Radiation Induced Generation of Core–Shell Nanoparticles in Polyelectrolyte Films of Poly(acrylic acid)–Poly(ethylenimine) Complex with Copper and Silver Ions

2020 ◽  
Vol 124 (26) ◽  
pp. 14409-14418
Author(s):  
Dmitry I. Klimov ◽  
Elena A. Zezina ◽  
Yan V. Zubavichus ◽  
Sergey B. Zezin ◽  
Sergey N. Chvalun ◽  
...  
Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 688 ◽  
Author(s):  
Asli Yilmaz ◽  
Mehmet Yilmaz

Despite numerous attempts to fabricate the core–shell nanoparticles, novel, simple, and low-cost approaches are still required to produce these efficient nanosystems. In this study, we propose the synthesis of bimetallic core–shell nanoparticles of gold (AuNP) and silver (AgNP) nanostructures via a bioinspired polydopamine (PDOP) layer and their employment as a surface-enhanced Raman spectroscopy (SERS) platform. Herein, the PDOP layer was used as an interface between nanostructures as well as stabilizing and reducing agents for the deposition of silver ions onto the AuNPs. UV-vis absorption spectra and electron microscope images confirmed the deposition of the silver ions and the formation of core–shell nanoparticles. SERS activity tests indicated that both the PDOP thickness and silver deposition time are the dominant parameters that determine the SERS performances of the proposed core–shell system. In comparison to bare AuNPs, more than three times higher SERS signal intensity was obtained with an enhancement factor of 3.5 × 105.


MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2675-2681 ◽  
Author(s):  
Constanza Y. Flores ◽  
Estefania Achilli ◽  
Mariano Grasselli

ABSTRACTGold/albumin core/shell nanoparticles (Au/AlbNPs) was prepared by a novel aggregation/crosslinking technique and characterized by several spectroscopic and microscopy methods. Albumin, in presence of gold nanoparticles (AuNPs), is aggregated by the addition of ethanol and further stabilized by radiation-induced crosslinking using a 60Co source. Nanoconstructs are characterized to determine size, morphology and optical characteristics. The Au/AlbNPs were prepared in different ethanol and albumins concentrations. Results showed that it is possible to obtain Au/AlbNPs using ethanol 30 %v/v, albumin in different concentrations and an irradiation dose of 10 kGy. Au/AlbNP plasmon peak shifted to 530 nm, keeping the typical plasmon peak shape. The size of Au/AlbNPs is approximately double respect to the naked AuNPs and they show core/shell type morphology. The main amide peaks of albumin in FTIR spectrum can be found in the spectrum of nanoconstructs.


2014 ◽  
Vol 67 (1) ◽  
pp. 142 ◽  
Author(s):  
You Wei Zhang ◽  
Yan Chen ◽  
Jiong Xin Zhao

Antibacterial core–shell nanoparticles based on poly(hexamethylene guanidine hydrochloride) (PHMG) oligomers and poly(acrylic acid) (PAA) networks are efficiently fabricated via a facile one-step co-polymerization of acrylic acid and N,N′-methylenebisacrylamide on PHMG templates in aqueous solution. Dynamic light scattering, Fourier-transform infrared spectroscopy, and transmission electron microscopy observations were used to characterize the size, morphology, and structure of the nanoparticles, as well as the interactions between the components. Also, the stability of the nanoparticle dispersion against storage, pH value, salt, and temperature was investigated. The results show that the crosslinked PAA/PHMG nanoparticles are stabilized by electrostatic interactions. The core–shell structure of the nanoparticles was confirmed by transmission electron microscopy observation. The size of the nanoparticles increases substantially with extension of storage or with increase of the salt concentration. The nanoparticle dispersion is stable in a pH range of 2.0–4.0. The size change of the nanoparticles with pH of the medium is parabolic, and the minimum size is reached at pH 3.0. A rise of temperature leads to a slight and recoverable size increase of the nanoparticles. Antibacterial efficiency was evaluated quantitatively against Escherichia coli and Staphylococcus aureus by the plating method according to Standard JC/T 897–2002. The antibacterial activity against these two bacteria are both above 99.0 % at a nanoparticle concentration of 5 mg mL–1. This makes the nanoparticle dispersion a good candidate for the application of antibacterial water-based coatings and textiles coating.


2016 ◽  
Vol 7 (25) ◽  
pp. 4272-4283 ◽  
Author(s):  
Chloé Grazon ◽  
Jutta Rieger ◽  
Patricia Beaunier ◽  
Rachel Méallet-Renault ◽  
Gilles Clavier

Ultra-bright fluorescent nanoparticles with comb-like shells based on PEG and acrylic acid were obtained in water using an additive-free miniemulsion polymerization process.


2012 ◽  
Vol 27 (1) ◽  
pp. 95-101
Author(s):  
Shi-Bin LIU ◽  
Chun-Ying YANG ◽  
Zhong-Lin ZHANG ◽  
Dong-Hong DUAN ◽  
Xiao-Gang HAO ◽  
...  

2013 ◽  
Vol 20 (28) ◽  
pp. 3488-3499 ◽  
Author(s):  
Yon Jung ◽  
Hwanbum Lee ◽  
Jae Kim ◽  
Eun Koo ◽  
Keun Oh ◽  
...  

2021 ◽  
Vol 330 ◽  
pp. 129364
Author(s):  
Jinhua Wang ◽  
Jiamin Wu ◽  
Yuping Zhang ◽  
Xia Zhou ◽  
Ziwei Hu ◽  
...  

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