scholarly journals Biological Synthesis of Silver Nanoparticles by Cell-Free Extract ofSpirulina platensis

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Gaurav Sharma ◽  
Nakuleshwar Dut Jasuja ◽  
Manoj Kumar ◽  
Mohammad Irfan Ali

The present study explores biological synthesis of silver nanoparticles (AgNPs) using the cell-free extract ofSpirulina platensis. Biosynthesised AgNPs were characterised by UV-Vis spectroscopy, SEM, TEM, and FTIR analysis and finally evaluated for antibacterial activity. Extracellular synthesis using aqueous extract ofS. platensisshowed the formation of well scattered, highly stable, spherical AgNPs with an average size of 30–50 nm. The size and morphology of the nanoparticles were confirmed by SEM and TEM analysis. FTIR and UV-Vis spectra showed that biomolecules, proteins and peptides, are mainly responsible for the formation and stabilisation of AgNPs. Furthermore, the synthesised nanoparticles exhibited high antibacterial activity against pathogenic Gram-negative, that is,Escherichia coli, MTCC-9721;Proteus vulgaris, MTCC-7299;Klebsiella pneumoniae, MTCC-9751, and Gram-positive, that is,Staphylococcus aureus, MTCC-9542;S. epidermidis, MTCC-2639;Bacillus cereus, MTCC-9017, bacteria. The AgNPs had shown maximum zone of inhibition (ZOI) that is31.3±1.11inP. vulgaris. Use of such a microalgal system provides a simple, cost-effective alternative template for the biosynthesis of nanomaterials of silver in a large scale that could be of great use in biomedical applications.

2018 ◽  
Vol 7 (3) ◽  
pp. 1570
Author(s):  
Nguyen Phung Anh ◽  
Truong Thi Ai Mi ◽  
Duong Huynh Thanh Linh ◽  
Nguyen Thi Thuy Van ◽  
Hoang Tien Cuong ◽  
...  

A rapid way of synthesizing silver nanoparticles (AgNPs) by treating Ag+ ions with a green Fortunella Japonica (F.J.) extract as a combined reducing and stabilizing agent was investigated. The reaction solutions were monitored using UV-Vis spectroscopy, the size and shape of crystals were determined by scanning electron microscopy and transmission electron microscopy, the crystalline phases of AgNPs were presented by X–ray diffraction, and the relation of nanoparticles with Fortunella Japonica extract was confirmed using fourier transform infrared spectroscopy. The results indicated that no formation of AgNPs had taken place in the dark during 24 hours at room temperature and 40 oC. Meanwhile, it was found that the rate of AgNPs formation increased rapidly under the sunlight. The effects of the synthesis factors on the AgNPs formation were investigated. The suitable conditions for the synthesis of AgNPs using F.J. extract were determined as follows: F.J. extract was mixed with AgNO3 1.75 mM solution with the volume ratio of 3.5 AgNO3 solution/1.5 F.J. Extract, stirred 300 rpm for 150 minutes at 40 oC under sunlight illumination. At these conditions, AgNPs showed high crystalline structure with the average size of 15.9 nm. The antibacterial activity of silver nanoparticles was determined by agar well diffusion method against E. coli and B. subtilis bacteria. The green synthesized AgNPs performed high antibacterial activity against both bacteria.  


2021 ◽  
Vol 09 ◽  
Author(s):  
Sarvat Zafar ◽  
Aiman Zafar ◽  
Fakhra Jabeen ◽  
Miad Ali Siddiq

: Nanotechnology studies the various phenomena of physio-chemical procedures and biological properties for the generation of nanosized particles, and their rising challenges in the various sectors, like medicine, engineering, agriculture, electronic, and environmental studies. The nanosized particles exhibit good anti-microbial, anti-inflammatory, cytotoxic, drug delivery, anti-parasitic, anti-coagulant and catalytic properties because of their unique dimensions with large surface area, chemical stability and higher binding density for the accumulation of various bio-constituents on their surfaces. Biological approaches for the synthesis of silver nanoparticles (AgNPs) have been reviewed because it is an easy and single-step protocol and a viable substitute for the synthetic chemical-based procedures. Physical and chemical approaches for the production of AgNPs are also mentioned herein. Biological synthesis has drawn attention because it is cost-effective, faster, non-pathogenic, environment-friendly, easy to scale-up for large-scale synthesis, and having no demand for usage of high pressure, energy, temperature, or noxious chemical ingredients, and safe for human therapeutic use. Therefore, the collaboration of nanomaterials with bio-green approaches could extend the utilization of biological and cytological properties compatible with AgNPs. In this perspective, there is an immediate need to develop ecofriendly and biocompatible techniques, which strengthen efficacy against microbes and minimize toxicity for human cells. The present study introduces the biological synthesis of silver nanoparticles, and their potential biomedical applications have also been reviewed.


2020 ◽  
Vol 7 (7) ◽  
pp. 200065 ◽  
Author(s):  
Siti Nur Aishah Mat Yusuf ◽  
Che Nurul Azieyan Che Mood ◽  
Nor Hazwani Ahmad ◽  
Doblin Sandai ◽  
Chee Keong Lee ◽  
...  

Background : Silver nanoparticles (AgNPs) are widely used in food industries, biomedical, dentistry, catalysis, diagnostic biological probes and sensors. The use of plant extract for AgNPs synthesis eliminates the process of maintaining cell culture and the process could be scaled up under a non-aseptic environment. The purpose of this study is to determine the classes of phytochemicals, to biosynthesize and characterize the AgNPs using Clinacanthus nutans leaf and stem extracts. In this study, AgNPs were synthesized from the aqueous extracts of C. nutans leaves and stems through a non-toxic, cost-effective and eco-friendly method. Results : The formation of AgNPs was confirmed by UV-Vis spectroscopy, and the size of AgNP-L (leaf) and AgNP-S (stem) were 114.7 and 129.9 nm, respectively. Transmission electron microscopy (TEM) analysis showed spherical nanoparticles with AgNP-L and AgNP-S ranging from 10 to 300 nm and 10 to 180 nm, with average of 101.18 and 75.38 nm, respectively. The zeta potentials of AgNP-L and AgNP-S were recorded at −42.8 and −43.9 mV. X-ray diffraction analysis matched the face-centred cubic structure of silver and was capped with bioactive compounds. Fourier transform infrared spectrophotometer analysis revealed the presence of few functional groups of phenolic and flavonoid compounds. These functional groups act as reducing agents in AgNPs synthesis. Conclusion : These results showed that the biogenically synthesized nanoparticles reduced silver ions to silver nanoparticles in aqueous condition and the AgNPs formed were stable and less toxic.


2015 ◽  
Vol 1109 ◽  
pp. 30-34 ◽  
Author(s):  
M.K. Nahar ◽  
Zarina Zakaria ◽  
U. Hashim ◽  
Md Fazlul Bari

Nanotechnology is a most promising area that is increasing day by day and play a vital role in environments, biotechnological and biomedical fields. In recent years, the development of effective green chemistry methods for synthesis of various metal nanoparticles has become a main focus of researchers. They have investigated to find out a sustainable technique for production of well-characterized nanoparticles. A variety of chemical and physical methods have been exploited in the synthesis of silver nanoparticles (AgNPs) and these procedures remain expensive, high energy consumption and involve the use of hazardous chemicals. Therefore, there is an essential need to develop environmentally benign and sustainable procedures for synthesis of metallic nanoparticles. Increasing awareness of green chemistry and biological processes has need to develop a rapid, simple, cost-effective and eco-friendly methods. One of the most considered methods is production of nanosilver using plants and plant-derived materials which is the best candidates and suitable for large-scale biosynthesis of silver nanoparticles. Eco-friendly bio-organisms in plant extracts contain proteins, which act as both capping and reducing agents forming of stable and shape-controlled AgNPs. This review describes the recent advancements in the green synthesis of silver nanoparticles by using plants.


Author(s):  
Sharmila C ◽  
Ranjith Kumar R ◽  
Chandar Shekar B

 Objective: Synthesis of silver nanoparticles (AgNPs) using a simple, cost-effective and environmentally friendly green route approach and to study the antibacterial activity of AgNPs against human pathogens.Methods: Green route approach is used to synthesize AgNPs using Psidium guajava leaf extract. Fourier transform infrared (FTIR) was used to identify the presence of the functional group. X-ray diffraction (XRD) was used to analyze the structure of prepared AgNPs. Energy dispersive X-ray was used to the characteristic to the composition of the prepared nanoparticles. Size and morphology of the prepared AgNPs were investigated using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis. Antibacterials efficiency of prepared AgNPs was tested against Escherichia coli and Staphylococcus aureus by well diffusion methods.Results: FTIR study shows the presence of different functional groups present in the leaves mediated AgNPs. The XRD studies yield diffraction peaks corresponding to face-centered cubic structure of Ag crystals. Spherical shaped AgNPs with a particle size of about ~55 nm were evidenced using FESEM and TEM analysis. Energy dispersive spectrum of the synthesized AgNPs confirms the presence of silver in the prepared nanoparticles. From UV-VIS analysis it is shown that the absorption band was red-shifted from 430 nm to 456 nm. The prepared AgNPs shows good antibacterial activity against E. coli and S. aureus.Conclusions: P. guajava leaf extract is a potential reducing agent to synthesize AgNPs. The green synthesis approach provides cost-effective and eco-friendly nanoparticles, which could be used in biomedical applications.


Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2383
Author(s):  
Majid Sharifi-Rad ◽  
Pawel Pohl ◽  
Francesco Epifano ◽  
José M. Álvarez-Suarez

Today, the green synthesis of metal nanoparticles is a promising strategy in material science and nanotechnology. In this research, silver nanoparticles (AgNPs) were synthesized through the high-efficient, cost-effective green and facile process, using the Astragalus tribuloides Delile. root extract as a bioreduction and capping agent at room temperature. UV–Vis spectroscopy was applied for the investigation of the reaction proceedings. To characterize the greenly synthesized AgNPs, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), and transmission electron microscopy (TEM) analyses were utilized. In addition, the total phenolics and flavonoids contents, antioxidant, antibacterial, and anti-inflammatory activities of the greenly synthesized AgNPs and the A. tribuloides root extract were evaluated. The results indicated that the AgNPs had spherical morphology and crystalline structure with the average size of 34.2 ± 8.0 nm. The total phenolics and flavonoids contents of the greenly synthesized AgNPs were lower than those for the A. tribuloides root extract. The resultant AgNPs exhibited the appropriate antioxidant activity (64%) as compared to that for the A. tribuloides root extract (47%). The antibacterial test approved the higher bactericidal activity of the resulting AgNPs on the Gram-positive and Gram-negative bacteria in comparison to the A. tribuloides root extract. Considering the anti-inflammatory activity, the greenly synthesized AgNPs showed a stranger effect than the A. tribuloides root extract (82% versus 69% at 500 μg/mL). Generally, the AgNPs that were fabricated by using the A. tribuloides root extract had appropriate antioxidant, antibacterial, and anti-inflammatory activities and, therefore, can be considered as a promising candidate for various biomedical applications.


2021 ◽  
Vol 22 (4) ◽  
pp. 1905
Author(s):  
Jimmy Gouyau ◽  
Raphaël E. Duval ◽  
Ariane Boudier ◽  
Emmanuel Lamouroux

Multidrug-resistant (MDR) bacteria constitute a global health issue. Over the past ten years, interest in nanoparticles, particularly metallic ones, has grown as potential antibacterial candidates. However, as there is no consensus about the procedure to characterize the metallic nanoparticles (MNPs; i.e., metallic aggregates) and evaluate their antibacterial activity, it is impossible to conclude about their real effectiveness as a new antibacterial agent. To give part of the answer to this question, 12 nm gold and silver nanoparticles have been prepared by a chemical approach. After their characterization by transmission electronic microscopy (TEM), Dynamic Light Scattering (DLS), and UltraViolet-visible (UV-vis) spectroscopy, their surface accessibility was tested through the catalytic reduction of the 4-nitrophenol, and their stability in bacterial culture medium was studied. Finally, the antibacterial activities of 12 nm gold and silver nanoparticles facing Staphylococcus aureus and Escherichia coli have been evaluated using the broth microdilution method. The results show that gold nanoparticles have a weak antibacterial activity (i.e., slight inhibition of bacterial growth) against the two bacteria tested. In contrast, silver nanoparticles have no activity on S. aureus but demonstrate a high antibacterial activity against Escherichia coli, with a minimum inhibitory concentration of 128 µmol/L. This high antibacterial activity is also maintained against two MDR-E. coli strains.


Author(s):  
S. Prathimaa ◽  
J. Anbumalarmathi ◽  
S. Aruna Sharmili

Plant mediated fabrication of nanoparticles and nanomaterials are gaining momentum as it is eco-friendly and cost-effective. In the present study, we synthesis of Silver nanoparticles using aqueous extract of  Quercus infectoria nuts and Daucus carota subsp sativum leaves. The surface plasma resonance at 417 and 450 nm for Q. infectoria and D. carota respectively confirmed the formation of AgNPs. Scanning Electron Microscopic (SEM) confirmed the spherical shape of the nanoparticles, which had an average size of 67.5 nm and 49.2 nm for Q. infectoria nanoparticles (QAgNPs)and D. carota nanoparticles (DAgNPs). The elemental composition by Energy-Dispersive X-ray analysis of the nanoparticle showed an atomic percentage of silver as 73.64 % and 75.93% for Q. infectoria and D. carota.FT- IR analysis of the plant extracts and synthesized silver nanoparticles showed the presence of various functional groups. The total antioxidant activity of QAgNPs was 81.18% and that of DAgNPs was 73.36%. The QAgNPs and DAgNPs exhibited antibacterial activity against B. subtilis, E. coli and S. aureus. The percentage of cell viability for QAgNPs and DAgNPs assessed using HeLa cells was 21.1% and 6% respectively.


Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 627 ◽  
Author(s):  
Bianca Moldovan ◽  
Vladislav Sincari ◽  
Maria Perde-Schrepler ◽  
Luminita David

The present study reports for the first time the efficacy of bioactive compounds from Ligustrum ovalifolium L. fruit extract as reducing and capping agents of silver nanoparticles (AgNPs), developing a green, zero energetic, cost effective and simple synthesis method of AgNPs. The obtained nanoparticles were characterized by UV-Vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR), confirming that nanoparticles were crystalline in nature, spherical in shape, with an average size of 7 nm. The FTIR spectroscopy analysis demonstrated that the AgNPs were capped and stabilized by bioactive molecules from the fruit extract. The cytotoxicity of the biosynthesized AgNPs was in vitro evaluated against ovarian carcinoma cells and there were found to be effective at low concentration levels.


2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Abdullah A. Alarfajj ◽  
Mohammedsaleh Almallahi ◽  
Murugan A. Munusamy ◽  
Mickymaray Suresh ◽  
Wael Alturaiki

Extended-spectrum beta-lactamases (ESBL) are enzymes produced by E. coli like some gram negative bacteria. The patients who are affected by ESBL producing bacteria facing a major problem and they may need different β- lactam antibiotics to treat the infection. But this extensive use of β- lactam antibiotics against ESPLs creating major public health threat.  As an alternative currently many eco- friendly, non-toxic, low cost nanoparticles are synthesizing by biogenic way used as an alternative for the β- lactam antibiotics. In the present study silver nanoparticles (AgNPs) were synthesized using Ayurveda Toothpowder. The synthesized AgNPs were characterized using ultraviolet (UV)-visible (vis) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscope (TEM) analysis and finally the antibacterial activity was performed against ESBL producing bacteria by well diffusion method. Antibacterial tests against ESPL producing E.coli cells using biogenic synthesized AgNPs showed significant antibacterial effect at low concentration of AgNPs. The results proved that the biogenic synthesised nanoparticles using Toothpowder extract would help to arrest ESBL producing bacteria a


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