scholarly journals Study of Green Synthesis of Ultrasmall Gold Nanoparticles Using Citrus Sinensis Peel

2019 ◽  
Vol 9 (12) ◽  
pp. 2423 ◽  
Author(s):  
Bo Yang ◽  
Feng Qi ◽  
Jingwen Tan ◽  
Tao Yu ◽  
Chengtun Qu
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Citrus Sinensis ◽  
Hydrodynamic Diameter ◽  
Surface Plasmon Resonance Peak ◽  
Alternative Source ◽  
Plasmon Resonance Peak ◽  
Transmission Electron ◽  
Ft Ir ◽  
First Time

Sweet orange (Citrus sinensis) peel, one of the most underutilized biowaste, was in this study employed for the green synthesis of gold nanoparticles (AuNPs) as an alternative source of reductant and stabilizer. Spherical AuNPs with narrow size distribution (1.75 ± 0.86 nm) were obtained by controlling pH and adjusting sequence for the first time. ultraviolet-visible (UV-vis) spectrophotometer, transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), dynamic light scattering (DLS) were applied to detect the characteristic surface plasmon resonance peak, morphological and aggregate characteristic, elementary composition and hydrodynamic diameter, respectively. The major functional groups in extract were tested by Fourier transform infrared(FT-IR) spectrophotometer to characterize the components which are responsible for the reduction and stabilization of AuNPs. The possible role of the components during the process of AuNPs synthesis is also discussed. The result of this study enriched the green source for ultra-small AuNPs synthesis, and will help to understand the mechanism of synthesis and stability of ultra-small AuNPs by fruit peels extract.

scholarly journals In vitro and in vivo applications of Euphorbia wallichii shoot extract-mediated gold nanospheres

2021 ◽  
Vol 10 (1) ◽  
pp. 101-111
Author(s):  
Rehman Ullah ◽  
Sumaira Shah ◽  
Zahir Muhammad ◽  
Sajjad Ali Shah ◽  
Shah Faisal ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Muscular Contraction ◽  
Surface Plasmon Resonance Peak ◽  
Plasmon Resonance Peak ◽  
Optical Absorption Peak ◽  
Visible Spectra ◽  
Scattering Spectra ◽  
Dose Dependent

Abstract The current study was designed to investigate the potential of Euphorbia wallichii shoot extract for reducting Au3+ and stabilizing gold nanoparticles. UV-visible spectra of gold nanoparticles showed obvious surface plasmon resonance peak at 548 nm. Microscopy (SEM and TEM) showed spherical dimensions, and the energy dispersive X-ray spectra displayed the strongest optical absorption peak for gold (Au) at 2.1 keV. Dynamic light scattering spectra represent polydispersed mixture with particulate diameter of 2.5–103.2 nm. The IR spectra confirm the potential functional groups of shoot extract responsible for the reduction of Au3+ to gold nanoparticles which exhibit tremendous antibacterial potential of 76.31%, 68.47%, 79.85%, 48.10%, and 65.53% against Escherichia coli, Staphylococcus aureus, Bacillus pumilus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, respectively. Gold nanoparticles showed markedly elevated fungicidal potency compared to the shoot extract alone against the tested fungal strains. IC50 for 2,2-diphenyl-1-picrylhydrazyl scavenging was 31.52, 18.29, and 15.32 µg/mL at 30, 60, and 90 min of reaction time, respectively. Both shoot extract and nanoparticles revealed 71% mortality at 100 µg/mL, with LD90 values of 310.56 µg/mL. Experimental mice acquired dose-dependent analgesia of 54.21%, 82.60%, and 86.53% when treated with gold nanoparticles at 50, 100, and 200 mg/kg bw. Inhibition of gastrointestinal muscular contraction was 21.16%, 30.49%, and 40.19% in mice feed with 50, 100, and 200 mg/kg bw, respectively.

scholarly journals Green Synthesis of Silver and Gold Nanoparticles via Sargassum serratifolium Extract for Catalytic Reduction of Organic Dyes

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Beomjin Kim ◽  
Woo Chang Song ◽  
Sun Young Park ◽  
Geuntae Park
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Catalytic Reduction ◽  
Organic Dyes ◽  
Low Cost ◽  
Inorganic Nanoparticles ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Sargassum Serratifolium

The green synthesis of inorganic nanoparticles (NPs) using bio-materials has attained enormous attention in recent years due to its simple, eco-friendly, low-cost and non-toxic nature. In this work, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by the marine algae extract, Sargassum serratifolium (SS). The characteristic studies of bio-synthesized SS-AgNPs and SS-AuNPs were carried out by using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Phytochemicals in the algae extract, such as meroterpenoids, acted as a capping agent for the NPs’ growth. The synthesized Ag and Au NPs were found to have important catalytic activity for the degradation of organic dyes, including methylene blue, rhodamine B and methyl orange. The reduction of dyes by SS-AgNPs and -AuNPs followed the pseudo-first order kinetics.

One-Step Preparation of Fibrous Aggregates of Gold Nanoparticles Using Aniline as Reducing Agent as well as Monomer

2007 ◽  
Vol 121-123 ◽  
pp. 251-254 ◽  
Author(s):  
Zhi Rui Guo ◽  
Y. DuanMu ◽  
Ning Gu
Keyword(s):  
Gold Nanoparticles ◽  
Reducing Agent ◽  
Time Dependent ◽  
Polymerization Process ◽  
Simultaneous Reduction ◽  
Transmission Electron ◽  
Ethanol Medium ◽  
One Step ◽  
Ft Ir ◽  
Medium Time

Nanoscaled fibrous aggregates of gold nanoparticles have been synthesized by a simultaneous reduction-oxidation polymerization process using aniline as reducing agent as well as monomer in an ethanol medium. Time-dependent UV-Vis absorption spectroscopy was used to track the formation process of gold nanoparticles. The transmission electron microscopy (TEM) images and Fourier transform infrared (FT-IR) spectrum of the as-preapred products indicate these gold nanoparticles were binded by the oxidation polymerization resultant of aniline.

Detecting H2S oscillatory response using surface plasmon spectroscopy

2013 ◽  
Vol 1552 ◽  
pp. 77-82 ◽  
Author(s):  
Enrico Della Gaspera ◽  
Alessandro Martucci
Keyword(s):  
Surface Plasmon ◽  
Au Nanoparticles ◽  
Resonance Peak ◽  
Surface Plasmon Resonance Peak ◽  
Plasmon Resonance Peak ◽  
Optical Absorbance ◽  
Oscillatory Response ◽  
Oxide Matrix ◽  
First Time ◽  
Surface Plasmon Spectroscopy

ABSTRACTThe oscillatory change in the optical absorbance of NiO-TiO2 film containing Au nanoparticles in the presence of H2S gas are investigated. The oscillatory phenomena could be monitored by looking at the variation of the surface plasmon resonance peak of the Au nanoparticles embedded in the TiO2-NiO matrix. Au nanoparticles act as optical probes in the detection of H2S, while the oxide matrix is responsible for the catalytic oxidation of H2S. To the best of our knowledge, it is the first time that oscillatory phenomena are monitored by optical spectroscopy.

scholarly journals Synthesis of V2O3/C composites with different morphologies by a facile route and phase transition properties of the compounds

2014 ◽  
Vol 32 (2) ◽  
pp. 236-242 ◽  
Author(s):  
Yifu Zhang ◽  
Nannan Wang ◽  
Yuting Huang ◽  
Chi Huang ◽  
Xiao Mei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Hydrothermal Route ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Potential Applications ◽  
Subsequent Calcination ◽  
Ft Ir ◽  
First Time

AbstractV2O3 and amorphous carbon composites (V2O3/C composites) with different morphologies (e.g. nanospheres, nanorods and nanosheets) were, for the first time, successfully synthesized by a facile hydrothermal route and subsequent calcination. The as-obtained samples were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometery (EDS), elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The morphology of V2O3/C composites could be easily controlled by varying the reaction time, and, as a result, V2O3/C composites with nanospheres, nanorods and nanosheets were selectively synthesized. Furthermore, the phase transition property of V2O3/C composites was measured by differential scanning calorimetry (DSC), suggesting that V2O3/C composites exhibit the phase transition similar to V2O3, which could expand the potential applications of materials related to V2O3 in the future.

scholarly journals Comparative Study on Inhibition of Pancreatic Cancer Cells by Resveratrol Gold Nanoparticles and a Resveratrol Nanoemulsion Prepared from Grape Skin

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1871
Author(s):  
Baskaran Stephen Inbaraj ◽  
Leng-Huei Hua ◽  
Bing-Huei Chen
Keyword(s):  
Pancreatic Cancer ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Cancer Cells ◽  
Surface Plasmon Resonance Peak ◽  
Grape Skin ◽  
Plasmon Resonance Peak ◽  
Mean Particle Size ◽  
Pancreatic Cancer Cells

Resveratrol, a phenolic compound possessing vital biological activities such as anti-cancer, is present abundantly in grape skin, a waste produced during the processing of grape juice. The objectives of this study were to prepare resveratrol-gold nanoparticles and a resveratrol nanoemulsion from grape skin and study their inhibition effects on pancreatic cancer cells BxPC-3. The spherical-shaped citrate gold nanoparticles (GNPs) and resveratrol-gold nanoparticles (R-GNPs) were, respectively, prepared with a surface plasmon resonance peak at 528 and 538 nm, mean particle size of 20.8 and 11.9 nm, and zeta-potential at −32.7 and −66.7 mV, by controlling an appropriate concentration of citrate/resveratrol and gold chloride as well as stirring time and temperature. The resveratrol nanoemulsion, composed of soybean oil, Tween 80, and sucrose fatty acid ester in glycerol and water, possessed a high storage stability with a mean particle size of 14.1 nm, zeta-potential of −49.7 mV, and encapsulation efficiency of 95.5%. An antiproliferation study revealed that both R-GNPs and resveratrol nanoemulsion could effectively inhibit the growth of pancreatic cancer cells BxPC-3, with the latter showing a higher inhibition effect. Western blot analysis implied that both can down-regulate expressions of cyclin A, cyclin B, CDK1, and CDK2 and up-regulate expressions of p53 and p21, accompanied by enhancing cytochrome C expression, decreasing BcL-2 expression, increasing Bax expression, and leading to the elevation of caspase-8, caspase-9, and caspase-3 activities for cell apoptosis execution. Future research is needed to study the inhibition of pancreatic tumors in vivo by R-GNPs and resveratrol nanoemulsions.

Enhanced optical, morphological, dielectric, and conductivity properties of gold nanoparticles doped PVA/CMC blend as an application in organoelectronic devices

2021 ◽  
Author(s):  
M. R. Atta ◽  
Qana M. Alsulami ◽  
G. M. Asnag ◽  
A . rajeh
Keyword(s):  
Gold Nanoparticles ◽  
Stevia Rebaudiana ◽  
Ultra Violet ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Low Frequencies ◽  
Bright Spots ◽  
Transmission Electron ◽  
Ft Ir ◽  
Mobile Charges

Abstract Stevia rebaudiana plant leaves were used for biosynthesis of gold nanoparticles (AuNPs). Transmission electron microscope ( TEM ) images showed various shapes and sizes of AuNPs. Various amounts of AuNPs were added to polyvinyl alcohol/carboxymethylcellulose ( PVA / CMC , 40/60) via the casting method. The X-ray diffraction (XRD) spectrum of pure blend shows the amorphous nature of the blend. FT-IR spectra showed the interaction between PVA / CMC and AuNPs. The ultra-violet and visible (UV/VIS.) spectra showed emerge new peak of surface plasmon resonance ( SPR ) of AuNPs for the filled samples. SEM images showed bright spots on the sample's surface, which was attributed to AuNPs. AC conductivity exhibited enhancement after the addition of gold nanoparticles. The ε′ and ε″ were reduced with increasing the frequency due to direction dipoles of applied electric field. Because of the mobile charges inside the polymeric backbone, higher values of ε′ and ε″ were observed at low frequencies. The tanδ showed increased with an increase in AuNPs concentration and at the decrease the frequency, as expected.

Facile and Novel Synthesis of Spiky Gold Nanoparticles as an Efficient Antimicrobial Agent against Pseudomonas Aeruginosa

2021 ◽  
Vol 24 ◽  
Author(s):  
Farooq Aziz ◽  
Muhammad Rashid ◽  
Mubashar Rehman ◽  
Muhammad Rafique ◽  
Muhammad Imran
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gold Nanoparticles ◽  
Biomedical Applications ◽  
Antibacterial Agents ◽  
Reduction Method ◽  
Surface Plasmon Resonance Peak ◽  
Gram Negative Bacteria ◽  
Plasmon Resonance Peak ◽  
Gram Negative ◽  
Novel Synthesis

Aims: The study aims to develop advanced antibacterial agents as nanoparticles instead of antibiotics due to the emergence of antimicrobial resistance. Background: Pseudomonas aeruginosa is capable of causing many diseases, including severe bacterial pneumonia. There is a need for an efficient antibacterial agent to kill these pathogens. Objective: The objective of the study is to synthesize advanced antibacterial agents as nanoparticles for biomedical applications that can play a vital role in killing Gram-negative bacteria (Pseudomonas aeruginosa). Method: A novel fabricated growth of hydrophilic spiky gold nanoparticles (SGNPs) via reduction method is reported. Results: The surface plasmon resonance peak of the synthesized SGNPs was tuned under the near-infrared range. The SGNPs have anisotropic and spiky morphology with 68 nm size and -58 mV surface charge. They are pure, possessing adsorption similar to the organic material. Pseudomonas aeruginosa treated with synthesized SGNPs showed 60% bacterial death at the concentration of 100 μM. Conclusion: This work consists of the novel synthesis of SGNPs via a safe and simple reduction method. The synthesized SGNPs exhibit strong antibacterial activity against the Gram-negative bacteria Pseudomonas aeruginosa measured using a microplate assay test. The result showed that these SGNPs are ideal for biomedical applications.

Role of Collagen Concentration in Stability of Star-Shaped Silver@Gold Nanoparticles

2016 ◽  
Vol 40 ◽  
pp. 113-119 ◽  
Author(s):  
Phuong Phong Nguyen Thi ◽  
Minh Tien Nguyen ◽  
Dai Hai Nguyen
Keyword(s):  
Gold Nanoparticles ◽  
Ph Value ◽  
Critical Role ◽  
Component Ratio ◽  
Surface Plasmon Resonance Peak ◽  
Collagen Concentration ◽  
Plasmon Resonance Peak ◽  
Nanoparticles Stability ◽  
The Stability ◽  
Growth Approach

In this report, star-shaped silver@gold (Ag@Au) nanoparticles were synthesized in collagen (Coll) suspensions by a seeding growth approach. The silver nanoparticles were used as seeds for Au development. Coll was used as a protecting agent and the effect of its concentration on stability was also examined. Obtained nanoparticles were then characterized by UV-Vis, TEM, XRD and FTIR. The result was confirmed by the maximum surface plasmon resonance peak at 566-580 nm for each sample indicating the formation of branched Ag@Au@Coll NPs. The average diameters of the branched Ag@Au@Coll NPs were revealed to be 30-50 nm depending on the corresponding component ratio and the pH value. It is interesting to note that the concentration of Coll plays a critical role in the stability of the star-shaped gold nanoparticles. The results offer an understanding of the handling of the electronic and the silver@gold based nanoparticles stability properties.

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