scholarly journals Microwave-Mediated Rapid Synthesis of Gold Nanoparticles Using Calotropis procera Latex and Study of Optical Properties

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ratul Kumar Das ◽  
Punuri Jayasekhar Babu ◽  
Nayanmoni Gogoi ◽  
Pragya Sharma ◽  
Utpal Bora

We report a microwave-mediated simple and rapid method of gold nanoparticles (GNPs) synthesis using latex of Calotropis procera. UV-Vis spectroscopic studies indicated the formation of GNPs. The GNPs were stable at room temperature (25°C) for six months. Transmission electron microscope (TEM) micrographs of the synthesized GNPs showed the formation of spherical nanoparticles with an average size of 13 ± 5 nm. SAED and XRD confirmed the crystalline nature of GNPs. Fourier transform infrared (FTIR) analysis indicated the presence of organic coating on the nanoparticles. Cytotoxicity of the GNPs was tested on HeLa and A549 and found to be nontoxic which was indicating that latex of Calotropis procera provided the nontoxic coating on GNPs, thus can be used as biomedical and pharmacological applications.

2020 ◽  
Vol 42 (3) ◽  
pp. 440-440
Author(s):  
Xin Bin Yang Xin Bin Yang ◽  
Chun Mei Wang Chun Mei Wang ◽  
Yu Huang Yu Huang

Gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) were synthesized by using water-soluble Kaempferol–3′–sulfonate acid sodium (KS) alone as the reducing agent. The UV-vis spectra confirmed the formation of the ks-AuNPs and ks-AgNPs which were stable for up to 3 months without any other stabilizing agents at room temperature. The TEM studies exhibited monodispersed and mainly spherical nanoparticles with the size in the range of 15-30 nm and 20-50 nm for ks-AuNPs and ks-AgNPs, respectively. The XRD revealed crystallinity of nanoparticles. The chemical state of Au and Ag on the surface of nanoparticles was analyzed by XPS. The FTIR analysis indicated that the hydroxyl of KS were responsible for the reduction of Au3+ and Ag+ to ks-AuNPs and ks-AgNPs, respectively. Cytotoxic activity of ks-AuNPs and ks-AgNPs on MCF-7 cells is higher than the KS.


2015 ◽  
Vol 233-234 ◽  
pp. 513-516 ◽  
Author(s):  
A.P. Safronov ◽  
Galina V. Kurlyandskaya ◽  
S.M. Bhagat ◽  
I.V. Beketov ◽  
A.M. Murzakaev ◽  
...  

Spherical nickel nanoparticles were prepared by the electrical explosion of wire. The as-prepared nanoparticles were modified immediately after fabrication at room temperature in order to provide tunable surface properties with focus on the development of composites filled with nanoparticles. Following liquid modificators were used: hexane, toluene and the solution of polystyrene in toluene. In one case the surface modification by carbon was made in gas phase as a result of hydrocarbon injection. The average size of the nanoparticles was about 50 nm and unit cell parameters were close to 0.351 nm. Detailed characterization was done by X-ray diffraction, transmission electron microscopy, and magnetization measurements. Sphericity was also checked using microwave resonant absorption.


2004 ◽  
Vol 818 ◽  
Author(s):  
Yanglong Hou ◽  
Hiroshi Kondoh ◽  
Toshiaki Ohta

AbstractThe combination of 1-adamantanecarboxylic acid and tri-alkylphosphine was applied to produce monodisperse FePd nanoparticles by the polyol reduction of palladium acetylacetonate and thermally decomposition of iron pentacarbonyl. Images of high resolution transmission electron microscopy (TEM) and X-ray diffraction (XRD) data indicate a highly monodisperse and crystalline nature of the FePd nanoparticles. Magnetic studies performed by Quantum Design SQUID magnetometer show that FePd (16nm) nanoparticles are superparamagnetic at room temperature.


Author(s):  
E. Romero Torres ◽  
M. Gutiérrez Arzaluz ◽  
V Mugica Alvarez ◽  
L. González Reyes ◽  
M. Torres Rodríguez ◽  
...  

The photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) using a Au/TiO2 catalyst and ultraviolet (UV) light energy source (9 mW/cm2) discussed. Gold nanoparticles were synthesized by controlled urea reduction and deposited on titanium dioxide (TiO2) by the deposition-precipitation method. The average size of the nanoparticles was 6-8 nm. X-ray diffraction (XRD) characterization confirmed that TiO2 was present in the anatase phase, whereas the presence and particle size of gold were determined by transmission electron microscopy (TEM). The results of the degradation showed that the activity of TiO2 was improved when Au nanoparticles were present on the surface. The reactions were performed at atmospheric pressure and room temperature.


Marine Drugs ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 38 ◽  
Author(s):  
Maria Sindhura John ◽  
Joseph Amruthraj Nagoth ◽  
Kesava Priyan Ramasamy ◽  
Alessio Mancini ◽  
Gabriele Giuli ◽  
...  

The synthesis of silver nanoparticles (AgNPs) by microorganisms recently gained a greater interest due to its potential to produce them in various sizes and morphologies. In this study, for AgNP biosynthesis, we used a new Pseudomonas strain isolated from a consortium associated with the Antarctic marine ciliate Euplotes focardii. After incubation of Pseudomonas cultures with 1 mM of AgNO3 at 22 °C, we obtained AgNPs within 24 h. Scanning electron (SEM) and transmission electron microscopy (TEM) revealed spherical polydispersed AgNPs in the size range of 20–70 nm. The average size was approximately 50 nm. Energy dispersive X-ray spectroscopy (EDS) showed the presence of a high intensity absorption peak at 3 keV, a distinctive property of nanocrystalline silver products. Fourier transform infrared (FTIR) spectroscopy found the presence of a high amount of AgNP-stabilizing proteins and other secondary metabolites. X-ray diffraction (XRD) revealed a face-centred cubic (fcc) diffraction spectrum with a crystalline nature. A comparative study between the chemically synthesized and Pseudomonas AgNPs revealed a higher antibacterial activity of the latter against common nosocomial pathogen microorganisms, including Escherichia coli, Staphylococcus aureus and Candida albicans. This study reports an efficient, rapid synthesis of stable AgNPs by a new Pseudomonas strain with high antimicrobial activity.


2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Sk Nurul Hasan ◽  
Braja Gopal Bag

The antioxidant activity of the endosperm extract of Borassus flabellifer (commonly known as Taal) has been studied against a long lived 2,2-diphenylpicrylhydrazyl (DPPH) radical at room temperature. The phytochemicals present in the endosperm extract have been utilized for the synthesis of stable gold nanoparticles at room temperature under very mild conditions. The synthesized gold nanoparticles were characterized by Surface Plasmon Resonance spectroscopy, High resolution transmission electron microscopy, X-Ray diffraction and FTIR studies and a mechanism for the synthesis of stabilized gold nanoparticles has been proposed.


2013 ◽  
Vol 481 ◽  
pp. 21-26 ◽  
Author(s):  
Huei Ruey Ong ◽  
Maksudur Rahman Khan ◽  
Ridzuan Ramli ◽  
Rosli Mohd Yunus

Copper nanoparticles (CuNPs) have been prepared by the reduction of copper chloride in glycerol using hydrazine at ambient conditions. The reduction process takes place under vigorous stirring for 8 h. The formation of CuNPs and size were confirmed by UV/Vis analysis and TEM imaging respectively. The experiment result showed that, 7.062 mM of hydrazine solution and 0.0147 mM of Cu2+ solution were needed to synthesize narrow size monodisperseCuNPs.The presence of nanoparticle was found after an induction period of 4 h and further reaction time, complete Cu0 state nanoparticle was obtained as deep red wine colour was observed. Stability study of CuNPs showed that the nanoparticles were stable up to 4 days. The particle size of the nanoparticles have been analysed by transmission electron microscopy (TEM) and the average size of CuNPs was in the range 2 to 10 nm.


2018 ◽  
Vol 34 (5) ◽  
pp. 2305-2312 ◽  
Author(s):  
Shohifah Annur ◽  
Sri Juari Santosa ◽  
Nurul Hidayat Aprilita

We have developed the spherical gold nanoparticles (AuNPs) with different size at room temperature using L-ascorbic acid as a reducing agent. Controlling pH of L-ascorbic acid from 2.0 to 10.0 caused the decreasing of AuNPs size when measured using particle size analyzer. The alkaline condition leads to increase the reactivity of L-ascorbic acid even at room temperature. The homogeneous AuNPs were achieved even the synthesis was conducted at different pH of L-ascorbic acid (pH 2.0 to 12.0). The investigation using Transmission Electron Microscopy (TEM) confirmed that AuNPs performed a spherical shape. SEM-EDX measurement performed a strong characteristic peak of Au appeared at 2.0 keV. This research could be used to control of AuNPs size when synthesized at room temperature. The AuNPs obtained at optimum condition was stable up to 3 months.


2013 ◽  
Vol 678 ◽  
pp. 136-139
Author(s):  
S. Kanimozhi ◽  
Dhandapani Vishnushankar ◽  
V. Veeravazhuthi

Lead sulfide (PbS) nanoparticles have been synthesized by photo chemical method and also in the dark ambient at room temperature. The pH of the solution is maintained by adding NaOH. The as-prepared PbS nanoparticles have been characterized by X-Ray Diffraction (XRD), Scanning electron microscopy (SEM), Energy-dispersive Analysis of X-ray (EDAX) and Transmission Electron Microscopy (TEM). XRD studies reveal the crystalline nature of the particles. Grain size values are calculated using Scherrer’s formula and compared with the standard values. SEM picture shows a flower like structure in the sample synthesized at dark ambient, whereas the samples synthesized in light reveals the presence of varied nanostructures like nanorods, nanowires and nanoparticles. Size of the photo chemically synthesized PbS particles observed from TEM lies between 30nm to 60nm. From EDAX we conclude that the composition is nearly stoichiometric.


2008 ◽  
Vol 8 (8) ◽  
pp. 3828-3837 ◽  
Author(s):  
Víctor Meza-Laguna ◽  
Elena V. Basiuk ◽  
Edgar Alvarez-Zauco ◽  
Taras Yu. Gromovoy ◽  
Oscar Amelines-Sarria ◽  
...  

We report on the preparation of fullerene C60 thin films chemically cross-linked with octane-1,8-dithiol, which are capable of binding gold nanoparticles. The formation of a polymer was directly proved by means of laser desorption/ionization time-of-flight mass spectra, in which we observed the cleavage of fullerene–dithiol polymer at different bonds. Fourier-transform infrared, Raman and UV-visible spectra of the functionalized films exhibited notorious changes due to the formation of new covalent bonds between C60 molecules and bifunctional thiol. We further demonstrated that the dithiol-functionalized fullerene can be employed as a support for stable and homogeneous deposition of gold nanoparticles. Their average size is about 5 nm according to high-resolution transmission electron microscopy observations, and up to 20 nm, as found from scanning tunneling microscopy images. The proposed binding mechanism is through a strong coordination attachment between Au nanoclusters and sulfur donor atoms of the functionalized fullerene, as supported by density functional theory calculations.


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