scholarly journals Biological Activity and Nanostructuration of Fe3O4-Ag/High Density Polyethylene Nanocomposites

2019 ◽  
Vol 3 (2) ◽  
pp. 34 ◽  
Author(s):  
Phuong Nguyen-Tri ◽  
Van Nguyen ◽  
Tuan Nguyen

We report here the synthesis of uniform nanospheres-like silver nanoparticles (Ag NPs, 5–10 nm) and the dumbbell-like Fe3O4-Ag hybrid nanoparticles (FeAg NPs, 8–16 nm) by the use of a seeding growth method in the presence of oleic acid (OA)/oleylamine (OLA) as surfactants. The antibacterial activity of pure nanoparticles and nanocomposites by monitoring the bacterial lag–log growth has been investigated. The electron transfer from Ag NPs to Fe3O4 NPs which enhances the biological of silver nanoparticles has been proven by nanoscale Raman spectroscopy. The lamellae structure in the spherulite of FeAg NPs/High Density Polyethylene (HDPE) nanocomposites seems to play the key role in the antibacterial activity of nanocomposites, which has been proven by nanoscale AFM-IR. An atomic force microscopy coupled with nanoscale infrared microscopy (AFM-IR) is used to highlight the distribution of nanoparticles on the surface of nanocomposite at the nanoscale. The presence of FeAg NPs in PE nanocomposites has a better antibacterial activity than that reinforced by Ag NPs due to the faster Ag+ release rate from the Fe3O4-Ag hybrid nanoparticles and the ionization of Ag NPs in hybrid nanostructure.

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ram Prasad ◽  
Vyshnava Satyanarayana Swamy

The unique property of the silver nanoparticles having the antimicrobial activity drags the major attention towards the present nanotechnology. The environmentally nontoxic, ecofriendly, and cost-effective method that has been developed for the synthesis of silver nanoparticles using plant extracts creates the major research interest in the field of nanobiotechnology. The synthesized silver nanoparticles have been characterized by the UV-visible spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM). Further, the antibacterial activity of silver nanoparticles was evaluated by well diffusion method, and it was found that the biogenic silver nanoparticles have antibacterial activity against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213), Pseudomonas aeruginosa (ATCC 27853), Azotobacter chroococcum WR 9, and Bacillus licheniformis (MTCC 9555).


2020 ◽  
pp. 1289-1297
Author(s):  
Ghada Mohammed Saleh

Soil bacteria play an interesting role in the reduction of Ag+ ions and the formation of silver nanoparticles (AgNPs), which may be a good source for nanoparticles and play a major role in nanotechnology applications. The concept of this project was to study the effects of these environmentally produced nanoparticles on the growth of some pathogenic bacteria. The environmental bacteria were isolated from soil, purified on broth cultures, and centrifuged, while the supernatant was extracted to detect its ability to convert silver nitrate to nanoparticles. The AgNPs was detected by Atomic Force Microscopy (AFM), while Granularity Cumulating Distribution (GCD) was employed to estimate the AgNPs sizes. The results showed the synthesis of AgNPs with sizes of 63.50nm and 45.81nm from the extracts of environmental Pseudomonas sp. and Enterobacter, respectively. The synthesized AgNPs from the extracts of all environmental bacteria showed antibacterial activity against some pathogenic bacteria (Gram positive and Negative) with variable inhibition zones. In conclusion, environmental bacteria can be a cheap source of nanoparticles.


2020 ◽  
Vol 7 (10) ◽  
pp. 201097
Author(s):  
Sana Rahim ◽  
Samina Perveen ◽  
Shakil Ahmed ◽  
Muhammad Raza Shah ◽  
Muhammad Imran Malik

The antibacterial activity of silver nanoparticles (AgNPs) stabilized with a four-armed star-shaped poly(ε-caprolactone)-block-poly(ethylene oxide) copolymer [St-P(CL-b-EO)] and its application as a drug delivery vehicle for cephalexin (Cp) was evaluated against pathogenic Staphylococcus aureus . The prepared AgNPs were characterized by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, zeta sizer and atomic force microscopy (AFM). The antibacterial efficiency of Cp is enhanced several-fold by its delivery through complexation with St-P(CL-b-EO)-AgNPs, monitored by microplate assay and biofilm destruction studies. Finally, the visual destruction of bacterial cells and its biofilms by employing Cp and its conjugates at their minimum inhibitory concentration (MIC 50 ) and minimum biofilm inhibitory concentration (MBIC 50 ), respectively, is observed by topographic imaging by AFM. Enhanced antibacterial activity of St-P(CL-b-EO)-AgNPs loaded Cp is attributed to penetrative nature of the drug cargo St-P(CL-b-EO)-AgNPs towards the bacterial cell wall.


2020 ◽  
pp. 1579-1588
Author(s):  
Ghada Mohammed Saleh ◽  
Shaymaa Suhail Najim

     Nanoparticles produced by plants are preferred in the medical field for its safe and unpolluted product; it is also accepted as an ecofriendly, non-expensive, and non-toxic nanomaterial. In this study, silver nitrate was successfully used to produce silver nanoparticles (AgNPs) by the use extractsof 4 different latex-producing plants which belong to 2 families (Moraceae and Euphorbiaceae). The synthesis was proved by Atomic Force Microscopy (AFM).The sizes of the AgNP grains were estimated by Granularity Cumulating Distribution (GCD). The results revealed the production of AgNPs in different sizes of 103 and 82 nm using the Moraceae family and 77 and74nm using the Euphorbiaceae family.Antibacterial activity was also detected against both Gram positive and Gram negative pathogenic bacteria using the well diffusion assay. In conclusion, this source of nanoparticles can be a very useful industrial project in a goal to find new safe and economic alternatives to antibiotics.


2021 ◽  
Vol 3 (1) ◽  
pp. 76-81
Author(s):  
Siti Husnaa Mohd Taib ◽  
Kamyar Shameli ◽  
Roshafima Rasit Ali ◽  
Zahra Izadiyan ◽  
Zatil Izzah Ahmad Tarmizi

The present paper reports the synthesis of silver nanoparticles (Ag-NPs) by a green method using Hibiscus sabdariffa (H. sabdariffa) leaves extract as reductant and stabilizer. The synthesized Ag-NPs were characterized by ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR). UV-vis spectrum of synthesized Ag-NPs showed a peak at 378 nm. TEM analysis revealed that the particles were spherical and irregular in shape and has average size around 56.52 nm. This structure and size of particles were confirmed by AFM analysis. The UV-vis and FTIR spectrum provides evidence of the presence of caffeic acid component as a representative biomolecule in stabilising the nanoparticles based on previous studies. Hence, this study advocates that H. sabdariffa have potential for synthesizing nanoparticles.


e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Liana Cătălina Ciobanu ◽  
Constantin Ciobanu

AbstractThe aim of this study was to investigate the effects of silver nanoparticles (Ag-NPs) concentration on surface of polyurethane microporous films. The Ag-NPs have a diameter between 1.74-10 nm and were synthesized in the polymer matrix. The effects of Ag-NPs at the surface of polyurethane (PU) microporous films were investigated by means of attenuated total reflection Fourier infrared (ATR-FTIR) spectroscopy, atomic force microscopy (AFM) and contact angle measurements. The mechanical behavior of PU films vs Ag-NPs concentration was also studied. The Ag-NPs induce changes in the PU surface structure, wettability properties, topography and mechanical properties. These phenomena may be due to interactions between Ag-NPs and urethane groups which form new structure urethane-silver-urethane with a specific morphology and the nanostructuring of the surface by means of metallic nanoparticles.


2021 ◽  
Vol 32 (3) ◽  
pp. 67
Author(s):  
Noor Fakher Khdr ◽  
Baida M. Ahmed ◽  
Bassam G. Rasheed

Various methods could be employed to synthesize nanomaterials. In this work laser induced forward technology was used to synthesize silver nanoparticles. Silver nanomaterials were tested using different measuring instruments such as UV–vis diffuse (DRS), Atomic Force Microscopy (AFM), and optical Microscope to characterize features such as the optical and morphological properties of these nanoparticles. AFM results show that when the laser energy of the pulsed Nd: YAG laser increases, the diameter and roughness of produced AgNPs will be decreased for the same number of pulses and the air cavity between donner and acceptor. Also, results show that when laser energy is (300,400) mJ, the AgNPs diameters are (95.76,88.44) nm and the roughness are (7,6) nm respectively. While, results show that as laser pulses increase, structure to be rougher for different laser pulses and constant laser energy at 300 mJ the same behavior will be found when the laser energy becomes 400mJ.Finally, results show that the reflectance peaks of Ag NPs increase by decreasing the number of pulses to a maximum value of 467 at 2 pulses.


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