scholarly journals Green Synthesis, Characterization, and Antibacterial Activity of Silver/Polystyrene Nanocomposite

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Manal A. Awad ◽  
W. K. Mekhamer ◽  
Nada M. Merghani ◽  
Awatif A. Hendi ◽  
Khalid M. O. Ortashi ◽  
...  

A novel, nontoxic, simple, cost-effective and ecofriendly technique was used to synthesize green silver nanoparticles (AgNPs). The AgNPs were synthesized using orange peel extract as a reducing agent for silver nitrate salt (AgNO3). The particle size distribution of AgNPs was determined by Dynamic Light Scattering (DLS). The average size of silver nanoparticles was 98.43 nm. The stable dispersion of silver nanoparticles was added slowly to polystyrene solution in toluene maintaining the temperature at 70°C. The AgNPs/polystyrene (PS) nanocomposite solution was cast in a petri dish. The silver nanoparticles encapsulated within polymer chains were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectroscopy (EDS) in addition to Transmission Electron Microscopy (TEM). The green AgNPs/PS nanocomposite film exhibited antimicrobial activity against Gram-negative bacteriaEscherichia coli, Klebsiella pneumoniae and Salmonella, and Gram-positive bacteriaStaphylococcus aureus. Thus, the key findings of the work include the use of a safe and simple AgNPs/PS nanocomposite which had a marked antibacterial activity which has a potential application in food packaging.

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.  


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3790
Author(s):  
Pratama Jujur Wibawa ◽  
Muhammad Nur ◽  
Mukhammad Asy’ari ◽  
Wijanarka Wijanarka ◽  
Heru Susanto ◽  
...  

This research aimed to enhance the antibacterial activity of silver nanoparticles (AgNPs) synthesized from silver nitrate (AgNO3) using aloe vera extract. It was performed by means of incorporating AgNPs on an activated carbon nanoparticle (ACNPs) under ultrasonic agitation (40 kHz, 2 × 50 watt) for 30 min in an aqueous colloidal medium. The successful AgNPs synthesis was clarified with both Ultraviolet-Visible (UV-Vis) and Fourier Transform Infrared (FTIR) spectrophotometers. The successful AgNPs–ACNPs incorporation and its particle size analysis was performed using Transmission Electron Microscope (TEM). The brown color suspension generation and UV-Vis’s spectra maximum wavelength at around 480 nm confirmed the existence of AgNPs. The particle sizes of the produced AgNPs were about 5 to 10 nm in the majority number, which collectively surrounded the aloe vera extract secondary metabolites formed core-shell like nanostructure of 8.20 ± 2.05 nm in average size, while ACNPs themselves were about 20.10 ± 1.52 nm in average size formed particles cluster, and 48.00 ± 8.37 nm in average size as stacking of other particles. The antibacterial activity of the synthesized AgNPs and AgNPs-immobilized ACNPs was 57.58% and 63.64%, respectively (for E. coli); 61.25%, and 93.49%, respectively (for S. aureus). In addition, when the AgNPs-immobilized ACNPs material was coated on the cotton and polyester fabrics, the antibacterial activity of the materials changed, becoming 19.23% (cotton; E. coli), 31.73% (polyester; E. coli), 13.36% (cotton; S. aureus), 21.15% (polyester; S. aureus).


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Moira Carmalita Dharsika Niluxsshun ◽  
Koneswaran Masilamani ◽  
Umaramani Mathiventhan

Wide application of nanoparticles motivates the need for synthesising them. Here, a nontoxic, eco-friendly, and cost-effective method has been established for the synthesis of silver nanoparticles using extracts of lemon peel (Citrus limon), green orange peel (Citrus sinensis), and orange peel (Citrus tangerina). The synthesised nanoparticles have been characterised using UV-visible absorptionspectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy (TEM). The UV-visible absorption spectrum of these synthesised silver nanoparticles shows an absorption peak at around 440 nm. TEM images show different shaped particles with various sizes. Furthermore, the antibacterial activity of silver nanoparticles was appraised by a well-diffusion method and it was observed that the green synthesised silver nanoparticles have an effective antibacterial activity against Escherichia coli and Staphylococcus aureus. The outcome of this study could be beneficial for nanotechnology-based biomedical applications.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Liling Jing ◽  
Mark G. Moloney ◽  
Hao Xu ◽  
Lian Liu ◽  
Wenqiang Sun ◽  
...  

Abstract Silver nanoparticles (Ag NPs) system capable of exhibiting different particle size at different temperature was developed, which depended on the extent of Diels–Alder (DA) reaction of bismaleimide with furan. Thus, Ag NPs were functionalized on the surface by a furyl-substituted carbene through an insertion reaction. Subsequent reversible DA crosslinking achieved a controlled aggregation with different particle size, which gives a series of different antibacterial activity. These Ag NPs were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Nanoparticle Size Analyzer. The aggregation of the Ag NPs could be reliably adjusted by varying the temperature of DA/reverse-DA reaction. The antibacterial activity was assessed using the inhibition zone method against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which decreased first and then increased in agreement with the size evolution of Ag NPs. This approach opens a new horizon for the carbene chemistry to modify silver nanoparticles with variable size and give controlled antibacterial activity.


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.


Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 260 ◽  
Author(s):  
Syed Ghazanfar Ali ◽  
Mohammad Azam Ansari ◽  
Mohammad A. Alzohairy ◽  
Mohammad N. Alomary ◽  
Mohammad Jalal ◽  
...  

Synthesis of nanoparticles using the plants has several advantages over other methods due to the environmentally friendly nature of plants. Besides being environmentally friendly, the synthesis of nanoparticles using plants or parts of the plants is also cost effective. The present study focuses on the biosynthesis of zinc oxide nanoparticles (ZnO NPs) using the seed extract of Butea monsoperma and their effect on to the quorum-mediated virulence factors of multidrug-resistant clinical isolates of Pseudomonas aeruginosa at sub minimum inhibitory concentration (MIC). The synthesized ZnO NPs were characterized by different techniques, such as Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and transmission electron microscopy (TEM). The average size of the nanoparticles was 25 nm as analyzed by TEM. ZnO NPs at sub MIC decreased the production of virulence factors such as pyocyanin, protease and hemolysin for P. aeruginosa (p ≤ 0.05). The interaction of NPs with the P. aeruginosa cells on increasing concentration of NPs at sub MIC levels showed greater accumulation of nanoparticles inside the cells as analyzed by TEM.


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.


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.


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.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Mogomotsi Kgatshe ◽  
Oluwole S. Aremu ◽  
Lebogang Katata-Seru ◽  
Ramokone Gopane

Development of cost-effective and eco-friendly methods of nanoparticle synthesis could play a crucial role in integrating nanotechnology and phytomedicine for biological applications. In this study, biogenic silver nanoparticles (AgNPs) were synthesized using the ethanolic extract of Pelargonium sidoides DC at 60°C. Formation of nanoparticles was monitored using UV-Visible spectroscopy at different time intervals. A maximum absorption at 456 nm was observed as the reaction time increased, resulting in a red shift of the surface plasmon band (SPB). Attenuated total reflectance Fourier transform infrared spectroscopy (FTIR) revealed the reducing and stabilizing activity of flavonoids, coumarins, tannins, and phenols. Size and morphology of the AgNPs were analysed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) which indicated the spherical nature of the nanoparticles with sizes ranging from 11 to 90 nm. Further characterization of the AgNPs was carried out using EDS, XRD, and Raman spectroscopy, respectively. Additionally, the AgNPs had a marginally higher antimicrobial activity when compared to the plant extract against Gram-positive Streptococcus pneumoniae (ATCC 27336) and Bacillus cereus (ATCC 10876) and Gram-negative Moraxella catarrhalis (ATCC 25240), Escherichia coli (ATCC 25922), and Pseudomonas aeruginosa (ATCC 27853).


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