scholarly journals Rapid Synthesis of Gold Nanoparticles with Ginger Waste using Microwave Irradiation

2019 ◽  
Vol 32 (2) ◽  
pp. 471-476
Author(s):  
G. Bhagavanth Reddy ◽  
B. Rajkumar ◽  
K. Girija Mangatayaru ◽  
T.V.D. Prasad Rao
Keyword(s):  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Microwave Irradiation ◽  
Pathogenic Bacteria ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
The Stability

In the present investigation, synthesis of gold nanoparticles (AuNPs) was carried out with microwave irradiation of HAuCl4 and the extract of ginger waste. Synthesized AuNPs were characterized by various techniques including UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The TEM images revealed that the nanoparticles were spherical in shape and the average particle size of the AuNPs was found to be approximately 6 ± 2 nm. The stability of gold nanoparticles was analyzed by zeta potential measurements. A negative zeta potential value of -18.4 mV indicates the stability of the AuNPs. Further, gold nanoparticles exhibited the excellent catalytic activity in reducing 4-nitrophenol to 4-aminophenol in the presence of NaBH4 (reducing agent), and it was found to depend on the amount of AuNPs and temperature. Gold nanoparticles did not show any significant antibacterial activity against the pathogenic bacteria studied.

scholarly journals Characterization, Antimicrobial and Antioxidant evaluation of biofabricated silver nanoparticles from endophytic Pantoea anthophila

2021 ◽  
Author(s):  
C. Nirmala ◽  
M Srid
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Pathogenic Bacteria ◽  
Average Particle Size ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Average Particle ◽  
X Ray ◽  
Uv Visible

Abstract Endophyte mediated nanoparticles fabrication was emerging as a new frontier in nanomedicines that produce high biocompatible and functionalized silver nanoparticles. In this study, silver nanoparticles were successfully biosynthesized from the extracellular extract of endophytic bacterium Pantoea anthophila isolated from the stem of Waltheria indica for the first time. The synthesised nanoparticles were characterized by UV-Visible and Fourier Transform Infra-Red spectroscopy. The structural analysis is done by X-ray diffraction and the stability was studied by dynamic light scattering and particle size analyser. The size and shape were observed by Transmission Electron Microscope, Scanning Electron Microscope and Energy Dispersive X-Ray spectrum. Further, the nanoparticles were evaluated for antimicrobial and antioxidant properties. Synthesized nanoparticle showed a strong absorption band in the UV-Visible range at 410 nm. The average particle size was found to be 16.8 nm with spherical shaped, crystalline nature. Good zones of inhibition at various ranges were detected against a broad range of human pathogenic bacteria and fungi. A strong free radical scavenging activity of silver nanoparticles with IC50 values 30.75, 19.47, 34.59, 41.12, 27.24, 28.16, 36.21 µg/ml was obtained that was comparable to the reference. The study suggests that the silver nanoparticles can be biosynthesised from endophytic P. anthophila metabolites with significant therapeutic potential. With proper validation, the biosynthesised silver nanoparticles can be developed as a promising antiviral and anticancer drug candidate.

scholarly journals Structure and Optical Property of Gold Nanoparticles Synthesized by Modified Polyol Method

2021 ◽  
Vol 31 (3) ◽  
Author(s):  
Long Nguyen Viet
Keyword(s):  
Gold Nanoparticles ◽  
Au Nanoparticles ◽  
Average Particle Size ◽  
Nir Spectroscopy ◽  
Polyol Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Modified Polyol Method

In this research, Au nanoparticles were successfully synthesized by modified polyol method with commercial precursors to be gold (III) chloride trihydrate (HAuCl4·3H2O), ethylene glycol (EG), poly(vinylpyrrolidone) (PVP), sodium borohydride (NaBH4). The structure and properties of as-prepared Au nanoparticles have been investigated by X ray diffraction (XRD), transmission electron microscopy (TEM), and UV-vis-NIR spectroscopy. As a result, Au nanoparticles with the average particle size of 28.80 nm were successfully synthesized in the range of about 50 nm. It is evidenced that the assembly of gold nanoparticles was presented in their nucleation, growth, and formation. 

MICROWAVE-ASSISTED SYNTHESIS AND CHARACTERIZATION OF CaS NANOPARTICLES

2012 ◽  
Vol 11 (05) ◽  
pp. 1250027 ◽  
Author(s):  
ARUP ROY ◽  
JAYANTA BHATTACHARYA
Keyword(s):  
Microwave Irradiation ◽  
Average Particle Size ◽  
Microwave Assisted Synthesis ◽  
Average Particle ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
One Step ◽  
Diffraction Patterns ◽  
Powder Analysis

CaS nanoparticles have been synthesized by microwave irradiation, using Ca(Ac)2 as Ca -precursor, and thioacetamide as S -source. The as-prepared sample has a uniform morphology and high purity. After heat treatment similar results were observed. Synthesized nanoparticles were characterized by X-ray powder analysis (XRD), field emission scanning microscopy (FESEM), high resolution transmission electron microscopy (TEM), and UV-Vis absorption spectroscopy. X-ray diffraction patterns suggest the formation of single cubical face of CaS having average particle size of 22 nm. HRTEM micrographs reveal well dispersed cubical morphology with a size distribution of 18–30 nm. Ultraviolet-visible (UV-Vis) spectroscopy shows absorption at 268 nm. In nutshell, microwave irradiation is proved to be a convenient, efficient and environmental-friendly one-step route to synthesize nanoparticles.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

Aquatic Fern (AzollaSp.) Assisted Synthesis of Gold Nanoparticles

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650008 ◽  
Author(s):  
Anal K. Jha ◽  
K. Prasad
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Surface Plasmon Resonance ◽  
Au Nanoparticles ◽  
X Ray ◽  
Aquatic Fern ◽  
Transmission Electron ◽  
Anthraquinone Glycosides ◽  
Uv Visible

Aquatic pteridophyte (Azolla sp.) was taken to assess its potential to synthesize the metal (Au) nanoparticles. The synthesized particles were characterized using X-ray, UV-visible, scanning and transmission electron microscopy analyses. Nanoparticles almost spherical in shape having the sizes of 5–17[Formula: see text]nm are found. UV-visible study revealed the surface plasmon resonance at 538[Formula: see text]nm. Responsible phytochemicals for the transformation were principally phenolics, tannins, anthraquinone glycosides and sugars present abundantly in the plant thereby bestowing it adaptive prodigality. Also, the use of Azolla sp. for the synthesis of gold nanoparticles offers the benefit of eco-friendliness.

Biosynthesis of Gold Nanoparticles with Serratia marcescens Bacteria

2015 ◽  
Vol 1132 ◽  
pp. 19-35
Author(s):  
S.O. Dozie-Nwachukwu ◽  
J.D. Obayemi ◽  
Y. Danyo ◽  
G. Etuk-Udo ◽  
N. Anuku ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Serratia Marcescens ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Color Changes ◽  
Transmission Electron ◽  
Helium Ion ◽  
Ph Conditions ◽  
Uv Visible ◽  
Ion Microscopy

This paper presents the biosynthesis of gold nanoparticles from the bacteria, Serratia marcescens.The intra-and extra-cellular synthesis of gold nanoparticles is shown to occur over a range of pH and incubation times in cell-free exracts and biomass ofserratia marcescensthat were reacted with 2.5mM Tetrachloroauric acid (HAuCl4). The formation of gold nanoparticles was identified initially via color changes from yellow auro-chloride to shades of red or purple in gold nanoparticle solutions. UV-Visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray spectroscopy (EDS), Helium Ion Microscopy (HIM) and Dynamic Light Scattering (DLS) were also used to characterize gold nanoparticles produced within a range of pH conditions. The results show clearly that the production of gold nanoparticles from cell-free extracts require shorter times than the production of gold nanoparticles from the biomass.

Gelatin as an ecofriendly natural polymer for preparing colloidal silver@gold nanobranches

2016 ◽  
Vol 5 (5) ◽  
Author(s):  
Phuong Phong Nguyen Thi ◽  
Dai Hai Nguyen
Keyword(s):  
Ph Value ◽  
Component Ratio ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Au Nps ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
The Stability ◽  
Maximum Absorption Wavelength

AbstractWe report star-shaped silver@gold (Ag@Au) nanoparticles (NPs) in gelatin suspensions for the purpose of enhancing the stability of Ag@Au NPs. In this case, Ag NPs were designed as nucleating agents, whereas gelatin was used as a protecting agent for Au development. Especially, variable gelatin concentrations were also prepared to explore its ability to increase the stability of Ag@Au NPs. The obtained samples were then characterized by UV-visible spectroscopy, transmission electron spectroscopy (TEM), X-ray diffraction, and Fourier transform infrared spectroscopy. The maximum absorption wavelength of all samples (566–580 nm) indicated that branched Ag@Au@gelatin NPs were successfully synthesized. In addition, our TEM results revealed that the size of branched Ag@Au@gelatin NPs was found to be between 20 and 45 nm as influenced by the component ratio and the pH value. These results can provide valuable insights into the improvement of Ag@Au NP stability in the presence of gelatin.

Biosynthesis and Characterization of Copper Nanoparticles Using a Bioflocculant Extracted from Alcaligenis faecalis HCB2

2019 ◽  
Vol 11 (11) ◽  
pp. 1064-1070 ◽  
Author(s):  
Nkosinathi G. Dlamini ◽  
Albertus K. Basson ◽  
V. S. R. Rajasekhar Pullabhotla
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Copper Nanoparticles ◽  
Average Particle Size ◽  
Thermo Gravimetric Analysis ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir

Bioflocculant from Alcaligenis faecalis HCB2 was used in the eco-friendly synthesis of the copper nanoparticles. Nanoparticles were characterized using a scanning electron microscope (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, thermo gravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FT-IR). The transmission electron microscopy images showed close to spherical shapes with an average particle size of ∼53 nm. Energy-dispersive X-ray spectroscopy analysis confirmed the presence of the Cu nanopartilces and also the other elements such as O, C, P, Ca, Cl, Na, K, Mg, and S originated from the bioflocculant. FT-IR results showed the presence of the –OH and –NH2 groups, aliphatic bonds, amide and Cu–O bonds. Powder X-ray diffraction peaks confirmed the presence of (111) and (220) planes of fcc structure at 2 of 33° and 47° respectively with no other impurity peaks.

DIELECTRIC PROPERTIES OF ULTRAFINE Zn-DOPED CaCu3Ti4O12 CERAMIC

2012 ◽  
Vol 02 (01) ◽  
pp. 1250007 ◽  
Author(s):  
LAXMAN SINGH ◽  
U. S. RAI ◽  
K. D. MANDAL ◽  
MADHU YASHPAL
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Single Phase ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sintered Powder

Ultrafine powder of CaCu2.80Zn0.20Ti4O12 ceramic was prepared using a novel semi-wet method. DTA/TG analysis of dry powder gives pre-information about formation of final product around 800°C. The formation of single phase was confirmed by X-ray diffraction analysis. The average particle size of sintered powder of the ceramic obtained from XRD and Transmission electron microscopy was found 59 nm and 102 nm, respectively. Energy Dispersive X-ray studies confirm the stoichiometry of the synthesized ceramic. Dielectric constant of the ceramic was found to be 2617 at room temperature at 1 kHz.

scholarly journals Sensitive and Selective Electrochemical Detection of Epirubicin as Anticancer Drug Based on Nickel Ferrite Decorated with Gold Nanoparticles

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1334
Author(s):  
Mohammad Mehmandoust ◽  
Nevin Erk ◽  
Ceren Karaman ◽  
Fatemeh Karimi ◽  
Sadegh Salmanpour
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Nickel Ferrite ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Differential Pulse ◽  
X Ray ◽  
Transmission Electron ◽  
The Stability ◽  
Electrochemical Electrode

The accurate and precise monitoring of epirubicin (EPR), one of the most widely used anticancer drugs, is significant for human and environmental health. In this context, we developed a highly sensitive electrochemical electrode for EPR detection based on nickel ferrite decorated with gold nanoparticles (Au@NiFe2O4) on the screen-printed electrode (SPE). Various spectral characteristic methods such as Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), energy-dispersive X-ray spectroscopy (EDX) and electrochemical impedance spectroscopy (EIS) were used to investigate the surface morphology and structure of the synthesized Au@NiFe2O4 nanocomposite. The novel decorated electrode exhibited a high electrocatalytic activity toward the electrooxidation of EPR, and a nanomolar limit of detection (5.3 nM) was estimated using differential pulse voltammetry (DPV) with linear concentration ranges from 0.01 to 0.7 and 0.7 to 3.6 µM. The stability, selectivity, repeatability reproducibility and reusability, with a very low electrode response detection limit, make it very appropriate for determining trace amounts of EPR in pharmaceutical and clinical preparations.

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