scholarly journals Antimicrobial Application and Assessment of Green Synthesized Silver Nanoparticles Using Aqueous Leaf Extract of Ficus Copiosa

2019 ◽  
Vol 6 (3) ◽  
pp. 06-15
Author(s):  
David Timi ◽  
Subramaniyam Gopalakrishnan ◽  
Macquin Maino
Keyword(s):  
Silver Nanoparticles ◽  
Sem Analysis ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
Agar Disc ◽  
Diffusion Technique ◽  
Aqueous Leaf Extract ◽  
Micro Organisms ◽  
Green Synthesized Silver Nanoparticles

Plant mediated green-synthesized silver nanoparticles (AgNPs) and the bioactivity on pathogenic micro-organisms is discussed. In the present investigation, aqueous leaf extracts of a medicinal plant, Ficus copiosa was utilized to construct AgNPs. The synthesized AgNPs was characterized by Ultraviolet-visible (UV-vis), Fourier Transform-infrared (FT-IR), X-ray Diffraction (XRD) spectrometer and Scanning Electron Microscopy (SEM) analysis. The phytosynthesized AgNPs exhibited comparable antimicrobial activity with two reference antibiotics against five indicator micro-organisms including two gram-positive (G+) bacteria, two gram-negative (G-) bacteria and a Protozoa (Pz). Study of the minimum inhibition concentration shows the two gram-negative bacteria to be more susceptible to AgNPs than the two gram-positive bacteria. The organisms included in the study are namely, B. Subtilis (G+), S. aureus (G+), E. coli (G-), S. pneumonia (G-) and T. vaginalis (Pz). Agar Disc diffusion technique was employed to assess the efficacy of the silver nanoparticles on the micro-organisms.

scholarly journals Biocatalytic and Biological Activities of Cassia Occidentalis Mediated Silver Nanoparticles

2022 ◽  
Vol 19 (1) ◽  
pp. 1712
Author(s):  
Shashika Singh ◽  
Viresh Mohanlall
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Cassia Occidentalis ◽  
Gram Negative ◽  
Transmission Electron ◽  
Scanning Electron

Silver nanoparticles (AgNPs) were synthesized using the leaf extracts from Cassia occidentalis. The reactions were marked by a distinct colour change and the formation of AgNPs was monitored by measuring the UV-Vis spectra. The morphology and crystalline phase of the metal nanoparticles were determined using Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray analysis (EDX) and Fourier-Transform-Infrared Spectroscopy (FTIR). The biocatalytic activity of the AgNPs against nitrifying compounds was determined using 4-nitrophenol and 4-nitroalanine. The biological screening involved analyzing the AgNPs effectiveness against gram-negative and gram-positive bacteria (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus cereus and Enterococcus faecalis). The AgNPs displayed minimal inhibition at low concentrations ranging from 25 to 50 μg/mL. The toxicity of the AgNPs was tested using the brine shrimp assay and was observed as non-toxic with a nearly zero mortality rate. The AgNPs exhibited an antioxidant potential of 70.90 % inhibition at 1000 µg/mL. C. occidentalis is noted as a potential bioresource for synthesizing AgNPs with applications as antibacterial, antioxidant and biocatalytic agents. HIGHLIGHTS The addition of Ag nanoparticles to C. occidentalis plant extracts resulted in the formation of AgNPs-C. occidentalis complexes The AgNPs-C. occidentalis complexes were characterized using Transmission Electron Microscopy, Scanning Electron Microscopy with EDX, UV-Vis spectrophotometry and IR spectroscopy These AgNPs-C. occidentalis complexes were very stable and showed antibacterial activity against a range of tested gram-positive and gram-negative bacteria at low doses, thus proving to be good antimicrobial agents The AgNPs-C. occidentalis complexes showed higher scavenging activity than leaf extracts of C. occidentalis. The AgNPs have increased catalytic ability for the reduction of 4-nitrophenol and 4-nitroalanine after a 30 min time interval GRAPHICAL ABSTRACT

scholarly journals Hydrothermal Green Synthesis of Silver Nanoparticles using Azadirachta indica A. Juss. Fruit Juice for Potential Antibacterial Activity

2018 ◽  
Vol 4 (5) ◽  
pp. 519-523
Author(s):  
K. Ramar ◽  
A. Jafar Ahamed
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Azadirachta Indica ◽  
Ag Nps ◽  
Gram Positive ◽  
Uniform Size ◽  
Gram Negative ◽  
Agar Disc ◽  
Mueller Hinton Agar ◽  
Average Size

This study employed a green, eco-friendly and convenient hydrothermal method for the synthesis of stable silver nanoparticles (Ag NPs) using neem (Azadirachta indica A Juss) fruit extract, which also acts as a reducing and capping agents. Since neem fruits has been found to have various medicinal applications, this fruit has been chosen in this paper to obtain Ag NPs. The Ag NPs were characterized by PXRD, UV–Vis diffuse reflectance spectra (DRS), FTIR, FESEM-EDAX, and HRTEM analysis. UV–Vis DRS spectra studies provided sufficient evidences for the formation of Ag NPs. The major role of functional groups present in the synthesis and stabilization of the NPs was obtained from FTIR studies. The PXRD and HRTEM investigations clearly demonstrated the crystalline nature of the NPs. From the HRTEM images, the Ag NPs were found to be spherical and of nearly uniform size with an average size of 13 nm. Further, Ag NPs were subjected to the agar disc diffusion antimicrobial assay (Mueller–Hinton Agar testing) against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria. The test results showed the potent antibacterial activity of NPs for Gram-positive bacteria is higher than that the Gram- negative bacteria

Green Synthesis of Silver Nanoparticles from Aqueous Leaf Extract of 'Selaginella bryopteris' and Elucidation of its Antimicrobial Activity

2020 ◽  
Vol 16 (4) ◽  
pp. 449-459
Author(s):  
Varsha Yadav ◽  
Neha Kapoor ◽  
Soma M. Ghorai ◽  
Pradeep
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Aqueous Leaf Extract ◽  
Selaginella Bryopteris

Background: Biosynthesis of nanoparticles from aqueous leaf extract of ‘Selaginella bryopteris’ is a green chemistry approach and is considered to be one of the most efficient methods as it is devoid of toxic chemicals as well as provides natural capping agents for the stabilization of synthesized nanoparticles. ‘S.bryopteris’ also known as ‘Sanjeevani’ (in India), is thought to be prospective natural resource that possesses extraordinary pharmaceutical potential. Objective: S. bryopteris is exclusively native to India and has already been known for its expression of stress-associated genes and high levels of protective metabolites of sugars, phenolic compounds, and polyols. Its potential as an antibacterial agent is being elucidated. Methods: Different leaf extract volumes, silver nitrate (AgNO3) concentrations, and reaction time were investigated separately and the optimal conditions for the synthesis of AgNPs were suggested. The resulting AgNPs were characterized by various techniques like Ultraviolet-Visible (UV-Vis) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and XRay Diffraction (XRD). Antibacterial assays were carried out by using both agar disk and well diffusion method. Results: The AgNPs synthesized in this process were found to have efficient antimicrobial activity against both Gram-positive as well as Gram-negative bacteria. The antibacterial efficacy of S. bryopteris was consciously tried on uropathogenic Escherichia coli (Gram-negative bacteria) and Bacillus megaterium (Gram-positive bacteria) which have the self-limiting food poisoning potential along with opportunistic uropathogenic bacterial strains namely Proteus mirabilis (Gram-negative bacteria) and a non-pathogenic Micrococcus luteus (Gram-positive bacteria) for comparison. Conclusion: S. bryopteris mediated silver nanoparticles’ synthesis is attempted for being cost-effective, eco-friendly and safe for human therapeutics.

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

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 Antibacterial activity of royal jelly-mediated green synthesized silver nanoparticles

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Susanna Gevorgyan ◽  
Robin Schubert ◽  
Mkrtich Yeranosyan ◽  
Lilit Gabrielyan ◽  
Armen Trchounian ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Royal Jelly ◽  
Fluorescence Emission ◽  
Spherical Particles ◽  
Ag Nps ◽  
Gram Negative ◽  
Green Synthesized Silver Nanoparticles ◽  
Higher Sensitivity

AbstractThe application of green synthesis in nanotechnology is growing day by day. It’s a safe and eco-friendly alternative to conventional methods. The current research aimed to study raw royal jelly’s potential in the green synthesis of silver nanoparticles and their antibacterial activity. Royal jelly served as a reducing and oxidizing agent in the green synthesis technology of colloidal silver nanoparticles. The UV–Vis maximum absorption at ~ 430 nm and fluorescence emission peaks at ~ 487 nm confirmed the presence of Ag NPs. Morphology and structural properties of Ag NPs and the effect of ultrasound studies revealed: (i) the formation of polydispersed and spherical particles with different sizes; (ii) size reduction and homogeneity increase by ultrasound treatment. Antibacterial activity of different concentrations of green synthesized Ag NPs has been assessed on Gram-negative S. typhimurium and Gram-positive S. aureus, revealing higher sensitivity on Gram-negative bacteria.

Biosynthesis of Silver Nanoparticles by Punica Granatum Peel Extract and their Biological Activity on different Pathogenic Bacteria

2021 ◽  
Vol 19 (9) ◽  
pp. 38-45
Author(s):  
Hussein H. Al-Turnachy ◽  
Fadhilk. alibraheemi ◽  
Ahmed Abd Alreda Madhloom ◽  
Zahraa Yosif Motaweq ◽  
Nibras Yahya Abdulla
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Biological Activity ◽  
Pathogenic Bacteria ◽  
Punica Granatum ◽  
Gram Positive ◽  
Gram Negative ◽  
Inhibition Zones ◽  
Peel Extract

The present study was included the assessment of the antimicrobial activity of AgNPs synthesized by Punica granatum peel extract against pathogenic bacteria by testing warm aqueous P. granatum peel extract and silver nanoparticles. Punica granatum indicated potency for AgNP extracellular nanobiosynthesis after addition of silver nitrate (AgNO3) 4mM to the extract supernatant, in both concentrations (100mg and 50mg). The biogenic AgNPs showed potency to inhibit both gram-negative and gram-positive bacterial growth. Zons of inhibition in (mm) was lesser in gram-positive than gram-negative bacteria. The resulted phytogenic AgNPs gave higher biological activity than warm aqueous Punica granatum peel extract. The inhibition zone of the phytogenic AgNPs on E. coli reached 17.53, 22.35, and 26.06 mm at (0.1, 0.5, and 1) mg/ml respectively. While inhibition zones of Punica warm aqueous extract reached 5.33, 10.63, and 16.08 mm at the same concentrations. phytogenic AgNPs gave smaller inhibition zones in gram-positive than gram- negative. Cytotoxic activity of the phytogenic AgNPs was assayed in vitro agaist human blood erythrocytes (RBCs), spectroscopic results showed absorbance at 540 nm hemolysis was observed. In general, AgNPs showed least RBCs hemolysis percentage, at 1 mg/ml concentration, hemolysis percentage was (4.50%). This study, concluded that the Punica granatum peel extract has the power of synthses of AgNPs characterized by broad spectrum antimicrobial activity with cyto-toxicity proportional to AgNPs concentration.

scholarly journals Biogenic Silver Nanoparticles Conjugated with Nisin: Improving the Antimicrobial and Antibiofilm Properties of Nanomaterials

Chemistry ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 1271-1285
Author(s):  
Patricia Zimet ◽  
Ruby Valadez ◽  
Sofía Raffaelli ◽  
María Belén Estevez ◽  
Helena Pardo ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
Value Added ◽  
Green Technology ◽  
Natural Food ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Biogenic Silver Nanoparticles

Microbial technology offers a green alternative for the synthesis of value-added nanomaterials. In particular, fungal compounds can improve silver nanoparticle production, stabilizing colloidal nanoparticles. Based on a previous study by our group, silver nanoparticles obtained using the extracellular cell-free extracts of Phanerochaete chrysosporium (PchNPs) have shown antimicrobial and antibiofilm activity against Gram-negative bacteria. Moreover, nisin—a bacteriocin widely used as a natural food preservative—has recently gained much attention due its antimicrobial action against Gram-positive bacteria in biomedical applications. Therefore, the aim of this work was to conjugate biogenic silver nanoparticles (PchNPs) with nisin to obtain nanoconjugates (PchNPs@nis) with enhanced antimicrobial properties. Characterization assays were conducted to determine physicochemical properties of PchNPs@nis, and also their antibacterial and antibiofilm activities were studied. The formation of PchNPs@nis was confirmed by UV-Vis, TEM, and Raman spectroscopy analysis. Different PchNPs@nis nanobioconjugates showed diameter values in the range of 60–130 nm by DLS and surface charge values between −20 and −13 mV. Nisin showed an excellent affinity to PchNPs, with binding efficiencies higher than 75%. Stable synthesized PchNPs@nis nanobioconjugates were not only able to inhibit biofilm formation by S. aureus, but also showed inhibition of the planktonic cell growth of Staphyloccocus aureus and Escherichia coli, broadening the spectrum of action of the unconjugated antimicrobials against Gram-positive and Gram-negative bacteria. In conclusion, these results show the promising application of PchNPs@nis, prepared via green technology, as potential antimicrobial nanomaterials.

scholarly journals Anticancer and Antimicrobial Activity Evaluation of Cowpea-Porous-Starch-Formulated Silver Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shiara Ramdath ◽  
John Mellem ◽  
Londiwe Simphiwe Mbatha
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Cell Viability ◽  
High Dose ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Anticancer Drug Delivery ◽  
Ic50 Values ◽  
Biosynthesized Agnps

Health issues involving inadequate treatment of diseases such as cancer and microbial infections continue to be the subject of much ongoing recent research. Biosynthesized silver nanoparticles (AgNPs) were characterized using Transmission Electron Microscopy (TEM), Zeta Sizer, Ultraviolet (UV), and Fourier Transform Infrared (FTIR) spectroscopy. Their antimicrobial activity was evaluated on selected Gram-positive and Gram-negative bacterial strains, using the disc diffusion and broth dilution assays. Cell viability profiles were evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and apoptosis studies on selected human noncancer and cancer cells. The biosynthesized AgNPs were evaluated to be spherical clusters, with sizes between 40 and 70 nm. The absorption peak at 423 nm and the presence of polyphenols confirmed the synthesis and stabilization of these tested AgNPs. The AgNPs showed a good stability of −23.9 ± 1.02 mV. Good antimicrobial activity (6.0–18.0 mm) was seen on all tested bacteria at a minimum inhibitory concentration (MIC) ranging from 5 to 16 μg/ml, with the highest activity seen against Gram-negative Escherichia coli (18 ± 0.5 mm), and the lowest activity was seen against Gram-positive Listeria monocytogenes (6.0 ± 0.4 mm) after treatment with the AgNPs. These NPs showed a concentration-dependent and cell-specific cytotoxicity with low IC50 values (41.7, 56.3, and 63.8 μg/ml). The NPs were well tolerated by tested cells as indicated by a more than 50% cell viability at the high dose tested and low apoptotic indices (<0.2). These findings indicated that these biosynthesized AgNPs showed great potential as effective antibacterial agents and anticancer drug delivery modalities.

scholarly journals The Efficacy of Psidium guajava Linn Leaf Extractsfrom Selangor Region Against Gram-Positive and Gram-Negative Bacteria

2018 ◽  
Vol 54 (4) ◽  
pp. 294
Author(s):  
S Zuhaira ◽  
Noorhaniz Mohd Nizam ◽  
PM Ridzuan
Keyword(s):  
Methanol Extract ◽  
Psidium Guajava ◽  
Diffusion Method ◽  
Future Research ◽  
Phytochemical Analysis ◽  
Gram Negative Bacteria ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
Freeze Dried

Antibiotic is a type of medication that helps in fighting bacterial infection. Treating bacterial infections in clinical setting become more complicated and costly due to drug resistance. This study was conducted to determine the antibacterial potential of Psidium guajava Linn leaf extracts against Gram-positive and Gram-negative bacteria. P. guajava Linn leaf was obtained from Research Orchards at University Putra Malaysia (UPM). Leaves were extracted using three types of extracts; hot, cold and methanol extract. Freeze dried was used in this study and temperature was set at -104°C for 24 hours. Antibacterial testing was determined using disc diffusion and well diffusion method. Antibacterial activity was evaluated by measuring the inhibitory zone of the tested bacteria. Phytochemical analysis was conducted by adding few drop of diluted NaOH (Sodium Hydroxide) solution to detect the active flavanoid from leaves extract. Antimicrobial activity showed all extracts were effective against Gram-positive and Gram-negative bacteria. Phytochemical analysis of P. guajava Linn leaf extracts showed the methanol extract indicating the presence of tannins, phenols, flavonoids, terpenoids, glycosides and saponins. Results showed that P. guajava Linn leaf was effective against Gram-positive and Gram-negative bacteria, and pythochemical analysis also exhibited a few active compounds that were determined. P. guajava Linn leaf had potential natural product that may be used for further analysis in the future research.

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