A Simple, Rapid, and Green Synthesis of Capped Gold Nanospheres and Nanorods Using Aqueous Extract of Azolla

2013 ◽  
Vol 1 ◽  
pp. 194308921350701 ◽  
Author(s):  
Prashant Singh
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Extract ◽  
Metallic Nanoparticles ◽  
Elastic Light Scattering ◽  
Environment Friendly ◽  
Blue Green Algae ◽  
Material Chemistry ◽  
Transmission Electron ◽  
Different Shapes ◽  
First Time

In the last few decades, an increasing commercial demand for metal nanoparticles is found due to their numerous applications in various fields such as electronics, catalysis in organic synthesis, material chemistry, energy, and medicine. Metallic nanoparticles are traditionally synthesized by wet chemical techniques, wherein the chemicals used are quite harmful and flammable. Herein, we reported a cheap and environment-friendly procedure for the synthesis of capped gold nanoparticles of different shapes from aqueous solution of tetrachloroauric acid (HAuCl4) using aqueous extract of Azolla pinnata, blue-green algae used as a reducing as well as capping agent. The so-prepared gold nanoparticles were well characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), and quasi-elastic light scattering (QELS) techniques. The TEM showed nearly uniform distribution of the particles in water, which is again confirmed by QELS. This is for the first time that aqueous extract of A. pinnata was used for the synthesis of gold nanoparticles.

scholarly journals Application of dissolvable Mg/Al layered double hydroxides as an adsorbent for the dispersive solid phase extraction of gold nanoparticles prior to their determination by atomic absorption spectrometry

2020 ◽  
Vol 12 (3) ◽  
pp. 368-375
Author(s):  
Tatiana G. Choleva ◽  
Dimosthenis L. Giokas
Keyword(s):  
Gold Nanoparticles ◽  
Solid Phase Extraction ◽  
Layered Double Hydroxides ◽  
Metallic Nanoparticles ◽  
Solid Phase ◽  
Absorption Spectrometry ◽  
Phase Extraction ◽  
Dispersive Solid Phase Extraction ◽  
Double Hydroxides ◽  
First Time

In this work, dissolvable layered double hydroxides (LDHs) were used for the first time for the extraction and preconcentration of metallic nanoparticles from water samples.

scholarly journals Biosynthesis of Silver and Gold Nanoparticles Using Aqueous Extract from Crinum latifolium Leaf and Their Applications Forward Antibacterial Effect and Wastewater Treatment

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Thanh-Truc Vo ◽  
Thi Thanh-Ngan Nguyen ◽  
Thi Thanh-Tam Huynh ◽  
Thi Thuy-Trang Vo ◽  
Thi Thuy-Nhung Nguyen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Extract ◽  
Metallic Nanoparticles ◽  
Antibacterial Effect ◽  
Average Diameter ◽  
Catalytic Performance ◽  
Biologically Active ◽  
Bacterial Strains ◽  
Uv Visible ◽  
Average Size

Crinum latifolium (CL) leaf is a source of various biologically active compounds such as alkaloid and phenolic compounds, which exhibit anti-inflammatory, antitumor, and antimicrobial effects. In the purpose of expanding applications for the field of bionanotechnology, we report biosynthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) by using aqueous extract from C. latifolium leaf and explore antibacterial activity and catalytic performance for degradation of pollutants. The formation of CL-AgNPs and CL-AuNPs is confirmed and optimized by UV-visible spectroscopy with surface plasmon resonance (SPR) peaks at around 402 and 539 nm, respectively. The spherical CL-AgNPs have an average diameter of 20.5 nm and the multishaped CL-AuNPs possess an average size of 17.6 nm. The actions of four bacterial strains were strongly inhibited by using the CL-AgNPs. Furthermore, the biosynthesized metallic nanoparticles (MNPs) exhibited the excellent catalytic degradation performance of pollutants.

scholarly journals Kinetically Controlled Growth And Shape Formation Mechanism Of Platinum Nanoparticles

1998 ◽  
Vol 4 (S2) ◽  
pp. 746-747
Author(s):  
Janet M. Petroski ◽  
Zhong L. Wang ◽  
Travis C. Green ◽  
Mostafa A. El-Sayed
Keyword(s):  
Platinum Nanoparticles ◽  
Polymer Concentration ◽  
Pt Nanoparticles ◽  
Colloidal Nanoparticles ◽  
Shape Distribution ◽  
Catalytic Activities ◽  
Stages Of Growth ◽  
Transmission Electron ◽  
Different Shapes ◽  
First Time

Many studies on colloidal nanoparticles have focused on the control of nanoparticle size and correlated this to the catalytic activity. Recently, our group has reported for the first time a technique that controlled the shape distribution of Pt nanoparticles. This was done by varying the concentration of the capping polymer and the platinum ion ratio used in the reductive synthesis of colloidal nanoparticles at room temperature. Cubic, tetrahedral and truncated octahedral (TO) particles have been prepared, making it possible to study the catalytic activities of nanoparticles with different shapes and facets.Using transmission electron microscopy (TEM), we imaged the shapes and determined the shape distribution of platinum nanoparticles at different stages of their growth as a function of time. The small nanoparticles formed during the early stages of growth or at high polymer concentration displayed distributions with a dominance of tetrahedral shapes (see Figure la).

XAS analysis of iron and palladium bonded to a polysaccharide produced anaerobically by a strain ofKlebsiella oxytoca

2015 ◽  
Vol 22 (5) ◽  
pp. 1215-1226 ◽  
Author(s):  
Iztok Arčon ◽  
Stefano Paganelli ◽  
Oreste Piccolo ◽  
Michele Gallo ◽  
Katarina Vogel-Mikuš ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Metallic Nanoparticles ◽  
Klebsiella Oxytoca ◽  
Anaerobic Culture ◽  
X Ray ◽  
Nano Crystalline ◽  
Transmission Electron ◽  
First Time ◽  
X Ray Absorption ◽  
Metallic Species

Klebsiella oxytocaBAS-10 ferments citrate to acetic acid and CO2, and secretes a specific exopolysaccharide (EPS), which is able to bind different metallic species. These biomaterials may be used for different biotechnological purposes, including applications as innovative green biogenerated catalysts. In production of biogenerated Pd species, the Fe(III) as ferric citrate is added to anaerobic culture ofK. oxytocaBAS-10, in the presence of palladium species, to increase the EPS secretion and improve Pd-EPS yield. In this process, bi-metallic (FePd-EPS) biomaterials were produced for the first time. The morphology of bi-metallic EPS, and the chemical state of the two metals in the FePd-EPS, are investigated by transmission electron microscopy, Fourier transform infra-red spectroscopy, micro-X-ray fluorescence, and X-ray absorption spectroscopy methods (XANES and EXAFS), and compared with mono-metallic Pd-EPS and Fe-EPS complexes. Iron in FePd-EPS is in the mineralized form of iron oxides/hydroxides, predominantly in the form of Fe3+, with a small amount of Fe2+in the structure, most probably a mixture of different nano-crystalline iron oxides and hydroxides, as in mono-metallic Fe-EPS. Palladium is found as Pd(0) in the form of metallic nanoparticles with face-centred cubic structure in both bi-metallic (FePd-EPS) and mono-metallic (Pd-EPS) species. In bi-metallic species, Pd and Fe nanoparticles agglomerate in larger clusters, but they remain spatially separated. The catalytic ability of bi-metallic species (FePd-EPS) in a hydrodechlorination reaction is improved in comparison with mono-metallic Pd-EPS.

One-Step Synthesis of Stable Gold Nanoparticles on Eco-friendly Ionic Liquid

2012 ◽  
Vol 1386 ◽  
Author(s):  
P Anantha ◽  
Xiu Wang ◽  
C.C. Wong
Keyword(s):  
Gold Nanoparticles ◽  
Ionic Liquid ◽  
Metallic Nanoparticles ◽  
Thermal Evaporation ◽  
Processing Technique ◽  
Nanoparticle Dispersion ◽  
Thermal Evaporation Method ◽  
Stabilizing Agents ◽  
Transmission Electron ◽  
The Difference

ABSTRACTMetallic nanoparticles are often obtained by chemical decomposition or reactive techniques involving the extensive usage of harmful reducing or stabilizing agents. A facile green synthesis technique resulting in readily exploitable nanoparticle dispersion in ionic liquid without the use of any additional agents is reported here. 1-Propyl- 3- Methyl Imidazolium Iodide (PMIM(I)) is a non-volatile, thermally stable and non-toxic ionic liquid. This eco-friendly liquid is used as the substrate for thermal evaporation of gold to obtain stable gold nanoparticles. On being examined by Transmission Electron Microscopy the high monodispersity in their sizes was revealed. The byproduct free, ‘clean’ processing technique helps in obtaining un-contaminated particles. The thermal evaporation method used (for the generation of metallic vapor) plays a significant role in the difference in kinetics of the formation and growth of nanoparticles, unlike the widely reported sputtering technique for vapor generation. The formed particles are deposited only on the top surface of the liquid. Thus the nucleation and growth of the particles can be considered to have occurred by surface diffusion process only. A deeper investigation into the formation kinetics has the potential application for synthesizing other nanomaterials via this environmental friendly approach.

scholarly journals Green Synthesis of Gold Nanoparticles Using Polianthes tuberosa L. Floral Extract

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2370
Author(s):  
Mousa A. Alghuthaymi ◽  
Chandrasekaran Rajkuberan ◽  
Thiyagaraj Santhiya ◽  
Ondrej Krejcar ◽  
Kamil Kuča ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Metallic Nanoparticles ◽  
Antagonistic Activity ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Potential Applications ◽  
Uv Visible ◽  
Dose Dependent ◽  
Mcf 7

The developments of green-based metallic nanoparticles (gold) are gaining tremendous interest, having potential applications in health care and diagnosis. Therefore, in the present study, Polianthes tuberosa flower filtered extract was used as a reducing and stabilizing agent to synthesize gold nanoparticles (PtubAuNPs). The PtubAuNPs were extensively characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and X-ray diffraction. The antibacterial activity of PtubAuNPs was determined by the agar well diffusion method; the PtubAuNPs performed extreme antagonistic activity against the tested pathogens. Furthermore, the cytotoxicity of the PtubAuNPs was evaluated in MCF 7 cells by MTT assay. The PtubAuNPs induced toxicity in MCF 7 cells with the least concentration of 100 µg/mL in a dose-dependent method by inducing apoptosis. Overall, the study manifested that PtubAuNPs are a potent nanomaterial that can be employed as an antimicrobial and anticancer agent.

scholarly journals New Thiophene Monolayer-Protected Copper Nanoparticles: Synthesis and Chemical-Physical Characterization

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Elisabetta Foresti ◽  
Guido Fracasso ◽  
Massimiliano Lanzi ◽  
Isidoro Giorgio Lesci ◽  
Luisa Paganin ◽  
...  
Keyword(s):  
Metallic Nanoparticles ◽  
Morphological Evolution ◽  
Wide Band ◽  
Phase System ◽  
Water Medium ◽  
Copper Salts ◽  
Transmission Electron ◽  
Synthetic Reactions ◽  
Irreversible Aggregation ◽  
First Time

For the first time copper 3-(6-mercaptohexyl)thiophene-protected nanoparticles (Cu T6SH) have been synthesized by a one-phase system, utilizing anNaBH4/LiCl mixture in diglyme as the reducing reagent and avoiding water medium dissolving copper salts. The prepared nanoclusters, characterized by transmission electron microscopy (TEM), have shown a constant spherical morphology with a size dimension of 5-6 nm in diameter. After their synthesis, no morphological evolution and irreversible aggregation process has been observed after a storage inCH2Cl2at low temperature for a period up to six months long. Cu T6SH nanoparticles have been investigated by UV-Visible (UV-Vis) and Fourier transmission infrared (FTIR) spectroscopes to characterize the alkylthiophenes monolayer conformations and the particles optoelectronic properties. The UV-Vis reveals the lack of the surface plasmonic band, previously observed in Cu-nanosized clusters at about 556–570 nm, and shows a wide-band centered at 293 nm, probably due to the high-conformational surface ordering of thiophene rings on the Cu core. The results highlight the importance of the modifications ported to the well-known one-phase synthetic reactions to obtain a clear lack, even after a storage of six months, of any irreversible aggregation that has always characterized chain thiophene-protected metallic nanoparticles.

scholarly journals Biosynthesis of Silver and Gold Nanoparticles Using Aqueous Extract of Codonopsis pilosula Roots for Antibacterial and Catalytic Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Van-Dat Doan ◽  
Bao-An Huynh ◽  
Thanh-Danh Nguyen ◽  
Xuan-Thang Cao ◽  
Van-Cuong Nguyen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Aqueous Extract ◽  
Metal Ion ◽  
Metallic Nanoparticles ◽  
Ion Concentration ◽  
Gram Negative ◽  
X Ray ◽  
Codonopsis Pilosula ◽  
Vis Spectroscopy

In this study, biogenic silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by a green approach using an aqueous extract from Codonopsis pilosula (CP) roots as a reducing and stabilizing agent. The formation of CP-AgNPs and CP-AuNPs was confirmed and optimized by UV-Vis spectroscopy. The CP-AgNPs and CP-AuNPs obtained under optimum conditions of metal ion concentration, reaction temperature, and reaction time were characterized by high-resolution transition electron microscopy (HR-TEM), selected area electron diffraction (SAED) analysis, field-emission scan electron microscopy (FE-SEM), powder X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS) method. It has been found that the biosynthesized CP-AgNPs and CP-AuNPs were formed in spherical shape with an average size of 10±2.5 nm and 20±3.2 nm, respectively. The biosynthesized metallic nanoparticles exhibited selective bacterial activity against three bacterial strains including two Gram-positive bacteria of Bacillus subtilis and Staphylococcus aureus and one Gram-negative bacteria of Escherichia coli. Meanwhile, there was no antibacterial activity detected toward Gram-negative Salmonella enteritidis. CP-AgNPs and CP-AuNPs also manifested an excellent catalytic performance in the reduction of 1,4-dinitrobenzene, 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol.

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 Green Synthesis of Gold Nanoparticles using Pimenta dioica Leaves Aqueous Extract and Their Application as Photocatalyst, Antioxidant, and Antibacterial Agents

2021 ◽  
Vol 1 (2) ◽  
pp. 78-88
Author(s):  
Adewale Fadaka ◽  
Olukemi Aluko ◽  
Saartjie Awawu ◽  
Karim Theledi
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Aqueous Extract ◽  
Antibacterial Properties ◽  
Inhibitory Effect ◽  
Blue Dye ◽  
Effective Parameters ◽  
Transmission Electron ◽  
Stabilization Effect ◽  
Pimenta Dioica

Green synthesis of gold nanoparticles (AuNPs) is of particular interest due to their catalytic, antioxidant, and antibacterial properties. In this study, the aqueous extract of Pimenta dioica leaves was used to synthesize AuNPs and the effective parameters were investigated. The prepared AuNPs were characterized by various techniques including UV–Vis absorption spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Transmission Electron Microscopy (TEM), and X-ray diffractometer (XRD). The reduction and stabilization effect of the plant extract to fabricate AuNPs were explained by FTIR analysis. TEM imaging confirmed the formation of spherical-shaped AuNPs. The catalytic activity of synthesized nanoparticles was evaluated in the degradation of a Methylene Blue dye in the presence of NaBH4 as reducing agent and achieved after only two minutes. The AuNPs provided high antioxidant ability. In addition, the synthesized AuNPs showed a significant inhibitory effect against both gram-positive and gram-negative bacteria, where the zone of inhibition of 4 and 9 mm were obtained for synthesized AuNPs against S. aureus and E. coli, respectively.

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