scholarly journals Aqueous-Phase Catalytic Chemical Reduction of p-Nitrophenol Employing Soluble Gold Nanoparticles with Different Shapes

Catalysts ◽  
2016 ◽  
Vol 6 (12) ◽  
pp. 215 ◽  
Author(s):  
Francyelle de Oliveira ◽  
Lucas Nascimento ◽  
Claudia Calado ◽  
Mario Meneghetti ◽  
Monique da Silva
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Phase ◽  
Chemical Reduction ◽  
Different Shapes

scholarly journals Protein-Coated Aryl Modified Gold Nanoparticles for Cellular Uptake Study by Osteosarcoma Cancer Cells

2020 ◽  
Author(s):  
Mehvesh Hameed ◽  
Seema Panicker ◽  
Sallam Hasan Abdallah ◽  
Amir A. Khan ◽  
Changseok Han ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cancer Cells ◽  
Cellular Uptake ◽  
Phase Transfer ◽  
Chemical Reduction ◽  
Uptake Study ◽  
Stabilizing Agents ◽  
Coated Nanoparticles ◽  
Green Route ◽  
The Difference

We synthesized protein-coated gold nanoparticles using green and chemical reduction routes for cellular uptake study. In the current work, we coated gold-aryl nanoparticles of the type AuNPs-C<sub>6</sub>H<sub>4</sub>-4-COOH with BSA, collagen, zein and lysozyme proteins. Both routes were carried out without phase-transfer catalysts or extraneous stabilizing agents. High crystallinity of the AuNPs synthesized by the green route can be seen in the transmission electron microscopy images. <a>Osteosarcoma cancer cells are malignant bone tumors with abnormal cellular functions. Studies using MG-63 cells will provide mechanistic suggestions on the details of the amplification in tumors. </a>We studied the cellular uptake of the bioconjugates by MG-63 osteosarcoma cells using laser confocal fluorescence microscopy (LCFM) and flow cytometry. In the LCFM study, BSA-AuNPs was uptaken most efficiently of all protein-coated gold nanoparticles synthesized by the green route. Zein and lysozyme coated nanoparticles, though small sizes, prepared by the green method were not efficiently uptaken by MG-63. The two nanoparticles are negatively charged and zein is also a hydrophobic coat. The difference in hydrophobicity and charge might have affected the internalization. All of those coated nanoparticles that were efficiently uptaken can potentially be used as diagnostic and therapeutic agents for osteosarcoma.

scholarly journals Influence of reducing agents and surfactants on size and shape of silver fine powder particles

2014 ◽  
Vol 20 (2) ◽  
pp. 73-88 ◽  
Author(s):  
Stevan P. Dimitrijević ◽  
Željko Kamberović ◽  
Marija Korać ◽  
Zoran Anđić ◽  
Silvana Dimitrijević ◽  
...  
Keyword(s):  
Chemical Reduction ◽  
Nitrate Solution ◽  
Fine Powder ◽  
Production Scale ◽  
Scale Reduction ◽  
Primary Particles ◽  
Powder Particles ◽  
Different Shapes ◽  
Average Size ◽  
Scanning Electron

Silver fine powder with different shapes and sizes were prepared by chemical reduction and characterized by scanning electron microscope. In this paper was presented the method for the preparation of the fine Ag powder with particles size smaller than 2.5 µm with suitability for the mass-production scale. Reduction was performed from nitrate solution directly by vigorous stirring at room temperature by three different reduction agents, with and without presence of two dispersants. Scanning electron microscopy revealed the preferred size of the particles obtained in all experiments with aim of the protecting agent. Larger particles and wider size distribution were obtained without surfactants although with average size of about 1 µm and small quantity of larger clusters of primary particles that is out of the fine powder classification. High purity, 99.999%, of silver was obtained in every experiment. 

Potential of rod, sphere and semi-cube shaped gold nanoparticles to induce cytotoxicity and genotoxicity in human blood lymphocytes in vitro

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Mona A.M. Abo-Zeid ◽  
Thomas Liehr ◽  
Amira M. Gamal-Eldeen ◽  
Mahmoud Zawrah ◽  
Mostafa Ali ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Gold Nanoparticles ◽  
Mitotic Activity ◽  
Human Blood ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Blood Lymphocytes ◽  
Human Blood Lymphocytes ◽  
Different Shapes

AbstractGold nanoparticles (GNPs) are intended to be used in nanomedicine. Due to nanotechnology innovation GNPs of variable sizes and in different shapes including rods, spheres, cubes, etc., can easily be produced. The aim of the present studies was to evaluate the cyto-and genotoxicity inducible by different shaped GNPs on normal human peripheral blood lymphocytes.Four different shapes of GNPs including big rod GNPs (BR-GNPs, 50 nm), small rod GNPs (SR-GNPs, 30 nm), sphere GNPs (S-GNPs, 15 nm) and semi-cube GNPs (SC-GNPs, 15 nm) were studied. Cultured human blood lymphocytes were treated with different concentrations of these GNPs for 24 h in vitro. Cytotoxicity was evaluated based on the mitotic index (MI), while genotoxicity was studied by an interphase-fluorescence in situ hybridization (I-FISH) assay. The following genes were studied in I-FISH:The lowest concentration of BR-GNPs neither had an effect mitotic activity nor enhanced gain or loss of examined gene signals in a significant manner with I-FSH. Other concentrations of BR-GNPs, SR-GNPs, S-GNPs and SC-GNPs with all concentrations inhibited the mitotic activity of the cells and reduced the cell proliferation highly significantly. The different types of GNPs initiated the duplication ofGNPs at high concentration can reduce the cell proliferation and induce DNA damage. Low concentration of rod-shaped GNPs at 50 nm was safe on human lymphocytes. Further research studies are required to optimize the concentration, shape and size of GNPs before using them in nanomedicine.

Electrooxidation of Methanol on Carbon Supported Gold Nanoparticles

2013 ◽  
Vol 313-314 ◽  
pp. 232-236
Author(s):  
Dan Zhang
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Competitive Adsorption ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Carbon Support ◽  
Transmission Electron ◽  
Supported Gold Nanoparticles ◽  
Supported Gold

Activated carbon supported gold nanoparticles (Au/C) were prepared by a chemical reduction process using NaBH4as a reducing agent. The characterization of transmission electron microscope indicated that the Au nanoparticles (AuNPs) in the Au/C catalyst were highly well dispersed on the carbon support. The catalytic activity of the Au/C catalyst for the methanol electrooxidation (MEO) was investigated by the cyclic voltammetry (CV). The results displayed that the Au/C catalyst exhibited a favorable catalytic activity towards the MEO in alkaline solution. Moreover, the competitive adsorption between OH-and CH3OH on the surface of the AuNPs in the Au/C catalyst existed in the course of the MEO. Based on this competitive adsorption, the mechanism of the MEO on the Au/C catalyst was further investigated.

Transfer of hydrophobic colloidal gold nanoparticles to aqueous phase using catecholamines

2020 ◽  
Vol 315 ◽  
pp. 113796
Author(s):  
Zehra Karaagac ◽  
Osman Tolga Gul ◽  
Nilay Ildiz ◽  
Ismail Ocsoy
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Phase ◽  
Colloidal Gold ◽  
Colloidal Gold Nanoparticles
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