scholarly journals Characterization of Biocompatible Gold Nanoparticles Synthesized by using Curcuma xanthorrhiza and their Catalytic Activity

2020 ◽  
Vol 16 (2) ◽  
pp. 214-225
Author(s):  
Khairiza Lubis ◽  
Nuannoi Chudapongse ◽  
Hau Van Doan ◽  
Oratai Weeranantanapan
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Ftir Spectroscopy ◽  
Dye Degradation ◽  
Chemical Properties ◽  
Reduction Process ◽  
Industrial Applications ◽  
Biological Synthesis ◽  
Curcuma Xanthorrhiza

Background: Based on various distinguished physical and chemical properties of gold nanoparticles, they have far wide applications in several areas of industry and medicine, such as catalysis, bio-sensor and drug delivery. Compared to a chemical method, biological synthesis is an economical and less toxic process, thus it is a better alternative for nanoparticle synthesis. In this study, an environmentally friendly method was chosen to produce AuNPs using Curcuma xanthorrhiza. Methods: Alkaline aqueous extract of C. xanthorrhiza rhizomes, which acts as a reducing and stabilizing agent was used to produce AuNPs by bio-reduction of HAuCl4. The formation of AuNPs was periodically monitored by UV-visible spectroscopy. The obtained AuNPs were characterized by Xray diffraction, energy dispersive spectroscopy, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared (FTIR) spectroscopy. Catalytic activity and toxicity of the AuNPs were evaluated. Results: The AuNPs obtained from this study mostly were spherical in shape with approximately 15 nm in size. The presence of functional groups derived from C. xanthorrhiza rhizome extract involved in the gold bio-reduction process was confirmed by the spectrum of FTIR spectroscopy. The biosynthesized AuNPs at the concentration of 0.5 μg/ml had catalytic activity in dye degradation of Congo red. The results showed that this biogenic AuNPs did not cause any toxicity to zebrafish embryos and all tested cell lines. Conclusion: The biocompatible AuNPs with catalytic activity were successfully fabricated with C. xanthorrhiza rhizome extract by simple eco-friendly and inexpensive method. This catalytic activity of the obtained AuNPs is potentially useful for industrial applications as well as nanoscience and nanotechnology.

scholarly journals Green Silver and Gold Nanoparticles: Biological Synthesis Approaches and Potentials for Biomedical Applications

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 844 ◽  
Author(s):  
Andrea Rónavári ◽  
Nóra Igaz ◽  
Dóra I. Adamecz ◽  
Bettina Szerencsés ◽  
Csaba Molnar ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Biomedical Applications ◽  
Biological Activities ◽  
Large Body ◽  
Chemical Properties ◽  
Biological Synthesis ◽  
Silver And Gold Nanoparticles ◽  
Comprehensive Collection ◽  
Synthetic Approaches ◽  
Physical And Chemical

The nanomaterial industry generates gigantic quantities of metal-based nanomaterials for various technological and biomedical applications; however, concomitantly, it places a massive burden on the environment by utilizing toxic chemicals for the production process and leaving hazardous waste materials behind. Moreover, the employed, often unpleasant chemicals can affect the biocompatibility of the generated particles and severely restrict their application possibilities. On these grounds, green synthetic approaches have emerged, offering eco-friendly, sustainable, nature-derived alternative production methods, thus attenuating the ecological footprint of the nanomaterial industry. In the last decade, a plethora of biological materials has been tested to probe their suitability for nanomaterial synthesis. Although most of these approaches were successful, a large body of evidence indicates that the green material or entity used for the production would substantially define the physical and chemical properties and as a consequence, the biological activities of the obtained nanomaterials. The present review provides a comprehensive collection of the most recent green methodologies, surveys the major nanoparticle characterization techniques and screens the effects triggered by the obtained nanomaterials in various living systems to give an impression on the biomedical potential of green synthesized silver and gold nanoparticles.

Magnetic Pd/Fe3O4 Composite: Synthesis, Structure, and Catalytic Activity

2014 ◽  
Vol 67 (10) ◽  
pp. 1387 ◽  
Author(s):  
Shi-Qiang Bai ◽  
Lu Jiang ◽  
Sheng-Li Huang ◽  
Ming Lin ◽  
Shuang-Yuan Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Reduction Process ◽  
Pd Nanoparticles ◽  
Pincer Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Thermal Stability ◽  
Transmission Electron

Composite Pd/Fe3O4 (1) was designed and synthesised by immobilization of tridentate pincer ligands with triethoxysilane groups on Fe3O4 nanoparticles, PdII complexation, and in-situ reduction process. The composite was characterised by transmission electron microscopy, scanning electron microscopy energy-dispersive X-ray spectroscopy, powder X-ray diffraction, vibrating sample magnetometer, Fourier transform infrared spectroscopy, thermogravimetric analysis, and Brunauer–Emmett–Teller analysis. The composite featured Pd nanoparticles of ~2–4 nm, exhibited good thermal stability and hydrophilic property as well as excellent catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol in water.

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.

Microwave Accelerated Green Synthesis of Gold Nanoparticles Using Gum Arabic and their Physico-Chemical Properties Assessments

2018 ◽  
Vol 232 (3) ◽  
pp. 325-343 ◽  
Author(s):  
Maryam Eskandari-Nojehdehi ◽  
Hoda Jafarizadeh-Malmiri ◽  
Abbas Jafarizad
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Exposure Time ◽  
Chemical Properties ◽  
Gum Arabic ◽  
Au Nps ◽  
Synthesis Conditions ◽  
Microwave Exposure ◽  
Physico Chemical

AbstractMicrowave enhanced gold nanoparticles (Au NPs) were synthesized using gum Arabic as both reducing and stabilizing agents. Response surface methodology was applied to study effects of the Au NPs synthesized parameters, namely, microwave exposure time (90–180 s) and the amount of AgNO3solution (1–10 mL) on the mean particle size, mixture solution color and concentration of the synthesized Au NPs. The colloidal solution containing well-dispersed and spherical fabricated Au NPs with mean particle size (22 nm) and maximum concentration (159 ppm) and color (1.12 absorbance unit, a.u.), were obtained at the optimal synthesis conditions, using 8.17 mL of HAuCl4(1 mM) and 2 mL of gum Arabic solution (4% w/v) during microwave exposure time of 180 s. The physico-chemical properties of the synthesized Au NPs at obtained optimum synthesis conditions were characterized by Fourier transform-infrared spectroscopy, UV-Vis spectroscopy, dynamic light scattering, X-ray diffraction, transmission electron microscopy and field emission scanning electron microscopy.

scholarly journals Myco-Fabricated Gold Nanoparticles from Aspergillus Tamarii MTCC5152, its Characterization and Dye Biodegradation

2021 ◽  
pp. 52-62
Author(s):  
Ragavy Radhakrishnan ◽  
Uthirappan Mani ◽  
Arumugam Gnanamani ◽  
Muthiah Shanmugavel
Keyword(s):  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Ftir Spectroscopy ◽  
Dye Degradation ◽  
Visual Observation ◽  
Surface Plasmon Resonance Peak ◽  
Sem Images ◽  
Aspergillus Tamarii ◽  
Plasmon Resonance Peak ◽  
Average Size

This work was initiated to investigate the myco-fabrication of gold nanoparticles (AuNPs) using a fungal strain, Aspergillus tamarii 5152 (A. tamarii MTCC 5152). The biosynthesized gold nanoparticles were characterized by visual observation, and using UV-Vis and FTIR spectroscopy, DSC, TGA, Zeta-potential, DLS and SEM analyses. NADH-dependent cofactor analysis and photocatalysis assays were carried out for NADH-dependent AuNPs biosynthesis and dye degradation ability. A maximum surface plasmon resonance peak for the AuNPs was recorded at 535 nm, followed by the identification of protein capping effect of the extract by FTIR spectroscopy. The average size (Z) of the nanoparticles observed was 39.15 nm, while SEM images showed crystallized rod-shaped structures ranging from 55-91 nm. A negative zeta potential of 10.5 mV showed repulsion between the nanoparticles, which indicates the stabilizing power of the fungal extract. Further, it was observed that NADH acts as a cofactor for the nanoparticle biosynthesis. The AuNPs were found to degrade crystal violet dye by 63%. From this study, it can be understood that the process of fungal mediated biosynthesis of AuNPs by A. tamarii MTCC 5152 is simple, less expensive, and could be utilized for bioremediation of toxic dye accumulation.

scholarly journals Predicting growth of gold nanoparticle by photochemical reduction process associated with mathematical modelling

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Hazidatul A. Hamlan ◽  
Norma Alias ◽  
Jia Cherng Chong ◽  
Hood Hong Ley ◽  
Noriah Bidin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Gold Nanoparticles ◽  
Numerical Analysis ◽  
Iterative Method ◽  
Mathematical Modelling ◽  
Chemical Properties ◽  
Reduction Process ◽  
Photochemical Reduction ◽  
New Generation ◽  
Photocatalytic Processes

Nowadays, to develop new generation of nanodevices, most researchers such as chemists, physicists, biologists, even the engineers are focusing their studies towards the uniqueness as well as the chemical properties of metal nanoparticles. Even, the mathematician also has governed the appropriate mathematical modelling regarding of properties of nanoparticles such as gold nanoparticles. In this paper, some experiment regarding the photochemical and photocatalytic processes for predicting the growth of gold nanoparticles from previous studies has been reviewed. Besides that, in observing the growth rate of gold nanoparticles, a mathematical modelling has been governed. Where, ultraviolet, UV radiation with wavelength of 366 nm and 253.7 nm has been fixed as the constant parameters. The governing equation is then solved numerically using some iterative method known as Jacobi and Gauss Seidel. The convergence of both methods is discussed in detail and the numerical analysis is presented in table form to justify and validate the convergence as well as the performance of the proposed iterative methods.

Controlling the Absorption of Gold Nanoparticles via Green Synthesis Using Sargassum crassifolium Extract

2018 ◽  
Vol 765 ◽  
pp. 44-48 ◽  
Author(s):  
Angeline F. Maceda ◽  
Johnny Jim S. Ouano ◽  
Mar Christian O. Que ◽  
Blessie A. Basilia ◽  
Melchor J. Potestas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Ftir Spectroscopy ◽  
Capping Agent ◽  
Visible Spectroscopy ◽  
Spectroscopy Analysis ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Uv Visible

This work controls the absorption of gold nanoparticles (GNPs) via green synthesis utilizingSargassumcrassifoliumextract. The amount of seaweed extract acts as both reducing (from Au+to Au0) and capping agent. TheS.crassifoliumextract is mainly composed of biomolecules such as protein and phenolic compounds which are responsible for the synthesis of GNPs. The synthesized GNPs were characterized using UV-Visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy and Transmission Electron Microscopy (TEM). UV-Vis spectra revealed peaks around 505 nm to 544 nm which corresponds to the Surface Plasmon Resonance (SPR) of GNPs. FTIR spectroscopy analysis showed peak at 825 cm-1and 1144 cm-1which corresponds to the signature peaks of GNPs. Polydisperse GNPs with varied sizes (between 5 nm to 300 nm) were further confirmed by TEM analysis.

scholarly journals Silver and Gold Nanoparticles from Limnophila rugosa Leaves: Biosynthesis, Characterization, and Catalytic Activity in Reduction of Nitrophenols

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Van Thuan Le ◽  
Ngoc Nhu Quynh Ngu ◽  
Tan Phat Chau ◽  
Thi Dung Nguyen ◽  
Van Toan Nguyen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Metal Nanoparticles ◽  
Leaf Extract ◽  
Noble Metal Nanoparticles ◽  
Metallic Ions ◽  
Ftir Microscopy ◽  
X Ray ◽  
Silver And Gold Nanoparticles

This study describes a simple green method for the synthesis of Limnophila rugosa leaf-extract-capped silver and gold nanoparticles without using any expensive toxic reductant or stabilizer. The noble metal nanoparticles were characterized by Fourier transform infrared (FTIR) microscopy, powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED), and dynamic light scattering (DLS) method. It has been found that the biosynthesized silver and gold nanoparticles are nearly spherical in shape with a mean particle size distribution of 87.5 nm and 122.8 nm, respectively. XRD and SAED patterns confirmed the crystalline nanostructure of the metal nanoparticles. FTIR spectra revealed the functional groups of biomolecules presented in the extract possibly responsible for reducing metallic ions and stabilizing formed nanoparticles. The biosynthesized metal nanoparticles have potential application in catalysis. Compared to previous reports, Limnophila rugosa leaf-extract-capped silver and gold nanoparticles exhibited a good catalytic activity in the reduction of several derivatives of nitrophenols including 1,4-dinitrobenzene, 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol.

scholarly journals Antioxidant and Catalytic Activity of Biosynthesized NiO Nanoparticles using Terminalia chebula Fruit Extract

2021 ◽  
Vol 34 (1) ◽  
pp. 35-41
Author(s):  
Md. Moulana Kareem ◽  
G. Vijaya Lakshmi
Keyword(s):  
Catalytic Activity ◽  
Zeta Potential ◽  
Xrd Analysis ◽  
Industrial Applications ◽  
Biological Synthesis ◽  
Terminalia Chebula ◽  
Nio Nanoparticles ◽  
Ambient Conditions ◽  
Fruit Extract ◽  
Synthesis Of Nanoparticles

Nowadays, the biological synthesis of nanoparticles attains researchers’ interest in removing hazardous pollutants from water. Due to eco-friendliness, cost effective, non-hazardous and avoids the usage of catalyst and stabilizing agents. Herein, biosynthesized NiO nanoparticles were prepared at the ambient conditions by using aqueous Terminalia chebula fruit extract. Terminalia chebula fruit extract contains polyphenolic compounds, terpenoids, carbohydrates and flavonoids, which can be responsible for the nucleation of metal nanoparticles in biological synthesis. The resulted biosynthesized NiO nanoparticles was characterized via UV, FTIR, zeta potential, XRD, EDX, SEM and TEM. The UV and XRD analysis confirmed the formation and cubic crystalline nature of biosynthesized NiO nanoparticles, receptively. FTIR, EDX and zeta potential confirmed the functional groups, elemental composition and surface charge. The phytochemicals present in Terminalia chebula were responsible for the reduction and stabilization of biosynthesized NiO nanoparticles. The average size of biosynthesized NiO was found to be 14.08 nm and spherical in shape with TEM. In addition, antioxidant and catalytic activities performance of the NiO nanoparticles were also investigated. Biosynthesized NiO nanoparticles showed antioxidant and catalytic activity against DPPH and Congo red dye, overall, the experimental results suggested that the NiO nanoparticle could be helpful for the industrial applications.

High resolution electron microscopy of lanthanum phosphate crystals

1978 ◽  
Vol 36 (1) ◽  
pp. 274-275
Author(s):  
J. C. Wheatley ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
High Resolution ◽  
Petroleum Industry ◽  
High Resolution Electron Microscopy ◽  
Lanthanum Phosphate ◽  
Good Catalyst ◽  
Resolution Electron ◽  
Good Catalytic Activity ◽  
Physical And Chemical

Rare-earth phosphates are of particular interest because of their catalytic properties associated with the hydrolysis of many aromatic chlorides in the petroleum industry. Lanthanum phosphates (LaPO4) which have been doped with small amounts of copper have shown increased catalytic activity (1). However the physical and chemical characteristics of the samples leading to good catalytic activity are not known.Many catalysts are amorphous and thus do not easily lend themselves to methods of investigation which would include electron microscopy. However, the LaPO4, crystals are quite suitable samples for high resolution techniques.The samples used were obtained from William L. Kehl of Gulf Research and Development Company. The electron microscopy was carried out on a JEOL JEM-100B which had been modified for high resolution microscopy (2). Standard high resolution techniques were employed. Three different sample types were observed: 669A-1-5-7 (poor catalyst), H-L-2 (good catalyst) and 27-011 (good catalyst).

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