scholarly journals Antibacterial Activity of Silver Nanoparticles Capped by p-Aminobenzoic Acid on Escherichia coli and Staphylococcus aureus

2019 ◽  
Vol 20 (1) ◽  
pp. 182
Author(s):  
Dian Susanthy ◽  
Sri Juari Santosa ◽  
Eko Sri Kunarti
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Silver Nitrate ◽  
Nitrate Concentration ◽  
Aminobenzoic Acid ◽  
Antibacterial Performance ◽  
Silver Nitrate Concentration

This paper describes the antibacterial performance of silver nanoparticles (AgNPs) which have been synthesized by using p-aminobenzoic acid as reducing and stabilizing agent simultaneously. The silver nitrate with various concentrations was reacted with pH 11-adjusted p-aminobenzoic acid with a concentration of 5 × 10–3 mol L–1 for 30 min in a boiling water bath. The synthesized AgNPs were characterized by UV-Vis spectrophotometry, Transmission Electron Microscope (TEM), and Particle Size Analyzer (PSA). The antibacterial performance of the synthesized AgNPs was evaluated by agar well diffusion method on Escherichia coli and Staphylococcus aureus. The higher silver nitrate concentration, the bigger the nanoparticle size, the wider particle size distribution, and the higher number of AgNPs formed. AgNPs synthesized from higher silver nitrate concentration had higher antibacterial activity. It is an indication that the antibacterial activity of AgNPs is mainly controlled by the silver ion concentration which influences the AgNPs particle size and existence of silver ion in the AgNPs colloidal solution

scholarly journals Influence of Physico-Chemical Parameters on the Fabrication of Silver Nanoparticles Using Petrea volubilis L. Stem Broth and Its Anti-Microbial Efficacy

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
N. I. Hulkoti ◽  
T. C. Taranath
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Silver Nitrate ◽  
Microbial Activity ◽  
Contact Time ◽  
Nitrate Concentration ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Vis Spectroscopy ◽  
Silver Nitrate Concentration

In this study we describe the phytofabrication of AgNps through a green route as a cost-effective, instantaneous and an eco-friendly approach using Petrea volubilis L. stem broth. The influence of physico-chemical parameters - contact time, stem broth quantity, pH, temperature, and silver nitrate concentration were studied and optimised to engineer, nanoparticles of diverse sizes. Nanoparticles were characterized by UV-Vis spectroscopy, FTIR, XRD, Zeta potential, EDS, and HRTEM. The characterization using HRTEM showed that, the nanoparticles were spherical and with increase in contact time, stem broth quantity, pH, and temperature, the NPs size minimised whereas escalation in silver nitrate concentration, increased their size. Capping molecules were negatively charged and the NPs were passably stable according to zeta potential readings and they were crystalline as per XRD data. According to FTIR analysis, the bio reduction was attributed to alcohol, ethers, carboxylic acids, and esters. The highest anti-bacterial activity was observed against S. aureus and S. typhi whose ZOI diameter was 13 mm at 100?l in both bacteria. The highest anti-fungal activity of silver nanoparticles was observed against A. flavus whose ZOI diameter was 9 mm at 100?l compared to P. chrysogenum which is 3 mm at 100?l. The stem broth did not show any anti-microbial activity for the microbes. Anti-microbial activity of AgNPs is due to its small size and high surface area. Our findings clearly discloses that sizes of silver nanoparticles can be varied by varying the physico-chemical parameters and the small sized nanoparticles so formed are promising antimicrobial agents and has a great potential in various medical applications.

scholarly journals Effect of Storage Period on Silver Nanoparticles Biosynthesized By Pseudomonas Aeroginosa

2019 ◽  
Vol 9 (04) ◽  
pp. 678-681
Author(s):  
Ashraf S Hassan ◽  
Khawlah J Khalaf ◽  
Hamzia A Ajah
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Candida Albicans ◽  
Storage Period ◽  
Before And After ◽  
Pathogenic Microbes

The present study demonstrates the effect of storage period on silver nanoparticles (AgNPs), which synthesized by Pseudomonas aeruginosa and their antibacterial activity. The result shows that the size of (AgNPs) which synthesis by Pseudomonas aeruginosa was 93.55nm after 4-72hour, and when storage about 2 years, we found that the size of AgNPs was stable and reduced to 69.0nm. Antibacterial activity against pathogenic microbes: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Serratia sp,Streptococcus sp , Klebsiella sp, Candida albicans was performed before and after storage and found that AgNPs have activity against this microbes.

scholarly journals Green Synthesis of Silver Nanoparticles Using Moringa Oleifera Leaf Extract, Tamarindus Indica Fruit Extract and Assessement of Antibacterial Activity Against Staphylococcus Aureus

2021 ◽  
Author(s):  
Shirisha A ◽  
ANUMOLU VIJAYA KUMAR ◽  
Laxman Chatlod R ◽  
Shashi Kumar M ◽  
Krishnaiah N ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Silver Nitrate ◽  
Leaf Extract ◽  
Moringa Oleifera ◽  
Diffusion Method ◽  
Tamarindus Indica ◽  
Fruit Extract

Abstract The present study mainly deals with the green synthesis, characterization and evaluation of antibacterial properties of silver nanoparticles (AgNPs) synthesized by using the leaf extract of Moringa oleifera and fruit extract of Tamarindus indica. In this study for synthesis of silver nanoparticles different ratios of 1mM silver nitrate and Moringa oleifera leaf extract i.e, 95:5, 90:10 and 85: 15 was taken in conical flask and kept for one 1 hr at 25 0 c on magnetic stirrer, out of which 90:10 ratio was selected for further study based on highest peak, good size and stability. Tamarindus indica fruit extract was added to silver nitrate solution till the colour of the solution changes from light brown to chocolate brownish colour. The synthesized silver nanoparticles were characterized by UV-Visible spectroscopy, Zeta potential, size distribution by intensity. The absorption spectrum of the silver nano solution prepared by using Moringa oleifera and Tamarindus indica fruit extract showed a surface plasmon absorption band with maximum of 420 nm and 430 nm respectively indicating the presence of silver nanoparticles. The zeta value of silver nanoparticles synthesized from Moringa oleifera and Tamarindus indica fruit extract was -12.5 mV and -15.5 mV, size of 110.2 nm and 130.2 nm respectively. The antibacterial efficacy of nanosilver was checked by agar well diffusion method, and the silver nanoparticles showed effective antibacterial activity against Staphylococcus aureus.

scholarly journals Hydrothermal Fabrication of Spindle-Shaped ZnO/Palygorskite Nanocomposites Using Nonionic Surfactant for Enhancement of Antibacterial Activity

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1453 ◽  
Author(s):  
Aiping Hui ◽  
Shuqing Dong ◽  
Yuru Kang ◽  
Yanmin Zhou ◽  
Aiqin Wang
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Low Cost ◽  
Ionic Surfactants ◽  
E Coli ◽  
Antibacterial Performance ◽  
Good Antibacterial Activity ◽  
Controllable Growth ◽  
And Staphylococcus Aureus

In order to improve the antibacterial performance of natural palygorskite, spindle-like ZnO/palygorskite (ZnO/PAL) nanocomposites with controllable growth of ZnO on the surface of PAL were prepared in the presence of non-ionic surfactants using an easy-to-operate hydrothermal method. The obtained ZnO/PAL nanocomposites have a novel and special spindle-shaped structure and good antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and are also low cost. The minimum inhibitory concentrations of ZnO/PAL nanocomposites toward E. coli and S. aureus reached 1.5 and 5 mg/mL, respectively.

Preparation and Antimicrobial Activity of Antibacterial Silver-Loaded Polyphosphazene Microspheres

2021 ◽  
Vol 21 (10) ◽  
pp. 5120-5130
Author(s):  
Hui Long ◽  
Wei-Cong Kuang ◽  
Shi-Liang Wang ◽  
Jing-Xian Zhang ◽  
Lang-Huan Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Stability ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Antibacterial Agents ◽  
Good Thermal Stability ◽  
Polymerization Method

Poly(cyclotriphosphazene-co-4,4’-diaminodiphenyl ether) (PPO) microspheres were prepared via a precipitation polymerization method, using hexachlorocyclotriphosphazene (HCCP) and 4,4’-diaminodiphenyl ether (ODA) as monomers. Silver-loaded PPO (PPOA) microspheres were generated by the in situ loading of silver nanoparticles onto the surface by Ag+ reduction. Our results showed that PPOA microspheres were successfully prepared with a relatively uniform distribution of silver nanoparticles on microsphere surfaces. PPOA microspheres had good thermal stability and excellent antibacterial activity towards Escherichia coli and Staphylococcus aureus. Furthermore, PPOA microspheres exhibited lower cytotoxicity when compared to citrate-modified silver nanoparticles (c-Ag), and good sustained release properties. Our data indicated that polyphosphazene-based PPOA microspheres are promising antibacterial agents in the biological materials field.

scholarly journals Investigation of Nanoparticle Metallic Core Antibacterial Activity: Gold and Silver Nanoparticles against Escherichia coli and Staphylococcus aureus

2021 ◽  
Vol 22 (4) ◽  
pp. 1905
Author(s):  
Jimmy Gouyau ◽  
Raphaël E. Duval ◽  
Ariane Boudier ◽  
Emmanuel Lamouroux
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Metallic Nanoparticles ◽  
Catalytic Reduction ◽  
Gold And Silver Nanoparticles ◽  
High Antibacterial Activity ◽  
Vis Spectroscopy ◽  
Broth Microdilution Method

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.

scholarly journals Green Synthesis, Antioxidant and Antimicrobial Activity of Silver Nanoparticles Using Gnetum africanum Extracts

2021 ◽  
pp. 1-7
Author(s):  
I. M. Uneze ◽  
J. O. Otonko ◽  
A. K. Adigun ◽  
S. J. Adebayo
Keyword(s):  
Escherichia Coli ◽  
Aqueous Solution ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Leaf Extract ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Gram Positive Bacteria

The synthesis and application of nanoparticles is an important area of research that is gaining attention recently. In this recent project, we report the synthesis of silver nanoparticles, AgNP using aqueous solution of silver nitrate and Gnetum africanum leaf extract (reducing agent). The synthesis of AgNP was achieved by mixing aqueous solution of silver nitrate (70ml, 15.75mM) with a solution of Gnetum africanum leaf extract 100 ml) in a reaction flask and allowed to stand for 24 hours in a dark cupboard. A color change from light brown to yellowish brown was observed which indicated that synthesis of silver nanoparticles took place. The presence of AgNP was ascertained using UV-vis spectra analysis and absorption at 442 nm showed the presence of AgNP. The antioxidant assay of both the synthesized AgNP and the leaf extract was determined using DPPH. Antimicrobial activity was conducted using three different organisms which were Staphylococcus aureus, Escherichia coli and Pseudomonas respectively. The antioxidant results using DPPH scavenging ability of AgNp showed that at concentrations of 2mg/ml,1mg/ml and 0.1mg/ml, the percentage inhibition  of  DPPH  by AgNp was 61.69, 53.06 and 38.31 respectively and that of Gnetum africanum leaf extract was 81.32, 78.49, and 58.29 respectively at the same concentrations using Ascorbic acid as a standard. The antimicrobial activity of both the synthesized AgNps and Gnetum Africanum Leaf extract using one gram positive bacteria (Staphylococcus aureus) and two gram negative bacteria (Escherichia coli and Pseudomonas) revealed that the synthesized AgNps showed lesser activity than Gnetumafricanum leaf extract for both the gram positive bacteria (Staphylococcus aureus) and gram negative bacteria (Pseudomonas) and (Escherichia coli). From the above findings, it can be observed that Gnetum Africanum Leaf extract reduced Ag+ to Ag0 and also both the synthesized AgNps and the Gnetum Africanum Leaf extract showed reasonable antioxidant activity against DPPH and antimicrobial activity against the tested microorganisms. This implied that both samples have medicinal values.

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