scholarly journals Does the Antibacterial Activity of Silver Nanoparticles Depend on the Shape of the Nanoparticle? A Study of the Gram-Negative Bacterium Escherichia coli

2007 ◽  
Vol 73 (6) ◽  
pp. 1712-1720 ◽  
Author(s):  
Sukdeb Pal ◽  
Yu Kyung Tak ◽  
Joon Myong Song
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Antibacterial Properties ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Energy Filtering ◽  
Transmission Electron ◽  
Triangular Silver Nanoplates ◽  
Liquid Systems ◽  
Biocidal Property

ABSTRACT In this work we investigated the antibacterial properties of differently shaped silver nanoparticles against the gram-negative bacterium Escherichia coli, both in liquid systems and on agar plates. Energy-filtering transmission electron microscopy images revealed considerable changes in the cell membranes upon treatment, resulting in cell death. Truncated triangular silver nanoplates with a {111} lattice plane as the basal plane displayed the strongest biocidal action, compared with spherical and rod-shaped nanoparticles and with Ag+ (in the form of AgNO3). It is proposed that nanoscale size and the presence of a {111} plane combine to promote this biocidal property. To our knowledge, this is the first comparative study on the bactericidal properties of silver nanoparticles of different shapes, and our results demonstrate that silver nanoparticles undergo a shape-dependent interaction with the gram-negative organism E. coli.

Role of Green Silver Nanoparticles in the Inhibition of Listeria monocytogenes and Escherichia coli

2020 ◽  
Vol 10 (1) ◽  
pp. 39-50
Author(s):  
Anvesha Sinha ◽  
Jayanand Manjhi
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Listeria Monocytogenes ◽  
Antibacterial Properties ◽  
Punica Granatum ◽  
Biological Synthesis ◽  
Antibacterial Drug ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative

Background: The quandary of antimicrobial resistance is rapidly becoming a cause for global concern. Meanwhile, green biological synthesis of silver nanoparticles is being extensively studied for their antibacterial properties. However, in the dearth of appropriate and substantial evidence, the development of Green Silver Nanoparticles (GSNPs) as the antibacterial drug is impeded. Objective: The present study aims at surfacing the mechanism behind the inhibitory actions of GSNPs against both gram-positive and gram-negative bacteria. Methods: Silver nanoparticles were fabricated using the peels of Citrus Sinensis and Punica granatum and characterized using UV-Vis Spectrophotometer, XRD, FTIR, SEM and TEM. The GSNPs were further scrutinized for their antibacterial properties against Gran negative Escherichia coli and grampositive Listeria monocytogenes and confirmed using FC analysis. Further multiple parameters were investigated for deciphering the mechanism of antibacterial action. Results: The results reveal the fabrication of 14-60 nm polydispersed GSNPs having 96% inhibition potential against both the test bacteria. Deposition of GSNPs on the bacterial surface resulting in pit formation in the bacterial cell wall and membrane causing leaking of cellular components and deactivation of bacterial enzymes were observed in the present study. Conclusion: The study proves that contrary to earlier investigations, GSNPs prepared using orange and pomegranate peels are effective against both gram positive and gram negative bacteria and may thus be used for the development of antibacterial therapies, subjected to further investigation.

Green synthesised silver nanoparticles incorporated electrospun poly(methyl methacrylate) nanofibers with different architectures for ophthalmologic alternatives

2021 ◽  
Vol 36 (2) ◽  
pp. 93-110
Author(s):  
Princy Philip ◽  
Tomlal Jose ◽  
Sarath KS ◽  
Sunny Kuriakose
Keyword(s):  
Silver Nanoparticles ◽  
Methyl Methacrylate ◽  
Antibacterial Properties ◽  
Analytical Techniques ◽  
Morphological Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Poly Methyl Methacrylate ◽  
Antimicrobial Studies ◽  
Eye Problems

Silver nanoparticles with 5–10 nm diameters are synthesised using Couroupita guianensis flower extract. The synthesised silver nanoparticles found to show good antimicrobial activity against gram negative and gram positive bacteria. Poly(methyl methacrylate) nanofibers with pristine, surface roughened and coaxial hollow forms are prepared by electrospinning. The structural and morphological properties of these pure and structurally modified poly(methyl methacrylate) nanofibers are evidenced by various analytical techniques. The antimicrobial studies of poly(methyl methacrylate) nanofibers having different architectures incorporated with silver nanoparticles are carried out. It is found that, all the three forms of poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show antibacterial properties against both gram positive and gram negative bacteria. Among these, surface roughened poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show highest antibacterial activity than the other two structural forms. The present study offers an alternative to the existing optical lenses. People especially those who suffer from eye problems can protect their eyes in a better way from infectious agents by wearing optical lens made from C. guianensis stabilised silver nanoparticles incorporated poly(methyl methacrylate) nanofibers than that made from pure poly(methyl methacrylate) nanofibers or films.

scholarly journals The Synergistic Effect of Biosynthesized Silver Nanoparticles and Phage ZCSE2 as a Novel Approach to Combat Multidrug-Resistant Salmonella enterica

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Abdallah S. Abdelsattar ◽  
Rana Nofal ◽  
Salsabil Makky ◽  
Anan Safwat ◽  
Amera Taha ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Color Change ◽  
Antibacterial Properties ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Mortality And Morbidity ◽  
Novel Approach ◽  
Transmission Electron

The emergence and evolution of antibiotic-resistant bacteria is considered a public health concern. Salmonella is one of the most common pathogens that cause high mortality and morbidity rates in humans, animals, and poultry annually. In this work, we developed a combination of silver nanoparticles (AgNPs) with bacteriophage (phage) as an antimicrobial agent to control microbial growth. The synthesized AgNPs with propolis were characterized by testing their color change from transparent to deep brown by transmission electron microscopy (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). The phage ZCSE2 was found to be stable when combined with AgNPs. Both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for AgNPs, phage, and their combination. The results indicated that MIC and MBC values were equal to 23 µg/mL against Salmonella bacteria at a concentration of 107 CFU/mL. The combination of 0.4× MIC from AgNPs and phage with Multiplicity of Infection (MOI) 0.1 showed an inhibitory effect. This combination of AgNPs and phage offers a prospect of nanoparticles with significantly enhanced antibacterial properties and therapeutic performance.

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.

Silver Oxide–Copper Oxide Nanocomposite Preparation and Antimicrobial Activity as a Source for the Treatment of Fish Diseases

2017 ◽  
pp. 140-151
Author(s):  
Sayed Reza Shaffiey ◽  
Sayedeh Fatemeh Shaffiey
Keyword(s):  
Aeromonas Hydrophila ◽  
Bacterial Infections ◽  
Antimicrobial Activities ◽  
Cuo Nanoparticles ◽  
Negative Bacterium ◽  
Electron Micrograph ◽  
X Ray Diffraction ◽  
Gram Negative ◽  
Transmission Electron ◽  
Scanning Electron

Aeromonas hydrophila is a heterotrophic, gram negative bacterium which is primary or secondary cause of ulcers, fin rot, tail rot, and hemorrhagic septicaemia in fish. The treatments for this infection are only restricted to some antibiotics. So, novel materials are being searched for combating with bacterial infections and the resulting consequences. In this chapter, Ag2O/CuO nanocomposites were synthesized chemically and characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM) and transmission electron microscope (TEM). The antimicrobial activities of Ag2O/CuO nanoparticles (NPs), was checked by both well diffusion and turbidometric (spectrophotometric) method. Synthesized nanoparticles exhibited their antimicrobial efficacy in both the standard inhibitory assays; these results thus provide a scope for further research on the application of Ag2O/CuO nanoparticles as disinfectant and/or antibiotic in the fishery industry.

scholarly journals Evaluation of Nanocomposite Made of Polylactic Acid and Nanocellulose from Carrot Pomace Modified with Silver Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 812 ◽  
Author(s):  
Monika Szymańska-Chargot ◽  
Monika Chylińska ◽  
Piotr M. Pieczywek ◽  
Anna Walkiewicz ◽  
Giorgia Pertile ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Silver Nanoparticles ◽  
Polylactic Acid ◽  
Cellulose Nanofibrils ◽  
Antibacterial Properties ◽  
Young Modulus ◽  
Transmission Rates ◽  
Degradation Temperature

In this research, it was proposed to use carrot cellulose nanofibrils (CCNF) isolated from carrot pomace modified with silver nanoparticles (AgNPs) as a filler of polylactic acid (PLA) composites matrix. The new procedure was based on two steps: first, the preparation of nanocellulose modified with metal nanoparticles, and then the combination with PLA. Two concentrations—0.25 mM and 2 mM—of AgNO3 were used to modify CCNF. Then, PLA was mixed with the filler (CCNF/AgNPs) in two proportions 99:1 and 96:4. The influence of CCNF/AgNPs on mechanical, hydrophilic, thermal, and antibacterial properties of obtained nanocomposites was evaluated. The greatest improvement of mechanical properties was observed for composite containing CCNF with 2 mM of AgNPs, which obtained the lowest Young modulus and highest strain at break. The degradation temperature was lower for PLA with CCNF/AgNPs, but crystallization temperature wasn’t influenced. The addition of CCNF/AgNPs also increased hydrophilicity. The transmission rates of oxygen, nitrogen, and carbon dioxide also increased after the addition of CCNF/AgNPs to PLA. The antibacterial function against Escherichia coli and Bacillus cereus was obtained after the addition of AgNPs but only at the contact surface with the material made, suggesting the lack of migration of nanoparticles from the composite.

scholarly journals Green Synthesis of Silver Nanoparticles using Salacca zalacca Extract as Reducing Agent and It’s Antibacterial Activity

2019 ◽  
Vol 31 (12) ◽  
pp. 2804-2810
Author(s):  
Anti Kolonial Prodjosantoso ◽  
Oktanio Sigit Prawoko ◽  
Maximus Pranjoto Utomo ◽  
Lis Permana Sari
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Staphylococcus Epidermidis ◽  
Silver Ions ◽  
Reduction Reaction ◽  
Face Centered Cubic ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Face Centered

In this article, the synthesis of silver nanoparticles through a reduction reaction process using Salacca zalacca extract is reported. The AgNPs were characterized using X-ray diffraction, transmission electron microscopy, Fourier transform infrared and UV-visible spectrophotometry methods. The AgNPs antibacterial activity was determined against of Gram-positive bacteria (Staphylococcus epidermidis) and Gram-negative bacteria (Escherichia coli). The main functional groups contained in Salacca zalacca extract are carbonyl, hydroxyl and nitrile groups, which are believed to reduce the silver ions to metal. The surface plasmon resonance values of brownish red AgNPs are in the range of 410 nm to 460 nm. The structure of AgNPs is face centered cubic (FCC). The diameter of silver nanoparticles crystallite is 14.2 ± 2.6 nm. The AgNPs growth inhibition zones of Escherichia coli and Staphylococcus epidermidis are 9.6 mm and 9.2 mm, respectively.

scholarly journals Bactericidal Silver Nanoparticles by Atmospheric Pressure Solution Plasma Processing

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 874 ◽  
Author(s):  
Janith Weerasinghe ◽  
Wenshao Li ◽  
Rusen Zhou ◽  
Renwu Zhou ◽  
Alexander Gissibl ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Atmospheric Pressure ◽  
Chemical Reduction ◽  
Cost Effective ◽  
Pressure Solution ◽  
Gram Negative Bacteria ◽  
Promising Alternative ◽  
Gram Negative ◽  
Transmission Electron ◽  
Solution Plasma Processing

Silver nanoparticles have applications in plasmonics, medicine, catalysis and electronics. We report a simple, cost-effective, facile and reproducible technique to synthesise silver nanoparticles via plasma-induced non-equilibrium liquid chemistry with the absence of a chemical reducing agent. Silver nanoparticles with tuneable sizes from 5.4 to 17.8 nm are synthesised and characterised using Transmission Electron Microscopy (TEM) and other analytic techniques. A mechanism for silver nanoparticle formation is also proposed. The antibacterial activity of the silver nanoparticles was investigated with gram-positive and gram-negative bacteria. The inhibition of both bacteria types was observed. This is a promising alternative method for the instant synthesis of silver nanoparticles, instead of the conventional chemical reduction route, for numerous applications.

Synthesis of Nano-Hydroxyapatite from Snakehead (Channa striata) Fish Bone and its Antibacterial Properties

2020 ◽  
Vol 840 ◽  
pp. 293-299
Author(s):  
Poedji Loekitowati Hariani ◽  
Muryati Muryati ◽  
Muhammad Said ◽  
Salni Salni
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Fish Bone ◽  
Molar Ratio ◽  
Temperature Variations ◽  
Gram Negative ◽  
Fish Bones ◽  
Channa Striata

Nano-hydroxyapatite was synthesized by coprecipitation method and tested its antibacterial properties. Nano-hydroxyapatite was synthesized using CaO precursors from snakehead (Channa striata) fish bones and (NH4)2HPO4. The synthesis was carried out with temperature variations of 30, 60, 80, and 100 °C. Antibacterial activity was determined using two types of bacteria, namely gram-positive and gram-negative. The XRD spectra show that the highest peak is hydroxyapatite synthesized at a temperature of 100 °C. Hydroxyapatite produced from various synthesis temperatures has the size of nanoparticles in the range 37.32-49.27 nm. The nano-hydroxyapatite functional groups are characterized using FTIR, the analysis indicate the presence of OH, CO32‒ and PO43‒. The molar ratio Ca/P is obtained of 1.71 approaching theoretical hydroxyapatite of 1.67. The resulted nano-hydroxyapatite has significant antibacterial properties to Escherichia coli and Staphylococcus aureus.

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