scholarly journals Green Synthesis of Metal Nanostructures and Its Nonlinear Optical Properties

2021 ◽  
Author(s):  
Emusani Ramya
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Nonlinear Optical ◽  
Electric Dipole Transition ◽  
Metal Nanostructures ◽  
Ag Nps ◽  
Nonlinear Optical Susceptibility ◽  
Visible Absorption ◽  
Luminescence Enhancement ◽  
Silver Nps

Simple green synthesis of metal nanoparticles (Ag NPs) was prepared by using Raphanussativus leaf extract. This extract acts as reduce and stabilizing agent. The formation of silver NPs was confirmed and characterized by XRD, UV–visible absorption spectrum, TEM, and FTIR. The luminescence enhancement and quenching of Eu3+and Sm3+ ions were observed in the presence of silver NPs. The luminescence enhancement is owing to arise in the electric-dipole transition with alteration of the field around Ln3+ ions. Nonlinear studies in femtosecond (fs) and picosecond (ps) time scales have been studied by using the Z-scan technique. Third-order nonlinear optical susceptibility of silver nanoparticles was obtained with Degenerate Four-Wave Mixing (DFWM) in the fs regime. The lifetimes of lanthanum complexes were increased by the concentration of silver NPs and decreased for further silver. The high enhanced luminescence and nonlinear studies of green synthesized silver nanoparticles can be used in optics and bio applications.

scholarly journals Silver nanoparticles: Green Synthesis and Their Antibacterial efficiency

2021 ◽  
Vol 59 (2) ◽  
pp. 214
Author(s):  
Dung Ngo Thanh ◽  
Nguyet Ha Minh ◽  
Tam Le Thi Thanh ◽  
Lu Le Trong
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Silver Nitrate ◽  
Tannic Acid ◽  
Ag Nanoparticles ◽  
Sodium Citrate ◽  
Reducing Agents ◽  
Ag Nps ◽  
Silver Nps

In this study, silver nanoparticles were synthesized from aqueous silver nitrate through a simple and eco-friendly route using a combination of two reducing agents: sodium citrate and tannic acid. By this method, the obtained Ag nanoparticles (NPs) were stable within the studied period of six months. Besides, both TEM images and UV-Vis results showed that the size of silver NPs could be controlled by changing the concentration of tannic acid. The antibacterial ability of Ag NPs with different sizes were also examined. In detail, the smaller the Ag NPs were, the more efficient their antibacterial activity was.

scholarly journals GREEN SYNTHESIS OF SILVER NANOPARTICLES USING GRAPE POMACE WASTE FOR THE DEGRADATION OF PHARMACEUTICALS DRUGS AND ORGANIC DYES

2019 ◽  
pp. 37-42
Author(s):  
Margarita Skiba ◽  
Viktoria Vorobyova ◽  
Oleksandr Pivovarov
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Metallic Nanoparticles ◽  
Average Particle Size ◽  
Silver Ions ◽  
Grape Pomace ◽  
Chemical Extraction ◽  
Average Particle ◽  
Ag Nps ◽  
Visible Absorption

The green synthesis of metallic nanoparticles paved the way to improve and protect the environment bydecreasing the use of toxic chemicals. A simple and eco-friendly method for silver nanoparticles (AgNPs) synthesis employing the aqueous extract obtained from grape pomace by plasma-chemical extraction technique was developed. The reduction of silver ions in solution was monitored using UV–visible absorption spectroscopy. The synthesised nanoparticles were characterised using scaning electron microscopy (SEM) and dynamic light scattering measurement (DLS). The sizes of the spherical silver particles were found to be in the range of 27–33 nm. The effect of silver ions concentrations on the synthesis of silver nanoparticles and average particle size was investigated. As-prepared Ag NPs had an excellent catalytic activity as a catalyst for the degradation of ibuprofen, which was carried out in 50 s. The current findings are equally extendable for safeguarding the aquatic environment against the pollution caused by drugs and microbial activity via a facile, highly economical, rapid and efficient reduction/degradation method based on the catalytic potential of Ag NPs. The report emphasizes the effect of the size of silver nanoparticles on the degradation rate of hazardous dyes - methyl blue by NaBH4..

scholarly journals Single-Step Green Synthesis of Highly Concentrated and Stable Colloidal Dispersion of Core-Shell Silver Nanoparticles and Their Antimicrobial and Ultra-High Catalytic Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1007
Author(s):  
Azam Ali ◽  
Mariyam Sattar ◽  
Fiaz Hussain ◽  
Muhammad Humble Khalid Tareen ◽  
Jiri Militky ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Tannic Acid ◽  
Rate Constant ◽  
Catalytic Properties ◽  
Colloidal Dispersion ◽  
Alkaline Condition ◽  
Core Shell ◽  
Average Particle ◽  
Ag Nps

The versatile one-pot green synthesis of a highly concentrated and stable colloidal dispersion of silver nanoparticles (Ag NPs) was carried out using the self-assembled tannic acid without using any other hazardous chemicals. Tannic acid (Plant-based polyphenol) was used as a reducing and stabilizing agent for silver nitrate in a mild alkaline condition. The synthesized Ag NPs were characterized for their concentration, capping, size distribution, and shape. The experimental results confirmed the successful synthesis of nearly spherical and highly concentrated (2281 ppm) Ag NPs, capped with poly-tannic acid (Ag NPs-PTA). The average particle size of Ag NPs-PTA was found to be 9.90 ± 1.60 nm. The colloidal dispersion of synthesized nanoparticles was observed to be stable for more than 15 months in the ambient environment (25 °C, 65% relative humidity). The synthesized AgNPs-PTA showed an effective antimicrobial activity against Staphylococcus Aureus (ZOI 3.0 mM) and Escherichia coli (ZOI 3.5 mM). Ag NPs-PTA also exhibited enhanced catalytic properties. It reduces 4-nitrophenol into 4-aminophenol in the presence of NaBH4 with a normalized rate constant (Knor = K/m) of 615.04 mL·s−1·mg−1. For comparison, bare Ag NPs show catalytic activity with a normalized rate constant of 139.78 mL·s−1·mg−1. Furthermore, AgNPs-PTA were stable for more than 15 months under ambient conditions. The ultra-high catalytic and good antimicrobial properties can be attributed to the fine size and good aqueous stability of Ag NPs-PTA. The unique core-shell structure and ease of synthesis render the synthesized nanoparticles superior to others, with potential for large-scale applications, especially in the field of catalysis and medical.

scholarly journals Antibacterial activity of royal jelly-mediated green synthesized silver nanoparticles

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Susanna Gevorgyan ◽  
Robin Schubert ◽  
Mkrtich Yeranosyan ◽  
Lilit Gabrielyan ◽  
Armen Trchounian ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Royal Jelly ◽  
Fluorescence Emission ◽  
Spherical Particles ◽  
Ag Nps ◽  
Gram Negative ◽  
Green Synthesized Silver Nanoparticles ◽  
Higher Sensitivity

AbstractThe application of green synthesis in nanotechnology is growing day by day. It’s a safe and eco-friendly alternative to conventional methods. The current research aimed to study raw royal jelly’s potential in the green synthesis of silver nanoparticles and their antibacterial activity. Royal jelly served as a reducing and oxidizing agent in the green synthesis technology of colloidal silver nanoparticles. The UV–Vis maximum absorption at ~ 430 nm and fluorescence emission peaks at ~ 487 nm confirmed the presence of Ag NPs. Morphology and structural properties of Ag NPs and the effect of ultrasound studies revealed: (i) the formation of polydispersed and spherical particles with different sizes; (ii) size reduction and homogeneity increase by ultrasound treatment. Antibacterial activity of different concentrations of green synthesized Ag NPs has been assessed on Gram-negative S. typhimurium and Gram-positive S. aureus, revealing higher sensitivity on Gram-negative bacteria.

scholarly journals Glucuronoxylan-mediated silver nanoparticles: green synthesis, antimicrobial and wound healing applications

RSC Advances ◽  
2017 ◽  
Vol 7 (68) ◽  
pp. 42900-42908 ◽  
Author(s):  
Gulzar Muhammad ◽  
Muhammad Ajaz Hussain ◽  
Muhammad Amin ◽  
Syed Zajif Hussain ◽  
Irshad Hussain ◽  
...  
Keyword(s):  
Wound Healing ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Biological Applications ◽  
Ag Nps

Hydrogel forming polysaccharides are attracting attention for the design of diverse nature silver nanoparticles (Ag NPs) with potential biological applications.

scholarly journals Green Synthesis of Silver Nanoparticles Using Raw Fruit Extract of Mimusops elengi and their Antimicrobial Study

2020 ◽  
Vol 11 (3) ◽  
pp. 10040-10051
Keyword(s):  
Green Synthesis ◽  
Colloidal Stability ◽  
Low Cost ◽  
Antimicrobial Activities ◽  
Health Food ◽  
Ag Nps ◽  
Fruit Extract ◽  
Silver Nps ◽  
Mimusops Elengi ◽  
Bacteria And Fungi

These days, nanoparticles are being considered as nano-antibiotics because of their execution of antimicrobial activities towards a broad range of microbes. Nanoparticles are used in industrial products, health, food, space, and cosmetics;thus, researchers need for a green, ecofriendly, and low-cost approach to synthesize it. Green synthesis is such an approach of synthesizing NPs using microorganisms and plants, which is free of additional impurities. We used Mimusops elengi Linn. raw fruit extract in water to reduce the silver nitrate salt to produce silver NPs. The samples were characterized using various instrumental techniques. Broadband known as Surface Plasmon Resonance found near 450 nm in the absorption spectrum shows the formation of Ag NPs. NPs with average hydrodynamic diameters in the ranges 20-300 nm were detected from DLS study having negative zeta potential value (varies between - 25.8 to 15.8 mV), which suggests that as NPs surface is charged, it provides colloidal stability to the NPs in a liquid medium. FTIR study reveals that an increase in the intensity of some of the vibrational band with NP-content is due to the adsorption of some molecules on the surface of NPs. XRD pattern shows that NPs have an fcc structure. Samples were tested to have capabilities to kill both bacteria and fungi.

scholarly journals Nanocatalytic Activity of Silver Nanoparticles (Ag-Nps) Fabricated using Camellia sinensis (Linn) Tender Leaf Extract and their Characterization

2020 ◽  
Vol 2 (1) ◽  
pp. 24
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Pancreatic Enzyme ◽  
Alpha Amylase ◽  
Assay Method ◽  
Ag Nps ◽  
Visible Absorption ◽  
Biological Reduction ◽  
Vis Spectroscopy ◽  
Uv Visible

Silver nanoparticles (Ag-NPs) were prepared by the biological reduction method. Green tea extract was taken as a reducing and stabilizing agent and silver nitrate as the metal precursor for nanoparticle synthesis. The formation of the silver nanoparticles was monitored visually and using UV-Visible absorption spectroscopy. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, FTIR, Zeta sizer, Zeta potential, and antimicrobial studies. Silver nanoparticles were also subjected to investigate nanocatalytic activity with standard pancreatic alpha-amylase and bacterial amylase enzyme by the DNS assay method. UV-Vis spectroscopy revealed the formation of silver nanoparticles by exhibiting the typical surface plasmon absorption maxima at 430 nm. Four major functional groups of bio-molecules such as phenol, carboxylic acid, protein, and alkyl group were recorded in FTIR spectra. The size of the nanoparticles ranges between 5nm and 150nm. The average size and size distribution of silver nanoparticles is 59.66nm. The zeta potential of the silver nanoparticle is negatively charged and rendered as a sharp peak at -31.7mV. Antimicrobial activity of silver nanoparticles exhibited the highest inhibition against Gram-negative bacteria than Gram-positive bacteria and yeast pathogens. Starch hydrolysis of Ag-NPs was studied with pancreatic alpha-amylase (tailor made), crude and purified bacterial amylase enzyme. The formation of reducing sugar was increased about 40-fold for a purified enzyme, 11-fold for the pancreatic enzyme, and 6-fold for crude bacterial enzyme incorporated with Ag-NPs over control. The present studies recommended that Ag-NPs have a significant role in the degradation of starch into reducing sugars by acting as a nanocatalyst.

scholarly journals Nonlinear optical absorption of non-spherical silver nanoparticles and organic dyes mixtures

2018 ◽  
Vol 190 ◽  
pp. 04016
Author(s):  
Andrey I. Zvyagin ◽  
Aleksey S. Perepelitsa ◽  
Mariya S. Lavlinskaya ◽  
Oleg V. Ovchinnikov ◽  
Mikhail S. Smirnov ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Optical Absorption ◽  
Nonlinear Optical ◽  
Optical Response ◽  
Nonlinear Optical Response ◽  
Saturable Absorption ◽  
Reverse Saturable Absorption ◽  
Photochemical Degradation ◽  
Ag Nps ◽  
Nonlinear Optical Absorption

We study the features of the nonlinear optical response of silver nanoparticles (Ag NPs) of spherical and triangular shapes synthesized using a citrate-borohydride approach and their mixtures with methylene blue (MB+). The Z-scans at the wavelengths of 532 nm using 10 ns pulses were used to analyze the nonlinear optical absorption of MB+ solutions, Ag NPs of different morphology, particularly, the concurrence of saturable and reverse saturable absorption in the solution of triangular Ag NP and MB+. We show the significant contribution to the increasing in the normalized transmittance accomplished by photochemical degradation of the non-spherical Ag NPs (extinction maximum of 600 nm) and transformation into the spherical ones (extinction maximum of 400 nm). The nonlinear light scattering is also analyzed, which showed the contribution to the variation of the sample transmission when it approaches the focal plane. It is shown that the nonlinear optical response is not additive in the mixture of Ag NPs and MB+. The increasing of the nonlinear absorption is probably due to both a change in the population of the triplet states of the dye and the efficiency of photochemical degradation of NPs in the presence of MB+.

scholarly journals Interaction of Pulses of Different Duration with Chemically Prepared Silver Nanoparticles: Analysis of Optical Nonlinearities

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ke Zhang ◽  
Rashid A. Ganeev ◽  
Konda Srinivasa Rao ◽  
Sandeep Kumar Maurya ◽  
Ganjaboy S. Boltaev ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Nonlinear Absorption ◽  
Nonlinear Optical ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Nonlinear Refraction ◽  
Optical Nonlinearities ◽  
Chemical Reduction Method ◽  
Ag Nps ◽  
Picosecond Pulses

The nonlinear optical properties of the aqueous solutions of silver nanoparticles (Ag NPs) prepared by chemical reduction method are analyzed using femtosecond and picosecond pulses at different wavelengths. In the case of 800 and 400 nm, the growths of nonlinear absorption and nonlinear refraction with the increase of Ag NP concentration, as well as a change at the signs of nonlinear optical processes, are determined. The nonlinear absorption coefficient and nonlinear refractive index of Ag NP solutions measured using picosecond pulses were a few orders of magnitude larger than those in the case of femtosecond probe pulses. We also demonstrate the optical limiting properties of Ag NPs using 800 nm, 60 fs pulses.

scholarly journals Synthesis and biological characterization of silver nanoparticles derived from the cyanobacterium Oscillatoria limnetica

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ragaa A. Hamouda ◽  
Mervat H. Hussein ◽  
Rasha A. Abo-elmagd ◽  
Salwa S. Bawazir
Keyword(s):  
Silver Nanoparticles ◽  
Cell Line ◽  
Fourier Transforms ◽  
Human Colon ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Ag Nps ◽  
Human Colon Cancer ◽  
Visible Absorption ◽  
Ft Ir

Abstract Using aqueous cyanobacterial extracts in the synthesis of silver nanoparticle is looked as green, ecofriendly, low priced biotechnology that gives advancement over both chemical and physical methods. In the current study, an aqueous extract of Oscillatoria limnetica fresh biomass was used for the green synthesis of Ag-NPs, since O. limnetica extract plays a dual part in both reducing and stabilizing Oscillatoria-silver nanoparticles (O-AgNPs). The UV-Visible absorption spectrum, Fourier transforms infrared (FT-IR), transmission electron microscopy (TEM) and scanning electron microscope (SEM) were achieved for confirming and characterizing the biosynthesized O-AgNPs. TEM images detected the quasi-spherical Ag-NPs shape with diverse size ranged within 3.30–17.97 nm. FT-IR analysis demonstrated the presence of free amino groups in addition to sulfur containing amino acid derivatives acting as stabilizing agents as well as the presence of either sulfur or phosphorus functional groups which possibly attaches silver. In this study, synthesized Ag-NPs exhibited strong antibacterial activity against multidrug-resistant bacteria (Escherichia coli and Bacillus cereus) as well as cytotoxic effects against both human breast (MCF-7) cell line giving IC50 (6.147 µg/ml) and human colon cancer (HCT-116) cell line giving IC50 (5.369 µg/ml). Hemolytic activity of Ag-NPs was investigated and confirmed as being non- toxic to human RBCs in low concentrations.

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