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

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.

2018 ◽  
Vol 772 ◽  
pp. 73-77
Author(s):  
Ruelson S. Solidum ◽  
Arnold C. Alguno ◽  
Rey Capangpangan

We report on the green synthesis of silver nanoparticles utilizing theP.purpureumleaf extract. Controlling the surface plasmon absorption of silver nanoparticles was achieved by regulating the amount of extract concentration and the molarity of silver nitrate solution. The surface plasmon absorption peak is found at around 430nm. The surface plasmon absorption peak have shifted to lower wavelength as the amount of extract is increased, while plasmon absorption peak shifts on a higher wavelength as the concentration of silver nitrate is increased before it stabilized at 430nm. This can be explained in terms of the available nucleation sites promoted by the plant extract as well as the available silver ions present in silver nitrate solution.


2021 ◽  
Vol 16 (2) ◽  
Author(s):  
Rashmi Rawat ◽  
M. C. Purohit ◽  
Mahender Singh ◽  
Ankit S. Bartwal

Nowadays, for green synthesis, different parts of plant extracts are being used for the synthesis of metallic nanoparticles. Green routes for the synthesis of metallic nanoparticles are most favorable method over conventional methods. In this study, we have synthesized Ag nanoparticles from Terminalia bellirica aqueous leaves extract with AgNO3 solution. Recently, silver nanoparticles are being used for their beneficial effects on human health. It has been reported that it helps in lowering in cholesterol, blood pressure, thirst, pile, skin diseases and treatment of diabetes. Ag nanoparticles were characterized by UV-Vis spectrophotometer, XRD, TEM and FTIR techniques. It was found that Ag+ ion reduced into Ag0 and showed absorption band at 447 nm. X-Ray Diffraction for structural determination confirms the crystalline Ag nanoparticles. TEM analysis confirms the average particle size is less than 30 nm with spherical shape. FTIR spectra confirms the presence of active biomolecules (alcohols, phenols, proteins and nitro compounds) of plant leaves extract which played a key role in formation of Ag nanoparticles.


Author(s):  
Joud Jalab ◽  
Adawia Kitaz ◽  
Wassim Abdelwahed ◽  
Rawaa Al- Kayali

Aims: The green synthesis of silver nanoparticles in an eco-friendly, economical and more effective approach using (Acacia cyanophylla, Phlomis syriaca and Scolymus hispanicus) plants extracts and describing their main chemical properties and study the effect of its chemical composition on producing silver nanoparticles. Methodology: In this study, aqueous and ethanolic extracts of the three plants were evaluated for antioxidant activity using 2,2-diphenyl-l-picrylhydrazyl (DPPH) assay, Total polyphenol and flavonoid contents were determined using spectrophotometric method, but  total saponins were determined by weight method, The synthesis of silver nanoparticles was performed by a reduction method using aqueous silver nitrate solution and aqueous extracts of the three plants. Then study its characterization in a number of ways, such as visual inspection, UV-Vis spectroscopy and dynamic light scattering. Results: The results showed that the total phenolic content ranged in extracts between (13.08 ±2.279 to 98.39 ±4.755 mg GAE/g DW). While the total flavonoid contents varied from (19.83 ±2.384 to 121.64 ±6.469 mg RE/g DW. Antioxidant activity was expressed as IC50 and the obtained results ranged from (IC50= 0.027 ±0.00038 to 0.878 ±0.045 mg/ml), the results indicated that the ethanolic Acacia cyanophylla extract from the six examined extracts showed the highest phenolic and flavonoid concentration and strong antioxidant activity. Also, the saponins content in the three plants ranged from (0.46 to 2.53)% and the highest amount of saponins reported in Acacia cyanophylla plant. The silver nanoparticles prepared using Acacia cyanophylla extract have reported visible yellowish brown color formation and the absorption peak at 460 nm indicates the biosynthesis of silver nanoparticles and they have average diameter (134.1) nm and the polydispersity index (PdI) was suitable (0.260). Conclusion: Acacia cyanophylla extract has been considered as the best reducing agent among the selected plant extracts for the preparation of stable colloidal silver nanoparticles, this is due to their high content of flavonoids, phenols and saponins.


2015 ◽  
Vol 4 (6) ◽  
Author(s):  
Kaushik Roy ◽  
Chandan K. Sarkar ◽  
Chandan K. Ghosh

AbstractIn this study, we for the first time reported green synthesis of silver nanoparticles from silver nitrate solution using leaf extract of


2019 ◽  
Vol 31 (9) ◽  
pp. 2037-2041
Author(s):  
M. Reddeppa ◽  
R. Chenna Krishna Reddy ◽  
P. R. Sougandhi ◽  
S.S. Harini ◽  
T. Shobha Rani

Plant mediated green synthesis of silver nanoparticles (AgNPs) was carried out with the plant extract of Vitex negundo Linn., a simple method without using harmful chemicals. Herein, a root bark extract is used as reducing and capping agent for synthesizing AgNPs from silver nitrate solution. The characterization of AgNPs were obtained by UV-visible spectrophotometer, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive spectroscopy. The results were confirmed the presence of silver nanoparticles with UV-visible absorption peak at around 433-443 nm and its crystalline nature by XRD analysis. The FTIR spectrum confirmed that the synthesized AgNPs are stabilized and protected by various functional groups of biomolecules in extract. The SEM morphology showed the triangular or spherical shape of AgNPs with the size in the range of 80-100 nm and EDS confirmed the presence of elemental silver in the sample. The catalytic activity of AgNPs was investigated in the synthesis of 5-substituted 1H-tetrazole. Furthermore, antibacterial profile showed that biopotent AgNPs exhibited moderate to good antibacterial activity.


2019 ◽  
Author(s):  
Roberto Vazquez-Munoz ◽  
M. Josefina Arellano-Jimenez ◽  
Jose L. Lopez-Ribot

Abstract Objective Silver nanoparticles (AgNPs) can be difficult or expensive to obtain or synthesize for laboratories in resource-limited facilities. The purpose of this work was to create a fast, facile, and cost-effective method for synthesizing AgNPs with potent antimicrobial properties, that can be readily implemented in non-specialized laboratories.Results Our developed method uses a rather simple and rapid chemical reduction process that involves the addition of a polyvinylpyrrolidone solution to a warmed silver nitrate solution under constant vigorous stirring, immediately followed by the addition of sodium borohydride with constant stirring for an additional 15 minutes. AgNPs had an aspect ratio close to 1, with an average size of 6.18 ± 5 nm. AgNPs displayed potent antimicrobial activity, with Minimal Inhibitory Concentration values of 3 µg mL-1 and 1.5 µg mL-1 for Staphylococcus aureus and Candida albicans respectively.Keywords : Silver nanoparticles, nanoantibiotics, synthesis method, AgNPs, metallic nanoparticles


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Hernane S. Barud ◽  
Thaís Regiani ◽  
Rodrigo F. C. Marques ◽  
Wilton R. Lustri ◽  
Younes Messaddeq ◽  
...  

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.


NANO ◽  
2021 ◽  
pp. 2150088
Author(s):  
Kalthoum Chourabi ◽  
Lobna Elleuch ◽  
Salma Kloula ◽  
Ahmed Landoulsi ◽  
Abdelwaheb Chatti

Silver nanoparticles have attracted much interest from scientists to develop nanosilver-based disinfectant products due to their unique properties of high antimicrobial activity. This study focused on biosynthesis, characterization, antimicrobial and antibiofilm effects of silver nanoparticles against vegetative and starved Shigella strains. The silver nanoparticles were synthesized using the yeast Yarrowia lipolytica and characterized by ultraviolet–visible spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The antimicrobial and antibiofilm activities of silver nanoparticles were tested against the growth of vegetative and starved Shigella strains. After the addition of silver nitrate solution to the supernatant of Y. lipolytica, we noticed the appearance of a brown-black coloration that suggested the formation of silver nanoparticles. The presence of silver nanoparticles was manifested by a maximum absorption in the ultraviolet–visible range, precisely at the wavelength 420[Formula: see text]nm. The crystalline nature and the stability of silver nanoparticles were confirmed, respectively, by XRD and FTIR analysis. The antibacterial activity of silver nanoparticles showed significant toxicity on Shigella strains indicating that the starved cells were more sensitive to treatment with silver nanoparticles than vegetative cells. Surprisingly, the biofilm formation had not been inhibited by silver nanoparticles for both vegetative and starved cells. In conclusion, a new class of nanosilver containing disinfectant nanoproducts will be promising for advanced environmental treatments including air disinfection, water disinfection, surface disinfection and personal hygiene that will help to prevent the further outbreak of diseases.


2018 ◽  
Vol 18 (3) ◽  
pp. 421 ◽  
Author(s):  
Dian Susanthy ◽  
Sri Juari Santosa ◽  
Eko Sri Kunarti

A study to examine the performance of p-aminobenzoic acid as both reducing agent for silver nitrate to silver nanoparticles (AgNPs) and stabilizing agent for the formed AgNPs has been done. The synthesis of AgNPs was performed by mixing silver nitrate solution as precursor with p-aminobenzoic acid solution and heating it in a boiling water bath. After the solution turned to yellow, the reaction stopped by cooling it in tap water. The formed AgNPs were analyzed by using UV-Vis spectrophotometry to evaluate their SPR absorption in wavelength range of 400–500 nm. The synthesis process was highly depend on the pH, reaction time, and mole ratios of the reactants. The synthesis only occur in pH 11 and at reaction time 30 min, the particle size of the formed AgNPs was 12 ± 7 nm. Longer reaction time increased the reducing performance of p-aminobenzoic acid in AgNPs synthesis but decreased its stabilizing performance. The increase of silver nitrate amount relative to p-aminobenzoic acid in the synthesis increased the reducing and stabilizing performance of p-aminobenzoic acid and the optimum mole ratio between AgNO3 and p-aminobenzoic acid was 5:100 (AgNO3 to p-aminobenzoic acid).


2020 ◽  
Vol 11 (1) ◽  
pp. 8577-8586

Nanoparticle synthesis by the biological method is economical and environmentally friendly. In the present study, the biosynthesis of silver nanoparticles is performed by using extracts of Melia Azedarach plant leaves. The synthesis is performed by adding to the silver nitrate solution to the leaf extract of Melia azedarach. The color change state the precipitation of nanoparticles of silver. The silver nanoparticles obtained were characterized by various techniques such as X-ray diffraction (XRD), Scanning electron microscope (SEM), transmission electron microscope (TEM), and Energy dispersive spectroscopy (EDX). The XRD analysis shows the particle size of 11 nm calculated by the Debye-Scherrer. The microstructure analysis shows silver particles of spherical and triangular. The corrosion rate was found to be 0.025 mpy. The green silver nanoparticle (AgNPs) synthesized have better antimicrobial potential against both bacteria’s (Bacillus subtilis and Pseudomonas aeruginosa).


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