scholarly journals Characterization, Antimicrobial and Antioxidant evaluation of biofabricated silver nanoparticles from endophytic Pantoea anthophila

2021 ◽  
Author(s):  
C. Nirmala ◽  
M Srid
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Pathogenic Bacteria ◽  
Average Particle Size ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Average Particle ◽  
X Ray ◽  
Uv Visible

Abstract Endophyte mediated nanoparticles fabrication was emerging as a new frontier in nanomedicines that produce high biocompatible and functionalized silver nanoparticles. In this study, silver nanoparticles were successfully biosynthesized from the extracellular extract of endophytic bacterium Pantoea anthophila isolated from the stem of Waltheria indica for the first time. The synthesised nanoparticles were characterized by UV-Visible and Fourier Transform Infra-Red spectroscopy. The structural analysis is done by X-ray diffraction and the stability was studied by dynamic light scattering and particle size analyser. The size and shape were observed by Transmission Electron Microscope, Scanning Electron Microscope and Energy Dispersive X-Ray spectrum. Further, the nanoparticles were evaluated for antimicrobial and antioxidant properties. Synthesized nanoparticle showed a strong absorption band in the UV-Visible range at 410 nm. The average particle size was found to be 16.8 nm with spherical shaped, crystalline nature. Good zones of inhibition at various ranges were detected against a broad range of human pathogenic bacteria and fungi. A strong free radical scavenging activity of silver nanoparticles with IC50 values 30.75, 19.47, 34.59, 41.12, 27.24, 28.16, 36.21 µg/ml was obtained that was comparable to the reference. The study suggests that the silver nanoparticles can be biosynthesised from endophytic P. anthophila metabolites with significant therapeutic potential. With proper validation, the biosynthesised silver nanoparticles can be developed as a promising antiviral and anticancer drug candidate.

scholarly journals Antibacterial and Antioxidant Studies of Green Synthesized Silver Nanoparticles using Azadirachta indica (Neem) Leaf Extract

2021 ◽  
Vol 9 (3) ◽  
pp. 220-226
Author(s):  
Bishow Regmi ◽  
Tirtha Raj Binadi ◽  
Sarb Narayan Jha ◽  
Rajib Kumar Chaudhary ◽  
Bhoj Raj Poudel ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Azadirachta Indica ◽  
Leaf Extract ◽  
Average Particle Size ◽  
Diffusion Method ◽  
Average Particle ◽  
Face Centered Cubic ◽  
X Ray ◽  
Uv Visible

Silver nanoparticles (AgNPs) have been synthesized by green synthesis using Azadirachta indica leaf extract as both reducing and stabilizing agent. Synthesis of colloidal AgNPs was monitored by UV- visible spectroscopy. The UV- visible spectrum showed a peak at 455 nm corresponding to the plasmon absorbance of the silver nanoparticles. Crystallite structure of silver nanoparticles was studied using X-ray diffraction (XRD) analysis which revealed the face-centered cubic structure (FCC) with average particle size of 8.9 nm, calculated using Debye-Scherrer’s equation. Transmission electron microscopy (TEM) image revealed the agglomeration of small grain with particle size ranging from 2 to 14 nm. FCC crystalline nature was also evident from selected area electron diffraction (SAED) analysis. High purity of as-synthesized AgNPs was analyzed using energy dispersive X-ray (EDX) spectroscopy. Band gap energy was calculated to be 2.7 eV from UV- Visible spectra. 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was stabilized by AgNPs which reveals its antioxidant efficacy. Well diffusion method showed 7 mm to 12 mm zone of inhibition (ZOI) against Gram-positive and Gram-negative bacteria, respectively confirming the antibacterial potential of AgNPs. Int. J. Appl. Sci. Biotechnol. Vol 9(3): 220-226.

scholarly journals Preparation of ultrafine iron phosphate micro-powder from phosphate slag

2018 ◽  
Vol 238 ◽  
pp. 02002
Author(s):  
Fangjing Sun ◽  
Yi Zhang ◽  
Jiawei Zhang ◽  
Xixi Yan ◽  
Xiaoyu Liu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Electron Microscope ◽  
Average Particle Size ◽  
Iron Phosphate ◽  
Average Particle ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Phosphate Slag ◽  
Scanning Electron

In this experiment, ultrafine iron phosphate micro-powder was prepared by hydrothermal method which used phosphate slag as an iron source. The effects of reaction temperature, surfactants type and amount on its particle size were explored. The samples were characterized by using Malvern Laser Particle Size Analyzer (MS2000), X-Ray Diffractometer (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX).The results showed that at 160 °C, 1 wt%CTAB, monoclinic iron phosphate micro-powder was obtained with an average particle size about 0.4 μm which also has a good dispersion in aqueous solution.

Biosynthesis of silver nanoparticles by usingGanoderma-mushroom extract

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540047 ◽  
Author(s):  
S. U. Ekar ◽  
Y. B. Khollam ◽  
P. M. Koinkar ◽  
S. A. Mirji ◽  
R. S. Mane ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
Medicinal Mushroom ◽  
Ag Nps ◽  
Transmission Electron ◽  
Uv Visible

Present study reports the biochemical synthesis of silver nanoparticles ( Ag -NPs) from aqueous medium by using the extract of medicinal mushroom Ganoderma, as a reducing and stabilizing agents. The Ag -NPs are prepared at room temperature by the reduction of Ag+to Ag in aqueous solution of AgNO3. The resultant particles are characterized by using UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) measurement techniques. The formation of Ag -NPs is confirmed by recording the UV-visible absorption spectra for surface plasmon resonance (SPR) where peak around 427 nm. The prominent changes observed in FTIR spectra supported the reduction of Ag+to Ag . The morphological features of Ag -NPs are evaluated from HRTEM. The spherical Ag -NPs are observed in transmission electron microscopy (TEM) studies. The particle size distribution is found to be nearly uniform with average particle size of 2 nm. The Ag -NPs aged for 15, 30, 60 and 120 days showed no profound effect on the position of SPR peak in UV-visible studies, indicating the protecting/capping ability of medicinal mushroom Ganoderma in the synthesis of Ag -NPs.

scholarly journals Sargassum Influx on the Mexican Coast: A Source for Synthesizing Silver Nanoparticles with Catalytic and Antibacterial Properties

2021 ◽  
Vol 11 (10) ◽  
pp. 4638
Author(s):  
Jose Luis López-Miranda ◽  
Rodrigo Esparza ◽  
Marlen Alexis González-Reyna ◽  
Beatriz Liliana España-Sánchez ◽  
Angel Ramon Hernandez-Martinez ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Average Particle Size ◽  
Antibacterial Properties ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Parameters ◽  
First Time

This work reports, for the first time, the synthesis of silver nanoparticles using extracts of the species of Sargassum natans and Sargassum fluitans (AgNPs-S). Their antibacterial and catalytic properties are compared with silver nanoparticles obtained by chemical synthesis (AgNPs-C). The characterization of AgNPs-S and AgNPs-C was carried out using ultraviolet–visible spectroscopy (UV–Vis), dynamic light scattering (DLS), zeta potential, a scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis. The synthesis of silver nanoparticles using Sargassum extract was optimized through varying experimental parameters, such as the type of solvent used to prepare the extract, the volume of the extract, and the pH of the system. The most efficient sample (AgNPs-S) was prepared with a water–ethanol-based extract, using a 3:1 volumetric ratio of extract: a precursor salt with the addition of 1 mL of NaOH pH = 14. The AgNPs-C were spherical in shape, with an average particle size of 11.55 nm, while the AgNPs-S were polyhedral shaped, with an average particle size of 26.39 nm. The synthesized AgNPs-S were found to have significantly higher catalytic activity for the degradation of methylene blue and more effective antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa than AgNPs-C.

scholarly journals Rapid Synthesis of Gold Nanoparticles with Ginger Waste using Microwave Irradiation

2019 ◽  
Vol 32 (2) ◽  
pp. 471-476
Author(s):  
G. Bhagavanth Reddy ◽  
B. Rajkumar ◽  
K. Girija Mangatayaru ◽  
T.V.D. Prasad Rao
Keyword(s):  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Microwave Irradiation ◽  
Pathogenic Bacteria ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
The Stability

In the present investigation, synthesis of gold nanoparticles (AuNPs) was carried out with microwave irradiation of HAuCl4 and the extract of ginger waste. Synthesized AuNPs were characterized by various techniques including UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The TEM images revealed that the nanoparticles were spherical in shape and the average particle size of the AuNPs was found to be approximately 6 ± 2 nm. The stability of gold nanoparticles was analyzed by zeta potential measurements. A negative zeta potential value of -18.4 mV indicates the stability of the AuNPs. Further, gold nanoparticles exhibited the excellent catalytic activity in reducing 4-nitrophenol to 4-aminophenol in the presence of NaBH4 (reducing agent), and it was found to depend on the amount of AuNPs and temperature. Gold nanoparticles did not show any significant antibacterial activity against the pathogenic bacteria studied.

scholarly journals Sintesis Nanopartikel Perak Menggunakan Ekstrak Daun Salam (Syzygium polyanthum) Sebagai Bioreduktor Dan Uji Aktivitasnya Sebagai Antioksidan

2019 ◽  
Vol 7 (1) ◽  
pp. 51-60
Author(s):  
Paulina Taba ◽  
Nadya Yuli Parmitha ◽  
Syahruddin Kasim
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Average Particle Size ◽  
Average Diameter ◽  
Average Particle ◽  
X Ray ◽  
Synthesis Of Nanoparticles ◽  
Particle Size Analyzer ◽  
Ic50 Value

Silver nanoparticles have been synthesized by the reduction method using salam leaf extract (Syzygium polyanthum) as a reducing agent. The silver nanoparticles produced were then tested for their activity as antioxidants. The formation of silver nanoparticles was carried out by adding the leaf extract into the solution of AgNO3 and homogenized using a magnetic stirrer. A UV-Vis spectrophotometer was used to confirm the formation of silver nanoparticles. Particle Size Analyzer (PSA), Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD) and Fourir Transform Infra Red (FTIR) spectrometers were used to characterize the nanoparticles produced before being tested for antioxidant activity. The results showed that the absorbance value increased with increasing reaction contact time. The maximum uptake was obtained at wavelengths of 432-446 nm using a UV-Vis spectrophotometer. The particle size was determined using a PSA with an average particle size distribution of 45.7 nm. The average diameter of silver nanoparticles was 10.06 – 13.97 nm and the silver nanoparticles had rod-shapes. Functional groups that play a role in the synthesis of nanoparticles were –OH, –C=O, and –C-O groups. Silver nanoparticles inhibited free radicals as antioxidants with the IC50 value of 582.7 ppm.

scholarly journals Green Synthesized Silver Nanoparticles as Potent Antifungal Agent against Aspergillus terreus Thom

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Faiza Anum ◽  
Khajista Jabeen ◽  
Sumera Javad ◽  
Sumera Iqbal ◽  
Arifa Tahir ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Antifungal Activity ◽  
Aspergillus Terreus ◽  
Average Particle Size ◽  
Acid Hydrazide ◽  
Size Analysis ◽  
Average Particle ◽  
Highly Effective ◽  
Uv Visible

Medicinal plants are composed of a rich pool of biomolecules and have been increasingly recognized for their antimicrobial properties; however, increasing concerns have been put on the bioavailability features. Thus, this study is aimed at exploring the synthesis and characterization of silver nanoparticles synthesized by Chenopodium album L. leaf extract and assessing the antifungal activity against Aspergillus terreus Thom. Plant extract was prepared in methanol to synthetize silver nanoparticles, which were then characterized by Scanning Electron Microscopy (SEM), UV-Visible spectroscopy, and particle size analysis. UV-Visible analysis indicated maximum absorption at 378 nm, and an average particle size was observed as 25.6 nm. Oval to hexagonal shape was observed by SEM. Antifungal activity of silver nanoparticles (1, 1.5, 2, 2.5, 3, and 3.5%) was addressed against A. terreus biomass. At 3.5%, silver nanoparticles revealed to be highly effective, leading to 92% retardation in fungus growth. In next phase, various organic fractions, viz., chloroform, n-butanol, n-hexane, and ethyl acetate, were obtained from plant methanol extract, and the corresponding silver nanoparticles were prepared. These fractions were also assessed for antifungal activity, and n-hexane fraction led to 64% inhibition in A. terreus biomass. Following gas chromatography-mass spectrometry (GC-MS), 18 compounds were identified, namely, 1,3-cyclopentadiene-5-(1 methylethylidene and o-xylene), ethyl benzene, octadecane, nonane, decane, 2-methylheptane, n-hexadecane, 2-methylheptane, and eicosane, along with carbonyl compounds (4,4-dimethyl-3-hexanone) and phenols, like stearic acid, propionic acid hydrazide, and 2,4-di-T-butylphenol. These findings proved that C. album silver nanoparticles are highly effective against A. terreus.

scholarly journals Thermal, Structural, and Physical Properties of Freeze Dried Tropical Fruit Powder

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Athmaselvi ◽  
C. Kumar ◽  
M. Balasubramanian ◽  
Ishita Roy
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Tropical Fruit ◽  
X Ray ◽  
Freeze Dried ◽  
Fruit Powder ◽  
Lcr Meter

This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya) fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.

scholarly journals Preparation of Polyetherimide Nanoparticles by a Droplet Evaporation-Assisted Thermally Induced Phase-Separation Method

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1548
Author(s):  
Peng Zhu ◽  
Huapeng Zhang ◽  
Hongwei Lu
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Phase Separation ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Droplet Evaporation ◽  
Average Particle ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced ◽  
Pei Nanoparticles

The droplet evaporation effect on the preparation of polyetherimide (PEI) nanoparticles by thermally induced phase separation (TIPS) was studied. PEI nanoparticles were prepared in two routes. In route I, the droplet evaporation process was carried out after TIPS. In route II, the droplet evaporation and TIPS processes were carried out simultaneously. The surface tension and shape parameters of samples were measured via a drop shape analyzer. The Z-average particle diameter of PEI nanoparticles in the PEI/dimethyl sulfoxide solution (DMSO) suspension at different time points was tested by dynamic light scattering, the data from which was used to determine the TIPS time of the PEI/DMSO solution. The natural properties of the products from both routes were studied by optical microscope, scanning electron microscope and transmission electron microscope. The results show that PEI nanoparticles prepared from route II are much smaller and more uniform than that prepared from route I. Circulation flows in the droplet evaporation were indirectly proved to suppress the growth of particles. At 30 °C, PEI solid nanoparticles with 193 nm average particle size, good uniformity, good separation and good roundness were obtained. Route I is less sensitive to temperature than route II. Samples in route I were still the accumulations of micro and nanoparticles until 40 °C instead of 30 °C in route II, although the particle size distribution was not uniform. In addition, a film structure would appear instead of particles when the evaporation temperature exceeds a certain value in both routes. This work will contribute to the preparation of polymer nanoparticles with small and uniform particle size by TIPS process from preformed polymers.

scholarly journals Sintesis Nanopartikel Perak Menggunakan Ekstrak Daun Kluwak Pangium edule Reinw Sebagai Bioreduktor dan Uji Aktivitasnya Sebagai Antioksidan

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Indrawati Patabang ◽  
Syahruddin Kasim ◽  
Paulina Taba
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Average Particle ◽  
Result Show ◽  
Ic50 Values ◽  
Show Result

Silver nanoparticles have been synthesized using kluwak leaf extract (Pangium edule Reinw) as bioreductor and antioxidant activity assay. The nanoparticles formed were monitored by observing UV-Vis absorption and characterized by using FTIR, PSA, XRD and SEM instruments. The result of functional group characterization with FTIR show that the functional groups OH, C = O, C-O and CH2 act as Ag+ reducing agent. The size of silver nanoparticles was determined by using Particle Size Analyzer (PSA) and the result show average particle size distribution of 93.2 nm. Morphology of AgNp were observed by Scanning Electron Microscope (SEM) and X-Ray Difraction (XRD) analysis show result of 51,78 nm. The antioxidant activity was shown by in kluwak leaf extract and silver nanoparticles with IC50 values respectively 831,33 ppm dan 1493,09 ppm.

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