A Green Approach for the Synthesis of Silver Nanoparticles Using Ultrasonic Radiation's Times in Sodium Alginate Media: Characterization and Antibacterial Evaluation (original) (raw)
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Investigation of antibacterial properties silver nanoparticles prepared via green method
Chemistry Central Journal, 2012
This study aims to investigate the influence of different stirring times on antibacterial activity of silver nanoparticles in polyethylene glycol (PEG) suspension. The silver nanoparticles (Ag-NPs) were prepared by green synthesis method using green agents, polyethylene glycol (PEG) under moderate temperature at different stirring times. Silver nitrate (AgNO 3 ) was taken as the metal precursor while PEG was used as the solid support and polymeric stabilizer. The antibacterial activity of different sizes of nanosilver was investigated against Gram-positive [Staphylococcus aureus] and Gram-negative bacteria [Salmonella typhimurium SL1344] by the disk diffusion method using Müeller-Hinton Agar.
Antibacterial effect of silver nanoparticles on Staphylococcus aureus
Research in Microbiology, 2011
The purpose of this study was to investigate the antibacterial effect of silver nanoparticles in chitosan-poly(ethylene glycol) suspension. The silver nanoparticles (AgNPs) were prepared by use of an environmentally benign method from chitosan (Cts) and poly(ethylene glycol) (PEG) at moderate temperature and with stirring for different times. Silver nitrate (AgNO 3 ) was used as the metal precursor and Cts and PEG were used as solid support and polymeric stabilizer, respectively. The antibacterial activity of silver-chitosan-poly(ethylene glycol) nanocomposites (Ag-Cts-PEG NCs) against Staphylococcus aureus, Micrococcus luteum, Pseudomonas aeruginosa, and Escherichia coli was tested by use of the Mueller-Hinton agar disk-diffusion method. Formation of AgNPs was determined by UV-visible spectroscopy; surface plasmon absorption maxima were observed at 415-430 nm in the UV-visible spectrum. The peaks in the XRD pattern confirmed that the AgNPs had a face-centered cubic structure; peaks of contaminated crystalline phases were not observed. Transmission electron microscopy (TEM) revealed that the AgNPs synthesized were spherical. The optimum stirring time for synthesis of the smallest particle size (mean diameter 5.50 nm) was 12 h. The AgNPs in Cts-PEG were effective against all the bacteria tested. Higher antibacterial activity was observed for AgNPs with smaller size. These results suggest that AgNPs can be used as an effective inhibitor of bacteria and can be used in medical applications. These results also suggest that AgNPs were successfully synthesized in Cts-PEG suspension at moderate temperature with different stirring times.
Green synthesis of silver nanoparticles and their antibacterial activities
Original article, 2022
Nanotechnology offers a solution to bacterial antibiotic resistance, which poses a serious threat to global health. Green synthesis of metallic nanoparticles is gaining increasing attention due to its environmental benefits. This study aimed to biosynthesize silver nanoparticles (AgNPs) by microwave irradiation through silver nitrate reduction using starch and microalgae biomass; characterize them using UV-visible spectroscopy, scanning electron microscopy-energy-dispersive X-ray microanalysis, and X-ray diffraction; and evaluate their antibacterial activity against Escherichia coli, Bacillus clausii, and Staphylococcus aureus using disk diffusion and broth dilution methods. Synthesized AgNPs showed a single peak related to surface plasmon resonance at 430 nm. Size range of spherical AgNPs was 40-150 or 90-400 nm for starch-or biomass-mediated NPs, respectively. Biomassmediated AgNPs exhibited antibacterial activity with the inhibition zones of 8, 12, and 10.5 mm against E. coli, B. clausii, and S. aureus, respectively; those starch-mediated showed inhibition of 7, 13, and 12 mm, respectively. AgNPs' minimum inhibitory concentrations were 6.25 μg•mL −1 toward both E. coli and S. aureus and 12.5 μg•mL −1 against B. clausii when using starch in biosynthesis, whereas they were 19.6 μg•mL −1 against both E. coli and S. aureus and 9.81 μg•mL −1 toward B. clausii when using biomass. Synthesized AgNPs have promising antibacterial potential.
In Vitro Antibacterial Activity of Biological-Derived Silver Nanoparticles: Preliminary Data
Veterinary Sciences, 2020
Silver nanoparticles (AgNPs) are promising alternatives to antibiotics. The aims of this study were to produce AgNPs using two biological methods and determine their antibacterial activity against Pseudomonas aeruginosa and Staphylococcus pseudintermedius. AgNPs were biosynthesized from an infusion of Curcuma longa (turmeric) and the culture supernatant of E. coli. Characterization was achieved by ultraviolet-visible spectroscopy and by Transmission Electron Microscopy (TEM). The antibacterial properties of NPs from C. longa (ClAgNPs) and E. coli (EcAgNPs), alone and in combination with carbenicillin and ampicillin, were investigated through the Kirby-Bauer disk diffusion assay and the minimum inhibitory concentration (MIC). Dimensions of NPs ranged from 11.107 ± 2.705 nm (ClAgNPs) to 27.282 ± 2.68 nm (EcAgNPs). Kirby-Bauer and MIC assays showed great antibacterial abilities for both NPs alone and in combination with antibiotics. EcAgNPs alone showed the most powerful antibacterial activities, resulting in MIC values ranging from 0.438 ± 0.18 µM (P. aeruginosa) to 3.75 ± 3.65 µM (S. pseudintermedius) compared to those of ClAgNPs: 71.8 ± 0 µM (P. aeruginosa) and 143.7 ± 0 µM (S. pseudintermedius). The antibiofilm abilities were strain-dependent, but no statistical differences were found between the two NPs. These results suggest the antibacterial potential of AgNPs for the treatment of infectious diseases.
Silver nanoparticles: green synthesis and their antimicrobial activities
Advances in colloid and interface science, 2009
This review presents an overview of silver nanoparticles (Ag NPs) preparation by green synthesis approaches that have advantages over conventional methods involving chemical agents associated with environmental toxicity. Green synthetic methods include mixed-valence polyoxometallates, polysaccharide, Tollens, irradiation, and biological. The mixed-valence polyoxometallates method was carried out in water, an environmentally-friendly solvent. Solutions of AgNO 3 containing glucose and starch in water gave starchprotected Ag NPs, which could be integrated into medical applications. Tollens process involves the reduction of Ag(NH 3 ) 2 + by saccharides forming Ag NP films with particle sizes from 50-200 nm, Ag hydrosols with particles in the order of 20-50 nm, and Ag colloid particles of different shapes. The reduction of Ag(NH 3 ) 2 + by HTAB (n-hexadecyltrimethylammonium bromide) gave Ag NPs of different morphologies: cubes, triangles, wires, and aligned wires. Ag NPs synthesis by irradiation of Ag + ions does not involve a reducing agent and is an appealing procedure. Eco-friendly bio-organisms in plant extracts contain proteins, which act as both reducing and capping agents forming stable and shape-controlled Ag NPs. The synthetic procedures of polymer-Ag and TiO 2 -Ag NPs are also given. Both Ag NPs and Ag NPs modified by surfactants or polymers showed high antimicrobial activity against Gram-positive and Gram-negative bacteria. The mechanism of the Ag NP bactericidal activity is discussed in terms of Ag NP interaction with the cell membranes of bacteria. Silver-containing filters are shown to have antibacterial properties in water and air purification. Finally, human and environmental implications of Ag NPs to the ecology of aquatic environment are briefly discussed.
Bacterial-mediated synthesis of silver nanoparticles and their significant effect against pathogens
Environmental Science and Pollution Research, 2020
Silver nanoparticles are potent antimicrobials and could be used as a promising alternative of conventional antibiotics. The aim of this study was to isolate bacteria from soil that have ability to produce AgNPs by secondary metabolite activity and their elucidation against human pathogens. These strains Escherichia coli, Exiguobacterium aurantiacumm, and Brevundimonas diminuta with NCBI accession number MF754138, MF754139, and MF754140 respectively were grown for secondary metabolite production. The nanoparticles were confirmed and characterized by UV-Vis spectroscopy and transmission electron microscopy. The optimization study was also carried out to obtain the maximum production of silver nanoparticles. Three parameters, temperature, pH, and AgNO3 concentration, were used to optimize the production of silver nanoparticles. Antimicrobial potential of these nanoparticles was addressed on the Muller-Hinton Agar, and their zones of inhibitions were measured. TEM analysis revealed the size and shape of the silver nanoparticles. All types of AgNPs were spherical in shape; their size range is from 5 to 50 nm. The findings of optimization study showed the maximum production of silver nanoparticles at the pH 9, temperature 37°C, and 1 mM AgNO3 concentration. All the strains exhibited the great potential as antimicrobial agents against MRSA and several other MDR bacteria with minimum 10 mm to maximum 28 mm zone of inhibition. It was concluded that the present study is an eco-friendly approach for the synthesis of AgNPs that will be beneficial to control the nosocomial infections triggered by MRSA and other human pathogens.
Green Synthesis of Ag Nanoparticles and Their Performance towards Antimicrobial Properties
Sains Malaysiana
Green synthesis is a forthcoming trend in the nanotechnology field where classical methods of synthesis are now replaced by inexpensive and eco-friendly methods. In this study, a green method has been developed for the synthesis of silver nanoparticles (AgNPs) where AgNPs were synthesised using water-based facile hydrothermal method. Silver nitrate (AgNO 3) and polyvinylpyrrolidone (PVP) were used as precursor and reducing agents to produce AgNPs. The molar ratio effect of the precursor and stabiliser, its reaction temperature and reaction time were investigated. X-ray Powder Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and UV-Vis Spectrometry were used to characterise the AgNPs. The as-synthesized AgNPs with different molar ratios of the precursor to stabiliser were tested for antibacterial activities using Gram-positive bacteria (Bacillus subtilis) and Gram-negative bacteria (Escherichia coli). All the AgNPs samples exhibited antibacterial activities that were stronger against Gram-negative bacteria, as compared with Gram-positive bacteria. The diameter of the zone of inhibition (ZOI) increased with the increase of the AgNO 3 : PVP molar ratios. The results obtained proved that uniform AgNPs synthesized via green techniques have a high potential of influencing applications involving antimicrobial properties.
Silver is easily available and is known to have microbicidal effect; moreover, it does not impose any adverse effects on the human body. The microbicidal effect is mainly due to silver ions, which have a wide antibacterial spectrum. Furthermore, the development of multidrug-resistant bacteria, as in the case of antibiotics, is less likely. Silver ions bind to halide ions, such as chloride, and precipitate; therefore, when used directly, their microbicidal activity is shortened. To overcome this issue, silver nanoparticles (Ag NPs) have been recently synthesized and frequently used as microbicidal agents that release silver ions from particle surface. Depending on the specific surface area of the nanoparticles, silver ions are released with high efficiency. In addition to their bactericidal activity, small Ag NPs (<10 nm in diameter) affect viruses although the microbicidal effect of silver mass is weak. Because of their characteristics, Ag NPs are useful countermeasures against infectious diseases, which constitute a major issue in the medical field. Thus, medical tools coated with Ag NPs are being developed. This review outlines the synthesis and utilization of Ag NPs in the medical field, focusing on environment-friendly synthesis and the suppression of infections in healthcare workers (HCWs).
2017
The synthesis of silver nanoparticles (Ag-NPs) has been conducted on the biopolymer media which is sodium alginate (Na-Alg) via the green method. Different times of ultrasound irradiation was used to reduce Ag + to be Ag seed (Ag 0) and produce Ag-NPs. The Ag-NPs was analyzed in their surface plasmon resonance (SPR), morphology, biomolecule responsible, and stability via UV-Vis, TEM, FTIR and Zeta potential, respectively. The application as antibacterial properties was studied against bacteria. Furthermore, this Ag-NPs could be synthesized using the green method and used as antibacterial efficacy for medical vehicles, would dressing, and so on.