Shape and size separation of gold nanoparticles using glucose gradient density

Author(s):  
Marta Gordel ◽  
Joanna Olesiak-Banska ◽  
Katarzyna Matczyszyn ◽  
Claude Nogues ◽  
K. Pawlik ◽  
...  
2018 ◽  
Vol 122 (4) ◽  
pp. 2307-2314 ◽  
Author(s):  
Michael J. Ashley ◽  
Marc R. Bourgeois ◽  
Raghavendra R. Murthy ◽  
Christine R. Laramy ◽  
Michael B. Ross ◽  
...  

Author(s):  
Kangze Liu ◽  
Zhonglei He ◽  
Hugh J. Byrne ◽  
James Curtin ◽  
Furong Tian

The possibility of releasing gold nanoparticles (GNP) into the environment has been rapidly increasing with the wide spread and flourishing application of gold nanoparticles (GNPs) in a wide range of areas. Consequently, environmental effects of GNP, especially toxicities to living organisms have drawn great attention. However, their toxicological characteristics still remain unclear. Fungi, as the decomposers of the ecosystem, interact directly with the environment and critically control the overall health of the biosphere. Thus, their sensitivity to GNP toxicity is particularly important. The aim of this study was to evaluate the role of shape and size of GNPs on their toxicities to fungi, which could help reveal the ecotoxicity of GNPs. Aspergillus niger, Mucor hiemalis and Penicillium chrysogenum were chosen for toxicity assessment, and circular and star/flower-shaped GNPs sized from 0.7 nm to large aggregates of 400 nm have been synthesised. After mixed with GNPs and reacting agents of GNPs accordingly and incubated for 48 hours, the relative survival rates of each kind of fungus was calculated and compared. The results indicated that with similar sizes, star/flower-shaped GNPs are more toxic to fungi than circular-shaped GNPs; the toxicity of star/flower-shaped GNPs increases with smaller sizes. The results also showed that different species of fungus reacts differently to same GNPs, and Penicillium chrysogenum was relatively more sensitive under the exposure to GNPs.


2020 ◽  
Vol 10 ◽  
pp. 184798042096538
Author(s):  
Nur Liyana Razali ◽  
Marlia Morsin ◽  
Suratun Nafisah ◽  
Nur Zehan An’nisa Md Shah ◽  
Farhanahani Mahmud ◽  
...  

A simple technique of seed-mediated growth has been successfully performed to grow anisotropy gold nanoparticles on solid substrates. The growth of the gold nanoparticles has been carried out in the presence of a binary surfactant mixture of hexadecyltrimethylammonium bromide with two different molecular weights of a capping agent, namely polyvinylpyrrolidone: 40,000 and 55,000. In this study, the effect of process parameters, growth time and molecular weight of capping agent was investigated. The growth time shows a significant impact on the shape and size of nanoparticles. The shorter growth time produced small spherical to square-like shape particles, whereas bigger particles including nanorods, nanosquares and nanotriangles were formed with longer growth time. The shape controlling agent, polyvinylpyrrolidone, was used to synthesis gold nanoparticles. It was found that monodisperse gold nanoparticles with uniform shape and size are hardly obtained when polyvinylpyrrolidone 40,000 was used as capping agent. Polyvinylpyrrolidone 55,000 produced more uniform shape and size of gold nanoparticles. Thus, these process parameters were found affected to the size, shape, surface density and uniformity of gold nanoparticles. This sample was further applied as a sensing material in the detection of toxic fungicide, namely chlorothalonil. The sensitivity of the sensor system was determined by the changes in peak positions and intensities of the transverse and longitudinal surface plasmon resonance peaks on different medium, that is, air, deionized water and chlorothalonil solution. The sensor response of gold nanoparticles thin film in 30 mM chlorothalonil showed two resonance peaks in comparison to the control experiment without gold nanoparticle thin film. The gold nanoparticles thin film sensor was successfully synthesized and potentially useful as a sensing material for fungicide detection.


2022 ◽  
Author(s):  
Yutaro Yamashita ◽  
Shohei Tashiro ◽  
Yoshiki Ishii ◽  
Takayuki Uchihashi ◽  
Nobuyuki Matsushita ◽  
...  

The synthesis of branched gold nanoparticles (AuNPs) with shape- and size-specific optical properties requires effective control of the particle formation mechanism using appropriate reducing agents and protective agents that prevent...


RSC Advances ◽  
2015 ◽  
Vol 5 (22) ◽  
pp. 16672-16677 ◽  
Author(s):  
Mohamed Bouri ◽  
Rachid Salghi ◽  
Manuel Algarra ◽  
Mohammed Zougagh ◽  
Angel Ríos

A simple and rapid methodology to separate and characterize gold nanoparticles (AuNPs) in aqueous medium by capillary electrophoresis–evaporative light scattering detection (CE–ELSD) is presented.


Nano Letters ◽  
2010 ◽  
Vol 10 (4) ◽  
pp. 1433-1439 ◽  
Author(s):  
Kyoungweon Park ◽  
Hilmar Koerner ◽  
Richard A. Vaia

2006 ◽  
Vol 128 (10) ◽  
pp. 3190-3197 ◽  
Author(s):  
Scott F. Sweeney ◽  
Gerd H. Woehrle ◽  
James E. Hutchison

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