scholarly journals Green Synthesis of Hydroxyethyl Cellulose-Stabilized Silver Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
M. A. El-Sheikh ◽  
S. M. El-Rafie ◽  
E. S. Abdel-Halim ◽  
M. H. El-Rafie
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Colloidal Solution ◽  
Hydroxyethyl Cellulose ◽  
Synthesis Process ◽  
Reaction Conditions ◽  
Oh Groups ◽  
Stabilizing Agents ◽  
Transmission Electron ◽  
Optimum Reaction

Green synthesis aims to minimize the use of unsafe reactants and maximize the efficiency of synthesis process. These could be achieved by using environmentally compassionate polymers and nontoxic chemicals. Hydroxyethyl cellulose (HEC), an ecofriendly polymer, was used as both reducing and stabilizing agents in the synthesis of stable silver nanoparticles, while silver nitrate was used as a precursor and water as a solvent. The formation of silver nanoparticles was assessed by monitoring UV-vis spectra of the silver colloidal solution. The size of the nanoparticles was measured using transmission electron microscope (TEM). Reaction kinetics was followed by measuring the absorbance of silver colloidal solution at different time intervals. Optimum reaction conditions revealed that the highest absorbance was obtained using HEC : AgNO3 of 1.5 : 0.17 (g/100 cm3) at 70°C for 120 min at pH 12. The Ag0 nanoparticles colloidal solution so obtained (1000 ppm) were found stable in aqueous solution over a period of six months at room temperature (°C). The sizes of these nanoparticles were found in the range of 11–60 nm after six months of storing. FTIR spectra confirmed the interaction of both the aldehyde and OH groups in the synthesis and stabilization of silver nanoparticles.

scholarly journals On the Ability of Low Molecular Weight Chitosan Enzymatically Depolymerized to Produce and Stabilize Silver Nanoparticles

Biomimetics ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 21 ◽  
Author(s):  
Inmaculada Aranaz ◽  
Carolina Castro ◽  
Angeles Heras ◽  
Niuris Acosta
Keyword(s):  
Molecular Weight ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Noble Metals ◽  
Chemical Properties ◽  
Biological Properties ◽  
Natural Polymers ◽  
Silver Surface ◽  
Stabilizing Agents ◽  
Transmission Electron

Silver nanoparticles (AgNPs) are of great interest due to their antimicrobial, optical and catalytical properties. Green synthesis of AgNPs is fundamental for some applications such as biomedicine and catalysis. Natural polymers, such as chitosan, have been proposed as reducing and stabilizing agents in the green synthesis of AgNPs. Physico-chemical properties of chitosan have a great impact on its technological and biological properties. In this paper, we explore the effect of chitosan molecular weight (Mw) on the thermal AgNPs production using two sample sets of low Mw chitosans (F1 > 30 kDa, F2: 30–10 kDa and F3: 10–5 kDa) produced by enzymatic depolymerization of a parent chitosan with chitosanase and lysozyme. Both polymer sets were able to effectively reduce Ag+ to Ag0 as the presence of the silver surface plasmon resonance (SRP) demonstrated. However, the ability to stabilize the nanoparticles depended not only on the Mw of the polymer but particularly on the polymer pattern which was determined by the enzyme used to depolymerize the parent chitosan. Low Mw chitosan samples produced by lysozyme were more effective than those produced by chitosanase to stabilize the AgNPs and smaller and less polydisperse nanoparticles were visualized by transmission electron microscopy (TEM). With some polymer sets, more than 80% of the AgNPs produced were lower than 10 nm which correspond to quantum dots. The preparation method described in this paper is general and therefore, it may be extended to other noble metals, such as palladium, gold or platinum.

scholarly journals Metallic nanoformulations: Green synthetic approach for advanced drug delivery

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Afreen Usmani 1 ◽  
Pragyandip P Dash 2 ◽  
Anuradha Mishra 1
Keyword(s):  
Drug Delivery ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Plant Extract ◽  
Plant Extracts ◽  
Synthesis Process ◽  
Synthetic Approach ◽  
Anticancer Activities ◽  
Stabilizing Agents ◽  
Whole Plant

An important reason for investigation using plants for nanotechnological research is due to their easy availability as well as applications in various ailments. Silver nanoformulation can be synthesized using whole plant extract or bioactive of that particular plant. In addition, plant extracts or bioactive of the plant may act both as reducing agents and stabilizing agents in the synthesis process of nanoformulation. The therapeutic effect of plant extract is hindered because of its instability, poor solubility, and low bioavailability. So, nowadays, researches have been carried out for improving all these properties including sustainability through silver nanotechnological approach. The major advantage of green synthesis using plant extracts is that, organic solvents and other excipients are not used because the plant phytochemicals are involved directly in the reduction of the ions and formation of silver nanoparticles. The present review provides an updated knowledge on mechanism of green synthesis of silver nanoparticle and their mechanism of action as antibacterial and anticancer activities.

scholarly journals A Novel Photosynthesis of Carboxymethyl Starch-Stabilized Silver Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
M. A. El-Sheikh
Keyword(s):  
Silver Nanoparticles ◽  
Room Temperature ◽  
Colloidal Solution ◽  
Synthesis Method ◽  
Silver Ions ◽  
Water Soluble ◽  
Synthesis Process ◽  
Carboxymethyl Starch ◽  
Round Shape ◽  
First Time

The water soluble photoinitiator (PI) 4-(trimethyl ammonium methyl) benzophenone chloride is used for the first time in the synthesis of silver nanoparticles (AgNPs). A new green synthesis method involves using PI/UV system, carboxymethyl starch (CMS), silver nitrate, and water. A mechanism of the reduction of silver ions to AgNPs by PI/UV system as well as by the newly born aldehydic groups was proposed. The synthesis process was assessed by UV-vis spectra and TEM of AgNPs colloidal solution. The highest absorbance was obtained using CMS, PI and AgNO3concentrations of 10 g/L, 1 g/L, and 1 g/L, respectively; 40°C; 60 min; pH 7; and a material : liquor ratio 1 : 20. AgNPs so-obtained were stable in aqueous solution over a period of three weeks at room temperature (~25°C) and have round shape morphology. The sizes of synthesized AgNPs were in the range of 1–21 nm and the highest counts % of these particles were for particles of 6–10 and 1–3 nm, respectively.

Optimization of Green Synthesis Approach of Silver Nanoparticles Using Indonesian Wild Honey

2021 ◽  
Vol 891 ◽  
pp. 111-115
Author(s):  
Maradhana Agung Marsudi ◽  
Farah Fitria Sari ◽  
Pandu Mauliddin Wicaksono ◽  
Adinda Asmoro ◽  
Arif Basuki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particle Count ◽  
Transmission Electron ◽  
Nitrate Precursor ◽  
Synthesis Approach

In this work, silver nanoparticles have been successfully synthesized using simple and environmentally friendly ‘green synthesis’ method using Indonesian wild honey as mediator. Particle count and size can be optimized by varying the silver nitrate precursor and honey concentration, with the help of sodium hydroxide as pH regulator. Based on X-ray diffraction (XRD) result, crystalline structure of Ag has been confirmed in sample with impurities from AgCl. Based on dynamic light scattering (DLS) and transmission electron microscopy (TEM) results, it was found that the smallest average particles size of AgNPs (117.5 nm from DLS and 11.1 nm from TEM) was obtained at sample with 5% w/v of honey and 0.5 mM of AgNO3.

scholarly journals Microwave-Assisted Green Synthesis of Silver Nanoparticles Using Juglans regia Leaf Extract and Evaluation of Their Physico-Chemical and Antibacterial Properties

Antibiotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 68 ◽  
Author(s):  
Mahsa Eshghi ◽  
Hamideh Vaghari ◽  
Yahya Najian ◽  
Mohammad Najian ◽  
Hoda Jafarizadeh-Malmiri ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Juglans Regia ◽  
Antibacterial Properties ◽  
Infrared Analysis ◽  
Ag Nps ◽  
Stabilizing Agents ◽  
Agno3 Solution ◽  
Transmission Electron ◽  
Vis Spectroscopy

Silver nanoparticles (Ag NPs) were synthesized using Juglans regia (J. regia) leaf extract, as both reducing and stabilizing agents through microwave irradiation method. The effects of a 1% (w/v) amount of leaf extract (0.1–0.9 mL) and an amount of 1 mM AgNO3 solution (15–25 mL) on the broad emission peak (λmax) and concentration of the synthesized Ag NPs solution were investigated using response surface methodology (RSM). Fourier transform infrared analysis indicated the main functional groups existing in the J. regia leaf extract. Dynamic light scattering, UV-Vis spectroscopy and transmission electron microscopy were used to characterize the synthesized Ag NPs. Fabricated Ag NPs with the mean particle size and polydispersity index and maximum concentration and zeta potential of 168 nm, 0.419, 135.16 ppm and −15.6 mV, respectively, were obtained using 0.1 mL of J. regia leaf extract and 15 mL of AgNO3. The antibacterial activity of the fabricated Ag NPs was assessed against both Gram negative (Escherichia coli) and positive (Staphylococcus aureus) bacteria and was found to possess high bactericidal effects.

Citrate Stabilized Silver Nanoparticles

2011 ◽  
Vol 3 (3) ◽  
pp. 15-28 ◽  
Author(s):  
Nabraj Bhattarai ◽  
Subarna Khanal ◽  
Pushpa Raj Pudasaini ◽  
Shanna Pahl ◽  
Dulce Romero-Urbina
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Colloidal Solution ◽  
Measurement Techniques ◽  
Structural Defects ◽  
Potential Measurement ◽  
Transmission Electron

Citrate stabilized silver (Ag) colloidal solution were synthesized and characterized for crystallographic and surface properties by using transmission electron microscopy (TEM) and zeta potential measurement techniques. TEM investigation depicted the size of Ago ranges from 5 to 50 nm with smaller particles having single crystal structure while larger particles with structural defects (such as multiply twinned, high coalescence and Moire patterns). ?-potential measurement confirms the presence of Ag+ in nAg stock solution. The shift in ?-potential measurement by +25.1 mV in the filtered solution suggests the presence of Ag+ in Ago nanoparticles.

Green Synthesis of Spherical Shaped Silver Nanoparticles Using Allium cepa Leaves Extract and its Photocatalytic Activity

2019 ◽  
Vol 962 ◽  
pp. 57-62
Author(s):  
Rohayu Jusoh ◽  
Nur Hidayatul Nazirah Kamarudin ◽  
Nur Syahirah Kamarudin ◽  
Nuramira Fateha Sukor
Keyword(s):  
Silver Nanoparticles ◽  
Allium Cepa ◽  
Active Species ◽  
Total Phenolic ◽  
Dichlorophenoxyacetic Acid ◽  
Flavonoid Content ◽  
Stabilizing Agents ◽  
Transmission Electron ◽  
Infrared Spectrometer ◽  
Potential Use

Spherical silver nanoparticles (AgNPs) (5–15 nm) were synthesized by a simple electrochemical method at room temperature using Allium Cepa (AC) leaves extract. AC leaves extract that acts as a reducing and stabilizing agent is capable of producing AgNPs without any agglomeration. The phytochemical properties of the leaves extract including total phenolic content, total flavonoid content, and its active species were studied. The crystallinity, morphology, and functional characteristics of the AgNPs were analyzed using an X–ray diffractometer, a transmission electron microscope, and a Fourier–transform infrared spectrometer, respectively. The characterization results verified the contribution of phenolic acids and flavonoids in reduction of Ag+ to metallic AgNPs and also in stabilization of the AgNPs. The catalytic activity of the AgNPs was tested towards the photodegradation of 2, 4–dichlorophenoxyacetic acid (2,4–D) herbicide, in which showing a remarkable degradation performance of 80%. The results provide strong evidence to support the potential use of AC leaves extract to act as green reducing and stabilizing agents as well as a green electrolyte to synthesize well–scattered spherical shaped AgNPs.

Short Review: The Effect of Reaction Conditions on Plant-Mediated Synthesis of Silver Nanoparticles

2018 ◽  
Vol 917 ◽  
pp. 145-151 ◽  
Author(s):  
Nur Syazana Jalani ◽  
Sharifah Zati-Hanani ◽  
Yi Peng Teoh ◽  
Rozaini Abdullah
Keyword(s):  
Silver Nanoparticles ◽  
Bioactive Compounds ◽  
Short Review ◽  
Natural Source ◽  
Hazardous Chemicals ◽  
Reaction Conditions ◽  
Physical Methods ◽  
Stabilizing Agents ◽  
Environmental Friendly ◽  
Source Plant

Recently, interest in plant-mediated synthesis of the silver nanoparticles (AgNPs) is growing among researchers and till now the potential of different plants is still further explored to synthesize nanoparticles. Conventionally, AgNPs are synthesized using chemical and physical methods. However, these methods involve use of toxic and hazardous chemicals which are harmful to health and environment. Therefore, plant-mediated synthesis has been used as environmental friendly alternative to overcome the limitation of conventional methods. The bioactive compounds in plant acts as natural reducing and stabilizing agents which help to increase the rate of synthesis and stabilization of synthesized nanoparticles. Besides, the nanoparticles synthesized using plants are reported to be more stable and the rate of synthesis is much faster compared to other methods. This review focuses on the biosynthesis of AgNPs using plant as natural source plant and the effect of reaction conditions are summarised and discussed.

scholarly journals Green synthesis and characterization of cuprous oxide nanoparticles in presence of a bio-surfactant

2014 ◽  
Vol 32 (4) ◽  
pp. 702-708 ◽  
Author(s):  
M. Behera ◽  
G. Giri
Keyword(s):  
Green Synthesis ◽  
Photoelectron Spectroscopy ◽  
Broad Band ◽  
X Ray Diffraction ◽  
Oh Groups ◽  
X Ray ◽  
Transmission Electron ◽  
Fcc Lattice ◽  
Perennial Shrub ◽  
A Charge

AbstractHerein, we report a facile green synthesis of Cu2O nanoparticles (NPs) using copper sulfate as precursor salt and hydrazine hydrate as reducing agent in presence of bio-surfactant (i.e. leaves extract of arka — a perennial shrub) at 60 to 70 °C in an aqueous medium. A broad band centered at 460 nm in absorption spectrum reveals the formation of surfactant stabilized Cu2O NPs. X-ray diffraction pattern of the surfactant stabilized NPs suggests the formation of only Cu2O phase in assistance of a bio-surfactant with the crystallite size of ∼8 nm. A negative zeta potential of −12 mV at 8.0 pH in surfactant stabilized Cu2O NPs hints non-bonding electron transfer from O-atom of saponin to the surface of NP. Red-shift in the vibrational band (Cu-O stretching) of Cu2O from 637 cm−1 to 640 cm−1 in presence of bio-surfactant suggests an interfacial interaction between NPs and O-atoms of -OH groups of saponin present in the plant (i.e. Calotropis gigantean) extract. From X-ray photoelectron spectroscopy spectra, a decrease in binding energy of both 2p3/2 and 2p1/2 bands in Cu2O with saponin molecules as compared to bulk Cu atom reveals a charge transfer interaction between NP and saponin surfactant molecules. Transmission electron microscopy images show crystalline nature of Cu2O NPs with an fcc lattice.

scholarly journals Microwave Assisted Rapid and Green Synthesis of Silver Nanoparticles Using a Pigment Produced byStreptomyces coelicolorklmp33

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Deene Manikprabhu ◽  
K. Lingappa
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Streptomyces Coelicolor ◽  
Biological Synthesis ◽  
Toxic Substances ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
Major Drawback ◽  
Transmission Electron ◽  
Uv Visible

Traditional synthesis of silver nanoparticles using chemical methods produces toxic substances. In contrast biological synthesis is regarded as a safe and nontoxic process but the major drawback of biological synthesis is, this process is slow. In the present investigation, we developed a rapid and green synthesis of silver nanoparticles employing a pigment produced byStreptomyces coelicolorklmp33 in just 90 s. The silver nanoparticles were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The biobased synthesis developed in this method is a safe, rapid, and appropriate way for bulky synthesis of silver nanoparticles.

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