Silver Nanoparticles - Trapping and Manipulation

2015 ◽  
Vol 832 ◽  
pp. 123-131
Author(s):  
E. Thanikaivalan ◽  
R. Jothilakshmi ◽  
P. Murugakoothan
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Optical Scattering ◽  
Trapping Effect ◽  
Plasmon Resonance Band ◽  
Transmission Electron ◽  
Resonance Band ◽  
Gradient Forces

Silver nanoparticles with different radii were synthesized using silver nitrate solution added with sodium borohydride solution at different ratios. The synthesized silver nanoparticles of radii 25.3 nm, 31 nm, 33.6 nm and 37.1 nm were characterized by transmission electron microscopy (TEM) and UV-vis absorption spectroscopy. The synthesized silver nanoparticles exhibit spherical morphology for all radii. The silver nanoparticles exhibit the plasmon resonance band between 390 nm – 400 nm. The optical trapping effect of Gaussian beam acting on a silver nanoparticle in Rayleigh regime was studied. The optical scattering and optical gradient forces were calculated for silver nanoparticles of different radii.

scholarly journals Antimicrobial Bacterial Cellulose-Silver Nanoparticles Composite Membranes

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Hernane S. Barud ◽  
Thaís Regiani ◽  
Rodrigo F. C. Marques ◽  
Wilton R. Lustri ◽  
Younes Messaddeq ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Bacterial Cellulose ◽  
Nitrate Solution ◽  
Composite Membranes ◽  
Silver Nitrate Solution ◽  
Complexing Agent ◽  
X Ray Diffraction ◽  
Gram Positive Bacteria ◽  
Transmission Electron

Antimicrobial bacterial cellulose-silver nanoparticles composite membranes have been obtained by“in situ”preparation of Ag nanoparticles from hydrolytic decomposition of silver nitrate solution using triethanolamine as reducing and complexing agent. The formation of silver nanoparticles was evidenced by the X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and absorption in the UV-Visible (350 nm to 600 nm). Thermal and mechanical properties together with swelling behavior for water were considered. TEA concentration was observed to be important in order to obtain only Ag particles and not a mixture of silver oxides. It was also observed to control particle size and amount of silver contents in bacterial cellulose. The composite membranes exhibited strong antimicrobial activity against Gram-negative and Gram-positive bacteria.

scholarly journals Ecofriendly Synthesis of Silver Nanoparticles from Garden Rhubarb (Rheum rhabarbarum)

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Palem Ramasubba Reddy ◽  
Shimoga D. Ganesh ◽  
Nabanita Saha ◽  
Oyunchimeg Zandraa ◽  
Petr Sáha
Keyword(s):  
Silver Nanoparticles ◽  
Silver Ions ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Plasmon Resonance Band ◽  
Transmission Electron ◽  
Resonance Band ◽  
Crystalline Nature

Bioreduction of silver ions following one pot process is described to achieveRheum rhabarbarum(RR) based silver nanoparticles (SNPs) which is termed as “RR-SNPs.” The Ultraviolet–visible spectroscopy (UV–vis) confirms the characteristic surface plasmon resonance band for RR-SNPs in the range of 420–460 nm. The crystalline nature of SNPs was confirmed by X-ray diffraction (XRD) peaks at 38.2°, 45.6°, 64.2°, and 76.8°. Transmission electron microscopy (TEM) and scanning electronic microscopy (SEM) confirm the shape of synthesized SNPs. They are roughly spherical but uniformly distributed, and size varies from 60 to 80 nm. These biogenic SNPs show persistent zeta potential value of 34.8 mV even after 120 days and exhibit potent antibacterial activity in presence ofEscherichia coli(CCM 4517) andStaphylococcus aureus(CCM 4516). In addition, cytotoxicity of RR-SNPs againstin vitrohuman epithelial carcinoma (HeLa) cell line showed a dose-response activity. The lethal concentration (LC50) value was found to be 28.5 μg/mL for RR-SNPs in the presence of HeLa cells. These findings help us to evaluate their appropriate applications in the field of nanotechnology and nanomedicine.

scholarly journals Evaluation of the Cytotoxic Activity of Biosynthesized Silver Nanoparticles Using Berberis vulgaris Leaf Extract

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Akbar Safipour Afshar ◽  
Fatemeh Saeid Nematpour
Keyword(s):  
Silver Nanoparticles ◽  
Cytotoxic Activity ◽  
Leaf Extract ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
X Ray Diffraction ◽  
Berberis Vulgaris ◽  
Transmission Electron ◽  
Cancerous Cells ◽  
Mcf 7

Background: Recently, due to the numerous applications of silver nanoparticles (AgNPs) in industry, various routes to synthesize them have been developed. Objectives: The current study was aimed at synthesizing silver nanoparticles by the leaf extract of Berberis vulgaris and evaluating the cytotoxic effects on human breast cancer MCF-7 cell line. Methods: The leaf extract of Berberis vulgaris and silver nitrate solution were used to synthesize silver nanoparticles. Ultraviolet (UV)-visible, Fourier-transform infrared, and X-ray diffraction analysis spectroscopy and transmission electron microscopy methods were used to characterize and confirm the nanoparticles’ synthesis. The cytotoxic activity of synthesized nanoparticles (0, 5,10, 20, 40 µg/mL) was also studied by MTT assay. Results: The results showed that Ag nanoparticles were polydisperse and spherical in shape and had a size of about 19.9 nm. Silver nanoparticles reduced the growth of cancerous cells based on time and concentration. The IC50 for MCF-7 cells at 48 hours was 20.27 µg/mL. Conclusions: The findings showed that synthesized nanoparticles have an appropriate cytotoxic effect on cancer cells. This impact may be due to the production of free radicals through the release of Ag ions.

scholarly journals Investigating the Possibility of Green Synthesis of Silver Nanoparticles Using Vaccinium arctostaphlyos Extract and Evaluating Its Antibacterial Properties

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Sedighe Khodadadi ◽  
Nafiseh Mahdinezhad ◽  
Bahman Fazeli-Nasab ◽  
Mohammad Javad Heidari ◽  
Baratali Fakheri ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Ftir Spectroscopy ◽  
Aqueous Extract ◽  
Nitrate Solution ◽  
Antibacterial Properties ◽  
Silver Nitrate Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy

Objective. Vaccinium genus plants have medicinal value, of which Vaccinium arctostaphylos (Caucasian whortleberry or Qare-Qat in the local language) is the only available species in Iran. Public tendency to use herbal remedies and natural products such as synthesized nanoparticles is increasing due to the proof of the destructive side effects of chemical drugs. Nanosilver products have been effective against more than 650 microbe types. This study was aimed at assessing the possibility of green synthesis of silver nanoparticles using Vaccinium arctostaphylos aqueous extract and at evaluating its antibacterial properties, as well. Materials and Methods. In order to synthesize silver nanoparticles, different volumes of Vaccinium arctostaphylos aqueous extract (3, 5, 10, 15, and 30 ml) were assessed with different silver nitrate solution concentrations (0.5, 1, 3, 5, and 10 mM) and different reaction time durations (1, 3, 5, 10, and 20 minutes) at room temperature using a rotary shaker with a speed of 150 rpm. Ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction analysis (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) were carried out. The antibacterial activity of the aqueous extract and the synthesized nanoparticles was evaluated, as well. Results. Silver nanoparticle formation process was confirmed with XRD analysis, transmission electron microscopy (TEM), and FTIR spectroscopy. The UV-Vis spectroscopy of silver colloidal nanoparticles showed a surface plasmon resonance peak at 443 nm under optimal conditions (3 ml aqueous extract volume, 1 mM silver nitrate solution concentration, and 3 min reaction time under sunlight exposure). The reduction of silver ions to silver nanoparticles in solution was confirmed, as well. Based on X-ray diffraction analysis, the size of silver nanoparticles was in the range of 7-16 nm. TEM images showed an even distribution of silver nanoparticles, with a spherical shape. FTIR spectroscopy demonstrated the presence of different functional groups of oxygenated compounds such as carboxyl, hydroxyl, and nitrogenous groups. The antibacterial properties of the synthesized nanoparticles were confirmed. Conclusion. The synthesized nanoparticles showed more antibacterial properties against gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) than gram-negative ones (Escherichia coli and Salmonella enteritidis).

scholarly journals Corylus avellana leaf extract-mediated green synthesis of antifungal silver nanoparticles using microwave irradiation and assessment of their properties

2021 ◽  
Vol 10 (1) ◽  
pp. 606-613
Author(s):  
Mahsa Eshghi ◽  
Asa Kamali-Shojaei ◽  
Hamideh Vaghari ◽  
Yahya Najian ◽  
Zahra Mohebian ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Microwave Irradiation ◽  
Silver Nitrate ◽  
Leaf Extract ◽  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Corylus Avellana ◽  
Transmission Electron ◽  
Minimum Particle Size

Abstract Due to high antimicrobial activity against numerous microorganisms, silver nanoparticles (AgNPs) are being utilized in various areas. Microwave-accelerated AgNPs synthesis using Corylus avellana leaf extract was evaluated. Based on randomly central composite design, 13 mixture solutions containing different amounts of the prepared extract (0.10–0.90 mL) and 1 mM silver nitrate solution (15–25 mL) were prepared and exposed to microwave irradiation for 180 s. Response surface methodology was utilized to evaluate the effects of the two independent variables on particle size and concentration of the synthesized AgNPs, as manifested in the place of broad emission peak (λ max) and its absorbance unit, respectively. Fourier transform infrared spectroscopy analysis indicated that the two hydroxyl and carboxylic acid functional groups with reducing activity existed in the prepared extract. Dynamic light scattering and transmission electron microscopy analyses revealed that the formed spherical AgNPs using optimum amounts of C. avellana leaf extract (0.9 mL) and 1 mM silver nitrate solution (25 mL) had minimum particle size (103.5 nm) and polydispersity index (PDI) (0.209), and maximum concentration (140 ppm) and zeta potential (−21.8 mV). Results indicated that the formed AgNPs had high fungicidal effects against the spoiled fungi of Colletotrichum coccodes and Penicillium digitatum.

scholarly journals Microwave-assisted green synthesis of silver nanoparticles using dried extracts of Chlorella vulgaris and antibacterial activity studies

2020 ◽  
Vol 9 (1) ◽  
pp. 283-293
Author(s):  
Milad Torabfam ◽  
Meral Yüce
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Chlorella Vulgaris ◽  
Metallic Nanoparticles ◽  
Nitrate Solution ◽  
Spherical Shape ◽  
Silver Nitrate Solution ◽  
Spectroscopy Analysis ◽  
Bacterial Diseases ◽  
Serovar Typhimurium

AbstractGreen synthesis of metallic nanoparticles (NPs) is acquiring considerable attention due to its environmental and economic superiorities over other methods. This study describes the practical synthesis of silver nanoparticles (AgNPs) through the reduction of silver nitrate solution using an algal source, Chlorella vulgaris, as the reducing as well as the stabilizing agent. The energy required for this synthesis was supplied by microwave radiation. The ultraviolet-visible spectroscopy exhibited a single peak related to the surface plasmon absorbance of AgNPs at 431 nm. The AgNPs with high stability (a zeta potential of −17 mV), hydrodynamic size distribution of 1–50 nm, and mostly spherical shape were obtained through a 10 min process. Fourier transform infrared spectroscopy analysis revealed that several functional groups, including carbonyl groups of C. vulgaris, play a significant role in the formation of functional NPs. Antibacterial features of the produced AgNPs were verified against those of Salmonella enterica subsp. enterica serovar typhimurium and Staphylococcus aureus, demonstrating a considerable growth inhibition at increasing concentrations of the NPs. As a result, the formed AgNPs can be used as a promising agent against bacterial diseases.

Preparation of Triangular Silver Nanoparticles Using Polyvinyl Pyrrolidone with Different Concentration

2013 ◽  
Vol 873 ◽  
pp. 206-210
Author(s):  
Kai Li ◽  
Rao Fu ◽  
Qing Ran Gao ◽  
Ai Wei Tang ◽  
Ying Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Silver Nanoparticles ◽  
Driving Force ◽  
Ostwald Ripening ◽  
Polyvinyl Pyrrolidone ◽  
Protective Agent ◽  
Ag Nps ◽  
Transmission Electron ◽  
Uv Visible

This paper continues our previous work on preparation of triangular silver nanoparticles. The method proceeds with reaction of silver nitrate with hydrazine hydrate in the presence of polyvinyl pyrrolidone in aqueous solution. Effects of the concentration of PVP on the morphologies of Ag NPs were systematically investigated. The obtained Ag NPs were characterized by transmission electron microscopy and UV-visible spectrophotometer. The results showed that, triangular Ag NPs with edge lengths in the range of 50-200 nm were obtained using PVP as protective agent with lower concentration. As the concentration of PVP increased, spherical Ag NPs with their sizes about 6.2 nm were prepared and triangular Ag NPs were not obtained. The formation mechanism of triangular Ag NPs has been studied. Ostwald ripening is the driving force on the conversion of spherical Ag NPs to triangular Ag NPs in the presence of PVP.

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.

Sign in / Sign up

Export Citation Format

Share Document