Green Synthesis of Silver Nanoparticles by Haloarchaeon Halococcus salifodinae BK6

2014 ◽  
Vol 938 ◽  
pp. 236-241 ◽  
Author(s):  
Pallavee Srivastava ◽  
Judith Braganca ◽  
Sutapa Roy Ramanan ◽  
Meenal Kowshik

Nanobiotechnology is a multidisciplinary branch of nanotechnology which includes fabrication of nanosized materials using biological approaches. Highly structured metallic and metal sulfide nanoparticles have been reported to be synthesized by numerous bacteria, fungi, yeasts and viruses. However, biosynthesis of nanoparticles by Haloarchaea (salt-loving archaea) of the third domain of life, Archaea, is in its nascent stages. In this study, we report the intracellular synthesis of stable, mostly spherical silver nanoparticles (SNPs) by the haloarchaeal isolateHalococcus salifodinaeBK6. The isolate adapted to silver nitrate was found to exhibit growth kinetics similar to that of cells unexposed to silver nitrate. The nitrate reductase enzyme assay and the enzyme inhibitor studies showed the involvement of NADH dependent nitrate reductase in silver tolerance, reduction, and synthesis of SNPs. UV visible spectroscopy, XRD, TEM and EDAX were used for characterization of SNPs. The XRD exhibited characteristic Bragg peaks of face centered cubic silver with crystallite domain size of 26 nm and 12 nm for SNPs synthesized in NTYE and halophilic nitrate broth, respectively. TEM analysis exhibited an average particle size of 50.3 nm and 12 nm for SNPs synthesized in NTYE and halophilic nitrate broth (HNB), respectively. The as synthesized SNPs exhibited antimicrobial activity against both Gram positive and Gram negative organisms.

2020 ◽  
Vol 10 (6) ◽  
pp. 7257-7264

Metal nanoparticles are gaining importance nowadays in nanoscience. The nanoparticle had better physical and chemical properties compared with solid particles due to their large surface area. The silver nanoparticles are employed mostly in medical and electrical applications having outstanding conductivity and antimicrobial activity. In the present investigation, NaBH4 and ethanol were used as a reductant and stabilizer agent from silver nitrate salt as a precursor. The silver nanoparticles obtained were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) to determine their morphology and size. In XRD analysis, the average particle size was found to be 18.31 nm. The TEM analysis shows crystalline morphology with a face-centered cubic structure. The antibacterial activity was tested against two bacterial cultures, namely Bacillus subtilis and Pseudomonas aeruginosa. The inhibition zones of 19mm and 17mm were observed against Bacillus subtilis and Pseudomonas aeruginosa, respectively.


Author(s):  
Liem Le ◽  
The Nguyen ◽  
Dieu Nguyen

In this work, silver nanoparticles (AgNPs) were synthesized rapidly and eco-friendlily using the extract of Mulberry leaves and aqueous solution of silver nitrate without any toxic chemical [1,2]. The Mulberry leaves extract acts as both reducing agent and stabilizing agent. The UV-Vis spectrum shows peak at 430 nm. The TEM image of synthesized AgNPs sample shows spherical shaped particles whose size range from 15 to 20 nm. TEM image of nano silver solution sample synthesized by microwave assisted method shows nearly spherical particles with an average particle size of 10 nm. The absorption UV-vis spectrum of silver nanoparticles synthesized by microwave assisted method (AgNPsmw) shows a sharp absorption band around 415 nm. After two month storage of AgNPsmw, the absorption spectrum of AgNPsmw was taken again. The UV-Vis spectrum shows negligible peak changes of silver nanoparticles have occurred after two months of storage. The synthesized AgNPs material could be used as an antimicrobial, used in the field of textile and in wastewater treatment.


Author(s):  
SNEHA THAKUR ◽  
KRISHNA MOHAN G

Objective: The main objective of the research work is to evaluate the antityrosinase potential of onion DNA silver nanoparticles (AgNPs). Methods: The onions were procured from the local market and DNA was extracted from onions using detergent and methylated spirit. The isolated DNA was selected for synthesis of AgNPs which acts as capping and reducing agent. About 10 ml of the DNA extract was added to 90 ml of 0.1 N silver nitrate solution. After 24 h incubation, the solution turned dark brown, which indicates the formation of AgNPs. The synthesized DNA AgNPs were characterized by ultraviolet-visible, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) studies. Results: The results revealed that the particles were uniform in shape with face-centered cubic structure. The particles are 153±20.4 nm in size and were no signs of agglomeration measured by DLS studies. The FTIR spectroscopy revealed B form of DNA along with strong N-H stretching, C=N stretching, and also asymmetric vibrations of phosphate groups characteristic for DNA molecule. The XRD studies revealed the face-centered cubic structure. SEM studies revealed the spherical structure with average particle size of 150±0.1 nm for single DNA nanoparticles. The onion DNA AgNPs were further investigated for its antityrosinase activity against the standard kojic acid and were to have anticancer potential nearer to the standard. Conclusion: From the results, it is evident that the synthesized onion DNA AgNPs have antityrosinase potential and can be further investigated for in vivo anticancer potential in future.


2020 ◽  
Vol 21 (4) ◽  
pp. 177
Author(s):  
Siti Suhartati ◽  
Iwan Syahjoko Saputra ◽  
Dwinna Rahmi ◽  
Yoki Yulizar ◽  
Sudirman Sudirman

BIOREDUCTION AND CHARACTERIZATION OF SILVER NANOPARTICLES FROM OIL PALM EMPTY FRUIT BUNCH (OPEFB). The synthesis of silver nanoparticles was successfully carried out by extracting oil palm empty fruit bunch. The precursor used was silver nitrate (AgNO3) with a concentration of 9x10-4 M and 5 wt% of the oil palm empty fruit bunch extract. OPEFB acted as a capping agent in the synthesis of silver nanoparticles. The bioreduction method Ag+ to Ag0 produced a silver nanoparticle colloid in brown color. The results of the UV-Vis spectrophotometer showed the silver nanoparticles colloids spectrum at a wavelength of 420 nm with an absorbance value of 0.5. FTIR shows the reduction and shift of absorption peak in the hydroxyl functional group (-OH) at wavenumbers of 3323 cm-1 and the presence of absorption peaks at 560 cm-1. While, XRD pattern showed the specific crystallinity peaks of silver nanoparticles at 2θ: 33.24°; 39.98°; 61.23°; dan 79.13° respectively with the face-centered cubic crystal structure (FCC) and crystallite size of 15 nm. PSA analysis showed two specific peaks with an average size distribution silver nanoparticles of 43.5 nm and a PDI value of 0.4. Analysis of TEM shows the average particle size of 20 nm with a spherical particle shape.


2018 ◽  
Vol 18 (12) ◽  
pp. 8386-8391 ◽  
Author(s):  
Muhammad Riaz ◽  
Muhammad Altaf ◽  
Muhammad Qayyum Khan ◽  
Saima Manzoor ◽  
Muhammad Azhar Shekheli ◽  
...  

Green syntheses of nanoparticles using plant materials are of tremendous scope. Here we report advantageous green synthesis for silver nanoparticles (AgNPs) using aqueous-root extract of Jurinea dolomiaea and AgNO3. Color change of solution and UV-Vis absorption at 444 nm indicated the formation of AgNPs. XRD confirmed their face centered cubic structure (fcc) with average particle size of 24.58 nm. SEM analysis showed their spherical, cubic and triangular structures. FT-IR indicated the presence of functional groups of reducing and stabilizing phytochemicals. Methanol-root extract of J. dolomiaea revealed high flavonoid (445 mg RE/g) and phenolic contents (92 mg GAE/g). Methanol-extract showed high antioxidant potency (IC50 = 0.494 μg/mL), rationally due to its high phenolic and flavonoid contents. These AgNPs showed the highest and equal antimicrobial activities against Escherichia coli and Pseudomonas aeruginosa (Inhibition zone 11.0 mm) whereas, methanol-roots extract showed equal and intermediate activities (Inhibition zone 8.0 mm) against both pathogens but aqueous extract showed poor activities (Inhibition zone 6.0 mm) against these both pathogens. AgNPs are playing a major role in the field of nanotechnology and nanomedicine due to their antimicrobial and drug delivery efficacy as well as reasonable tolerance in human biology.


2020 ◽  
Vol 9 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Samaira Yasmin ◽  
Shazia Nouren ◽  
Haq Nawaz Bhatti ◽  
Dure Najaf Iqbal ◽  
Shan Iftikhar ◽  
...  

AbstractCurrently, the green route for synthesis of silver nanoparticles (Ag NPs) using plants leaf extract is an emerging research area in nanotechnology. The present study was explored for synthesis, characterization and catalytic application of Ag NPs using Diospyros lotus fresh leaf extracts. Factors affecting the synthesis were optimized and optimum conditions were pH of 8.6, silver nitrate (AgNO3) concentration of 1.5 mM and 10 mL leaf extract. Formation of Ag NPs was observed by change in color of reaction mixture from pale yellow to reddish brown. The synthesized Ag NPs were characterized using UV-Vis spectrophotometer, EDX, XRD and SEM analyses. UV-Vis spectrophotometer showed maximum absorbance peak in the range of 407 nm at different time intervals indicating formation of Ag NPs. SEM and XRD analysis confirmed face centered cubic structure and crystalline nature of biologically synthesized Ag NPs with average particle size of 27 nm. The purity of synthesized Ag NPs was revealed by EDX. Finally, photo catalytic activity (PCA) of Ag NPs was studied and 72.91% decolorization of industrial waste water was obtained at 54 h. Some important parameters like pH, turbidity, conductance; TSS, TDS, sulphide, sulphates, etc. were also monitored before and after treatment with Ag NPs.


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.


2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Mingru Zhou ◽  
Zhiqiang Wei ◽  
Hongxia Qiao ◽  
Lin Zhu ◽  
Hua Yang ◽  
...  

In the protecting inert gas, silver nanoparticles were successfully prepared by confined arc plasma method. The particle size, microstructure, and morphology of the particles by this process were characterized via X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). TheN2absorption-desorption isotherms of the samples were measured by using the static volumetric absorption analyzer, the pore structure of the sample was calculated by Barrett-Joyner-Halenda (BJH) academic model, and the specific surface area was calculated from Brunauer-Emmett-Teller (BET) adsorption equation. The experiment results indicate that the crystal structure of the samples is face-centered cubic (FCC) structure the same as the bulk materials, the particle size distribution ranging from 5 to 65 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results. The specific surface area is 23.81 m2/g, pore volumes are 0.09 cm3/g, and average pore diameter is 18.7 nm.


Technologies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 7 ◽  
Author(s):  
Le Ngoc Liem ◽  
Nguyen Phuoc The ◽  
Dieu Nguyen

In this work, silver nanoparticles (AgNPs) were synthesized quickly and in an eco-friendly manner using the extract of Mulberry leaves and aqueous solution of silver nitrate without any toxic chemicals (Yuet et al. Int. J. Nanomed. 2012, 7, 4263–4267; Krishnakuma and Adavallan. Adv. Nat. Sci. Nanosci. Nanotechnol. 2014, 5, 025018). The Mulberry leaves extract functions as both a stabilizing and reducing agent. The UV-Vis spectroscopy shows a peak maximum at 430 nm. The transmission electron microscopy (TEM) image illustrated of synthesized AgNPs were nearly spherical-shaped particles whose sizes range from 15 to 20 nm. The TEM image of Nano Silver solution sample synthesized by the microwave assisted method shows nearly spherical particles, with an average particle size estimated at 10 nm. The absorption UV-vis spectrum of silver nanoparticles synthesized by the microwave assisted method (AgNPsmw) shows a sharp absorption band around 415 nm. The UV-Vis spectrum of AgNPsmw after two months of storage shows negligible peak changes of silver nanoparticles.


2019 ◽  
Vol 967 ◽  
pp. 145-149
Author(s):  
Diana Eka Pratiwi ◽  
Sumiati Side ◽  
Nur Aifah Tun Nisa

In recent years, the development of efficient green chemistry methods for synthesis of metal nanoparticles has become a major focus of researchers. One of the most considered methods is production of metal nanoparticles using plants. In this study silver nanoparticles (AgNPs) were rapidly synthesized by reacting silver ions with Moringa oleiferaL. leaf extract. The reaction process was simple and convenient to handle, and was monitored using ultraviolet-visible (UV-Vis) spectrophotometer. The crystalline phase of the AgNPs was determined from X-Ray Diffraction (XRD) patterns. The UV-vis spectra gave surface plasmon resonance for synthesized AgNPs at 465-473 nm. The XRD analysis showed that AgNPs are crystalline in nature and have face centered-cubic geometry with average particle size of 32 nm.


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