scholarly journals Study on Synthesis and Antibacterial Properties of Ag NPs/GO Nanocomposites

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Huang ◽  
Hongtao Yang ◽  
Yanhua Zhang ◽  
Wei Xiao
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Structure Characterization ◽  
Synthesis Process ◽  
Phase Method ◽  
Ag Nps ◽  
Selected Area Electron Diffraction ◽  
20 Nm

Using graphene oxide as substrate and stabilizer for the silver nanoparticles, silver nanoparticles-graphene oxide (Ag NPs/GO) composites with different Ag loading were synthesized through a facile solution-phase method. During the synthesis process, AgNO3on GO matrix was directly reduced by NaBH4. The structure characterization was studied through X-ray diffraction (XRD), atomic force microscopy (AFM), high-resolution transmission electron microscope (HRTEM), ultraviolet-visible spectroscopy (UV-Vis), and selected area electron diffraction (SAED). The results show that Ag nanoparticles (Ag NPs) with the sizes ranging from 5 to 20 nm are highly dispersed on the surfaces of GO sheets. The shape and size of the Ag NPs are decided by the volume of initial AgNO3solution added in the GO. The antibacterial activities of Ag NPs/GO nanocomposites were investigated and the result shows that all the produced composites exhibit good antibacterial activities against Gram-negative (G−) bacterial strainEscherichia coli(E. coli) and Gram-positive (G+) strainStaphylococcus aureus(S. aureus). Moreover, the antibacterial activities of Ag NPs/GO nanocomposites gradually increased with the increasing of volume of initial AgNO3solution added in the GO and this improvement of the antibacterial activities results from the combined action of size effect and concentration effect of Ag NPs in Ag NPs/GO nanocomposites.

scholarly journals Green Synthesis of Silver Nanoparticles by Extracellular Extracts from Aspergillus japonicus PJ01

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4479
Author(s):  
Pei-Jun Li ◽  
Jiang-Juan Pan ◽  
Li-Jun Tao ◽  
Xia Li ◽  
Dong-Lin Su ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Antibacterial Activities ◽  
Synthesis Process ◽  
Biological Synthesis ◽  
X Ray Diffraction ◽  
Aspergillus Japonicus ◽  
Transmission Electron ◽  
Naoh Solution

The present study focuses on the biological synthesis, characterization, and antibacterial activities of silver nanoparticles (AgNPs) using extracellular extracts of Aspergillus japonicus PJ01.The optimal conditions of the synthesis process were: 10 mL of extracellular extracts, 1 mL of AgNO3 (0.8 mol/L), 4 mL of NaOH solution (1.5 mol/L), 30 °C, and a reaction time of 1 min. The characterizations of AgNPs were tested by UV-visible spectrophotometry, zeta potential, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric (TG) analyses. Fourier transform infrared spectroscopy (FTIR) analysis showed that Ag+ was reduced by the extracellular extracts, which consisted chiefly of soluble proteins and reducing sugars. In this work, AgNO3 concentration played an important role in the physicochemical properties and antibacterial properties of AgNPs. Under the AgNO3 concentration of 0.2 and 0.8 mol/L, the diameters of AgNPs were 3.8 ± 1.1 and 9.1 ± 2.9 nm, respectively. In addition, smaller-sized AgNPs showed higher antimicrobial properties, and the minimum inhibitory concentration (MIC) values against both E. coli and S. aureus were 0.32 mg/mL.

Enhanced catalytic and antibacterial activities of silver nanoparticles immobilized on poly(N-vinyl pyrrolidone)-grafted graphene oxide

RSC Advances ◽  
2015 ◽  
Vol 5 (100) ◽  
pp. 81994-82004 ◽  
Author(s):  
Shikha Singh ◽  
Ravi Kumar Gundampati ◽  
Kheyanath Mitra ◽  
K. Ramesh ◽  
Medicherla V. Jagannadham ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Ag Nanoparticles ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Vinyl Pyrrolidone

PNVP grafted on GO regulates the size of Ag nanoparticles and enhances the catalytic and antibacterial properties along with increase in the dispersibility of GO.

scholarly journals A Facile Method for the Fabrication of Silver Nanoparticles Surface Decorated Polyvinyl Alcohol Electrospun Nanofibers and Controllable Antibacterial Activities

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2486 ◽  
Author(s):  
Yan Yang ◽  
Zhijie Zhang ◽  
Menghui Wan ◽  
Zhihua Wang ◽  
Xueyan Zou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Polyvinyl Alcohol ◽  
Size Distribution ◽  
Antibacterial Properties ◽  
Electrospun Nanofibers ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Ag Nps ◽  
Particles Size Distribution

Polyvinyl alcohol (PVA) electrospun nanofibers (NFs) are ideal carriers for loading silver nanoparticles (Ag NPs) serving as antibacterial materials. However, it is still a challenge to adjust the particles size, distribution, and loading density via a convenient and facile method in order to obtain tunable structure and antimicrobial activities. In this study, Ag NPs surface decorated PVA composite nanofibers (Ag/PVA CNFs) were fabricated by the solvothermal method in ethylene glycol, which plays the roles of both reductant and solvent. The morphology and structure of the as-fabricated Ag/PVA CNFs were characterized by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, X-ray diffraction, UV-visible spectroscopy, and Fourier transform infrared spectroscopy. Ag NPs had an average diameter of 30 nm, the narrowest size distribution and the highest loading density were successfully decorated on the surfaces of PVA NFs, at the AgNO3 concentration of 0.066 mol/L. The antibacterial properties were evaluated by the methods of absorption, turbidity, and growth curves. The as-fabricated Ag/PVA hybrid CNFs exhibit excellent antimicrobial activities with antibacterial rates over 98%, especially for the sample prepared with AgNO3 concentration of 0.066 mol/L. Meanwhile, the antibacterial effects are more significant in the Gram-positive bacteria of Staphylococcus aureus (S. aureus) than the Gram-negative bacteria of Escherichia coli (E. coli), since PVA is more susceptive to S. aureus. In summary, the most important contribution of this paper is the discovery that the particles size, distribution, and loading density of Ag NPs on PVA NFs can be easily controlled by adjusting AgNO3 concentrations, which has a significant impact on the antibacterial activities of Ag/PVA CNFs.

scholarly journals Synthesis of silver nanoparticle-decorated hydroxyapatite (HA@Ag) poriferous nanocomposites and the study of their antibacterial activities

RSC Advances ◽  
2018 ◽  
Vol 8 (73) ◽  
pp. 41722-41730 ◽  
Author(s):  
Zhihui Ni ◽  
Xiuxian Gu ◽  
Yali He ◽  
Zhihua Wang ◽  
Xueyan Zou ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Ag Nps

We demonstrate a facile and green rapid approach for the synthesis of uniform poriferous hydroxylapatite (HA) and poriferous silver nanoparticles (Ag NPs)-decorated hydroxylapatite (HA@Ag) nanocomposites with excellent antibacterial properties.

scholarly journals Microwave-Assisted Green Synthesis of Silver Nanoparticles Using Juglans regia Leaf Extract and Evaluation of Their Physico-Chemical and Antibacterial Properties

Antibiotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 68 ◽  
Author(s):  
Mahsa Eshghi ◽  
Hamideh Vaghari ◽  
Yahya Najian ◽  
Mohammad Najian ◽  
Hoda Jafarizadeh-Malmiri ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Juglans Regia ◽  
Antibacterial Properties ◽  
Infrared Analysis ◽  
Ag Nps ◽  
Stabilizing Agents ◽  
Agno3 Solution ◽  
Transmission Electron ◽  
Vis Spectroscopy

Silver nanoparticles (Ag NPs) were synthesized using Juglans regia (J. regia) leaf extract, as both reducing and stabilizing agents through microwave irradiation method. The effects of a 1% (w/v) amount of leaf extract (0.1–0.9 mL) and an amount of 1 mM AgNO3 solution (15–25 mL) on the broad emission peak (λmax) and concentration of the synthesized Ag NPs solution were investigated using response surface methodology (RSM). Fourier transform infrared analysis indicated the main functional groups existing in the J. regia leaf extract. Dynamic light scattering, UV-Vis spectroscopy and transmission electron microscopy were used to characterize the synthesized Ag NPs. Fabricated Ag NPs with the mean particle size and polydispersity index and maximum concentration and zeta potential of 168 nm, 0.419, 135.16 ppm and −15.6 mV, respectively, were obtained using 0.1 mL of J. regia leaf extract and 15 mL of AgNO3. The antibacterial activity of the fabricated Ag NPs was assessed against both Gram negative (Escherichia coli) and positive (Staphylococcus aureus) bacteria and was found to possess high bactericidal effects.

scholarly journals Photocatalytic activity and antibacterial properties of linen fabric using reduced graphene oxide/silver nanocomposite

RSC Advances ◽  
2020 ◽  
Vol 10 (68) ◽  
pp. 41600-41611
Author(s):  
A. Farouk ◽  
S. El-Sayed Saeed ◽  
S. Sharaf ◽  
M. M. Abd El-Hady
Keyword(s):  
Silver Nanoparticles ◽  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Antibacterial Properties ◽  
Reduced Graphene ◽  
Silver Nanocomposite ◽  
Linen Fabric

Silver nanoparticles were in situ prepared on the surface of linen fabric coated by graphene oxide (GO).

scholarly journals Biosynthetic potential assessment of four food pathogenic bacteria in hydrothermally silver nanoparticles fabrication

2019 ◽  
Vol 8 (1) ◽  
pp. 629-634 ◽  
Author(s):  
Amir Rahimirad ◽  
Afshin Javadi ◽  
Hamid Mirzaei ◽  
Navideh Anarjan ◽  
Hoda Jafarizadeh-Malmiri
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Pathogenic Bacteria ◽  
Heating Time ◽  
Synthesis Process ◽  
Ag Nps ◽  
Physico Chemical ◽  
Minimum Particle Size ◽  
Particle Size Analyzer

Abstract Silver nanoparticles (Ag NPs) were synthesized using four pathogenic bacterial extracts namely, Bacillus cereus, E. coli, Staphylococcus aureus and Salmonella entericasubsp.enterica. Synthesis process were hydrothermally accelerated using temperature, pressure and heating time of 121°C, 1.5 bar ad 15 min. Physico- chemical characteristics of the fabricated Ag NPs, including, particle size, polydispersity index (PDI), zeta potential, broad emission peak (λmax) and concentration were evaluated using UV-Vis spectrophotometer and dynamic light scattering (DLS) particle size analyzer. Furthermore, main existed functional groups in the provided bacterial extracts were recognized using Fourier transform infrared spectroscopy. The obtained results revealed that two main peaks were detected around 3453 and 1636.5 cm-1, for all bacterial extracts, were interrelated to the stretching vibrations of hydroxyl and amide groups which those had key roles in the reduction of ions and stabilizing of the formed Ag NPs. The results also indicated that, Ag NPs with much desirable characteristics, including minimum particle size (25.62 nm) and PDI (0.381), and maximum zeta potential (-29.5 mV) were synthesized using S. e. subsp. enterica extract. λmax, absorbance and concentration values for the fabricated Ag NPs with this bacterial extract were 400 nm, 0.202% a.u. and 5.87 ppm.

scholarly journals Graphene Oxide Reinforced Polycarbonate Nanocomposite Films with Antibacterial Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
R. Mahendran ◽  
D. Sridharan ◽  
K. Santhakumar ◽  
T. A. Selvakumar ◽  
P. Rajasekar ◽  
...  
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Low Cost ◽  
Thermal Studies ◽  
Composite Films ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Nanocomposite Films ◽  
Matrix Microstructure ◽  
Phase Inversion Technique

The incorporation of carbonaceous nanofillers into polymers can result in significant materials with improved physicochemical properties and novel composite functionalities. In this study, we have fabricated antibacterial, lightweight, transparent, and flexible graphene oxide (GO) reinforced polycarbonate thin films by a facile and low-cost methodology. Solution blending is employed to get a homogeneous mixture of PC-GO composites at various loading of GO, and the thin films are prepared by dry-wet phase inversion technique. Thermal studies and micrographs of the films revealed the incorporation of GO in PC matrix. Microstructure of the thin films showed the homogeneous dispersion of GO at micro- and nanoscales; however, at higher loading of GO (0.7%), significant agglomeration is observed. More importantly, PC-GO composite films exhibited excellent antibacterial activities against E. coli and S. aureus, owing to the antibacterial nature of GO nanoparticles.

scholarly journals Interaction of Silver Nanoparticles with Serum Proteins Affects Their Antimicrobial ActivityIn Vivo

2013 ◽  
Vol 57 (10) ◽  
pp. 4945-4955 ◽  
Author(s):  
Divya Prakash Gnanadhas ◽  
Midhun Ben Thomas ◽  
Rony Thomas ◽  
Ashok M. Raichur ◽  
Dipshikha Chakravortty
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Serum Albumin ◽  
Serum Proteins ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Resistant Bacteria ◽  
Human Society ◽  
Vis Spectroscopy

ABSTRACTThe emergence of multidrug-resistant bacteria is a global threat for human society. There exist recorded data that silver was used as an antimicrobial agent by the ancient Greeks and Romans during the 8th century. Silver nanoparticles (AgNPs) are of potential interest because of their effective antibacterial and antiviral activities, with minimal cytotoxic effects on the cells. However, very few reports have shown the usage of AgNPs for antibacterial therapyin vivo. In this study, we deciphered the importance of the chosen methods for synthesis and capping of AgNPs for their improved activityin vivo. The interaction of AgNPs with serum albumin has a significant effect on their antibacterial activity. It was observed that uncapped AgNPs exhibited no antibacterial activity in the presence of serum proteins, due to the interaction with bovine serum albumin (BSA), which was confirmed by UV-Vis spectroscopy. However, capped AgNPs [with citrate or poly(vinylpyrrolidone)] exhibited antibacterial properties due to minimized interactions with serum proteins. The damage in the bacterial membrane was assessed by flow cytometry, which also showed that only capped AgNPs exhibited antibacterial properties, even in the presence of BSA. In order to understand thein vivorelevance of the antibacterial activities of different AgNPs, a murine salmonellosis model was used. It was conclusively proved that AgNPs capped with citrate or PVP exhibited significant antibacterial activitiesin vivoagainstSalmonellainfection compared to uncapped AgNPs. These results clearly demonstrate the importance of capping agents and the synthesis method for AgNPs in their use as antimicrobial agents for therapeutic purposes.

scholarly journals Fabrication, Characterization, and Antibacterial Properties of Electrospun Membrane Composed of Gum Karaya, Polyvinyl Alcohol, and Silver Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Vinod Vellora Thekkae Padil ◽  
Nhung H. A. Nguyen ◽  
Alena Ševců ◽  
Miroslav Černík
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Polyvinyl Alcohol ◽  
Food Packaging ◽  
Chemical Reduction ◽  
Antibacterial Properties ◽  
Hydroxyl Groups ◽  
Ag Nps ◽  
Gum Karaya ◽  
Nanofiber Membranes

Gum karaya (GK), a natural hydrocolloid, was mixed with polyvinyl alcohol (PVA) at different weight ratios and electrospun to produce PVA/GK nanofibers. An 80 : 20 PVA/GK ratio produced the most suitable nanofiber for further testing. Silver nanoparticles (Ag-NPs) were synthesised through chemical reduction of AgNO3(at different concentrations) in the PVA/GK solution, the GK hydroxyl groups being oxidised to carbonyl groups, and Ag+cations reduced to metallic Ag-NPs. These PVA/GK/Ag solutions were then electrospun to produce nanofiber membranes containing Ag-NPs (Ag-MEMs). Membrane morphology and other characteristics were analysed using scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy, and UV-Vis and ATR-FTIR spectroscopy. The antibacterial activity of the Ag-NP solution and Ag-MEM was then investigated against Gram-negativeEscherichia coliandPseudomonas aeruginosaand Gram-positiveStaphylococcus aureus. Our results show that electrospun nanofiber membranes based on natural hydrocolloid, synthetic polymer, and Ag-NPs have many potential uses in medical applications, food packaging, and water treatment.

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