stabilized palladium and gold nanoparticles and bimetallic Pd–Au nanoparticles (both types of core–shell nanostructures) was performed.

Improved Fabrication of PMMA/Ag Core-Shell Nanostructures with Two Steps

2008 ◽  
Vol 32 ◽  
pp. 33-38 ◽  
Author(s):  
Zhi Hua Chen ◽  
Zheng Wu ◽  
Jian Jun Bao ◽  
Gao Qing Max Lu ◽  
Qi Qing Zhang ◽  
...  
Keyword(s):  
Group Treatment ◽  
Particle Surface ◽  
Covalent Bond ◽  
Reduction Reaction ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Shell Nanostructures ◽  
Step Procedure ◽  
Improved Technique ◽  
Core Shell Nanoparticles

An improved technique to fabricate PMMA/Ag core-shell nanocomposite via a two-step procedure is reported. The procedure includes an improved particle surface treatment and an improved, subsequent Ag reduction reaction strategy. Well-dispersed PMMA/Ag core-shell nanoparticles with uniform particle size distribution were successfully fabricated using this improved technique. Different functional group treatment on the PMMA particle surface led to an electronically graded transition from the covalent bond of PMMA core to the metallic bond of silver shell. The improved fabrication technique thus allows a highly tailorable size of PMMA core and controllable thickness of Ag shell, which is crucial to producing a tunable plasmon resonance signal to different bio-/chem-environments.

scholarly journals Effect of calcination atmosphere on structural, optical and photocatalytic activity of TiO2/SnS2 core-shell nanostructures in the reduction of aqueous Cr(VI) to Cr(III)

2021 ◽  
Vol 15 (1) ◽  
pp. 58-68
Author(s):  
Shalini Sikdar ◽  
Tiju Thomas ◽  
Rao Ramachandra ◽  
Subramshu Bhattacharya
Keyword(s):  
Photocatalytic Activity ◽  
Single Step ◽  
Visible Range ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Shell Nanostructures ◽  
Important Means ◽  
Calcination Atmosphere ◽  
Core Shell Nanoparticles

Conversion of Cr(VI) to Cr(III) in mitigating pollution of water bodies is of significant importance to public health due to the fact that Cr(VI) is known to be a potent carcinogen, while Cr(III) is relatively low in toxicity. Photocatalytic approaches are considered as important means to achieve this reduction. Here, TiO2/SnS2 core-shell nanostructures have been produced using a single-step hydrothermal method and its photocatalytic activity is tested for the reduction of aqueous Cr(VI). The structural and optical properties of the as-synthesized products are characterized by XRD, HRTEM, Raman, FTIR, XPS and DRS techniques. The present work reveals that by calcining the core-shell nanoparticles in Ar atmosphere a defective Ti3O5 phase is formed as the core with low band gap, and hence, offers improved light absorption in the visible range. However, its photoactivity was found to be lower than that of the core-shell nanoparticles annealed in oxidizing atmosphere. The observed lower photoreduction was due to the presence of midgap states which acted as recombination centres and hence, reduced the photocatalytic activity.

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