scholarly journals Biosynthesis and characterization of iron nanoparticles produced by Thymus vulgaris L. and their antimicrobial activity

2020 ◽  
Vol 79 (2) ◽  
pp. 114-120
Author(s):  
Ramy Sayed Yehia ◽  
Ali Mohammed Ali
Keyword(s):  
Electron Microscopy ◽  
Antimicrobial Activity ◽  
Iron Nanoparticles ◽  
Chemical Reduction ◽  
Nanoparticle Synthesis ◽  
Thymus Vulgaris ◽  
Metallic Ions ◽  
Leaf Extracts ◽  
Vis Spectroscopy

Research in the area of nanoparticles has grown considerably in recent years. Plant leaf extracts provide a platform for nanoparticle synthesis from metal and metal oxides, which is more economical and environmentally friendly than other methods, such as chemical reduction and physical methods. The present study conducted the biosynthesis of iron nanoparticles (FeNPs) using Thymus vulgaris L. (Thyme) leaf aqueous extract. The characterization of FeNPs was carried out by transmission electron microscopy (TEM), UV-visible spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-Ray diffraction (XRD) techniques. UV-vis spectroscopy analysis demonstrated a visible peak around 440 nm. FTIR demonstrated the presence of iron metallic ions. Structural analysis of the nanoparticles by TEM showed agglomerations of spherical shapes. The average size of the synthesized FeNPs was around 40 nm. Regarding application, the ability of the FeNPs to degrade methyl orange was recorded as 95%. They were also examined for potential antimicrobial activity against pathogenic Gram-positive and Gram-negative bacteria and fungi. FeNPs demonstrated high antifungal activity against Candida albicans, C. parapsilosis and Aspergillus flavus, while their antibacterial activity was much weaker compared to commercial antibacterial agent. Thus, FeNPs synthesized using T. vulgaris could play an important role in controlling C. albicans, C. parasilosis and A. flavus and bioremediation of dyes.

Structural Characterization of Iron Nanoparticles Synthesized by Chemical -Methods

2012 ◽  
Vol 1372 ◽  
Author(s):  
A. Ruíz-Baltazar ◽  
Claudia López ◽  
R. Pérez ◽  
G. Rosas
Keyword(s):  
Iron Nanoparticles ◽  
Chemical Reduction ◽  
Vinyl Pyrrolidone ◽  
Synthesis Methods ◽  
Transmission Electron ◽  
Metallic Salt ◽  
Vis Spectroscopy ◽  
Chloride Hexahydrate ◽  
Poly Vinyl Pyrrolidone

ABSTRACTDifferent synthesis methods has been employed to produce nanoparticles, however, chemical reduction method offer a effective route to obtained sizes nanoparticles controlled and morphologies very well defined. Iron nanoparticles were synthesized by chemical reduction using sodium borohydride (SB) NaBH4, Fe (III) Chloride hexahydrate (FeCl3·6H2O) as starting metallic salt (MS) and Poly-vinyl pyrrolidone (PVP) as surfactant agent. The nanoparticles have been characterized by transmission electron microscopy (TEM) and UV-Vis spectroscopy.

scholarly journals Synthesis and characterization of Fe, Co, and Ni colloids in 2-mercaptoethanol

2020 ◽  
Vol 10 ◽  
pp. 184798042096688
Author(s):  
Galo Cárdenas-Triviño ◽  
Sergio Triviño-Matus
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Colloidal Dispersions ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Chemical Liquid Deposition ◽  
Liquid Deposition

Metal colloids in 2-mercaptoethanol using nanoparticles (NPs) of iron (Fe), cobalt (Co), and nickel (Ni) were prepared by chemical liquid deposition method. Transmission electron microscopy, electron diffraction, UV-VIS spectroscopy, and scanning electron microscopy with electron dispersive X-ray spectroscopy characterized the resulting colloidal dispersions. The NPs exhibited sizes with ranges from 9.8 nm for Fe, 3.7 nm for Co, and 7.2 nm for Ni. The electron diffraction shows the presence of the metals in its elemental state Fe (0), Co (0), and Ni (0) and also some compounds FeO (OH), CoCo2S4, and NiNi2S4.

scholarly journals Green Synthesis of Iron Nanoparticles by Acacia nilotica Pods Extract and Its Catalytic, Adsorption, and Antibacterial Activities

2018 ◽  
Vol 8 (10) ◽  
pp. 1922 ◽  
Author(s):  
Enshirah Da’na ◽  
Amel Taha ◽  
Eman Afkar
Keyword(s):  
Electron Microscopy ◽  
Iron Nanoparticles ◽  
Antibacterial Activities ◽  
Acacia Nilotica ◽  
Opportunistic Pathogens ◽  
X Ray Diffraction ◽  
Gram Positive Bacteria ◽  
Vis Spectroscopy ◽  
Adsorption Processes ◽  
Oxidation Degradation

Iron nanoparticles (FeNP) were synthesized using Acacia nilotica seedless pods extract. The synthesized FeNP were characterized by Fourier transform infrared (FTIR), UV/Vis spectroscopy, dynamic light scattering (DLS), electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The XRD pattern confirmed the synthesis of crystalline phase of α-Fe2O3. EDS spectroscopy showed the presence of elemental iron and oxygen, indicating that the nanoparticles are essentially present in oxide form. UV absorption in the range of 450–550 nm confirmed the formation of FeNP. DLS indicated an average FeNP particle size of 229 nm. The synthesized FeNP was tested for adsorption and oxidation degradation of methyl orange (MO) under different conditions and found to be effective in both degradation and adsorption processes. Furthermore, the synthesized FeNP has the potential to terminate the pathogenicity of several human opportunistic pathogens; belongs to gram-negative and gram-positive bacteria and one species of Candida as well.

Study on Dispersion and Characterization of Functionalized MWCNTs Prepared by Wet Oxidation

2014 ◽  
Vol 661 ◽  
pp. 8-13 ◽  
Author(s):  
Intan Syaffinazzilla Zaine ◽  
N.A.M. Napiah ◽  
Azmi Mohamad Yusof ◽  
A.N. Alias ◽  
A.M.M. Ali ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Relative Intensity ◽  
Colloidal Stability ◽  
Structural Defects ◽  
Wet Oxidation ◽  
Defect Level ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Functionalized Mwcnts

The MWCNTs was functionalized by refluxing commercial MWCNTs (a-MWCNTs) in concentrated HNO3/H2SO4 (3:1 v/v) at 100°C for 6 hours. The dispersion of a-MWCNTs and functionalized MWCNTs (f-MWCNTs) were observed after 1 hour sonication in ethanol. Both samples were characterized by UV-vis spectroscopy for dispersion behavior. The dried f-MWCNTs and a-MWCNTs were characterized by Raman spectroscopy to estimate the defect level. The morphology of the samples were analyzed by Transmission Electron Microscopy (TEM). The f-MWCNTs was well dispersed in ethanol within 2 weeks of observations period. The colloidal stability of a-MWCNTs was low as it was easily sediment after 24 hours. The UV-vis spectra of f-MWCNTs show maximum absorbance at 250 nm meanwhile no absorbance was observed for a-MWCNTs. Analysis from Raman spectrum shows that the f-MWCNTs have relative intensity of 1.101 which is higher than a-MWCNTs that have relative intensity of 0.935. The image from TEM revealed that the f-MWCNTs have structural defects and the absence of amorphous carbon on sidewall meanwhile the a-MWCNTs indicate otherwise.

Facile synthesis of water-soluble graphene-based composite: Non-covalently functionalized with chitosan-ionic liquid conjugation

2016 ◽  
Vol 09 (03) ◽  
pp. 1650045 ◽  
Author(s):  
Pei-Ying Li ◽  
Kai-Yu Cheng ◽  
Xiu-Cheng Zheng ◽  
Pu Liu ◽  
Xiu-Juan Xu
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Chemical Reduction ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Text Interaction

Chitosan-ionic liquid conjugation (CILC), which was prepared through the reaction of 1-(4-bromobutyl)-3-methylimidazolium bromide (BBMIB) with chitosan, was firstly used to prepare functionalized graphene composite via the chemical reduction of graphene oxide (GO). The obtained water soluble graphene-based composite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible (UV–Vis) spectroscopy and so on. CILC-RGO showed excellent dispersion stability in water at the concentration of 2.0 mg/mL, which was stable for several months without any precipitate. This may be ascribed to the electrostatic attraction and [Formula: see text]–[Formula: see text] interaction between CILC and graphene.

scholarly journals Evaluation of Antibacterial Potential of Biosynthesized Plant Leave Extract Mediated Titanium Oxide Nanoparticles using Hypheae Thiebeace and Anannos Seneglensis

2019 ◽  
Vol 23 (10) ◽  
pp. 1795-1804
Author(s):  
H. Hassan ◽  
K.I. Omoniyi ◽  
F.G. Okibe ◽  
A.A. Nuhu ◽  
E.G. Echioba
Keyword(s):  
Antimicrobial Activity ◽  
Green Synthesis ◽  
Titanium Oxide ◽  
Microbial Inactivation ◽  
Oxide Nanoparticles ◽  
Leaf Extracts ◽  
Titanium Oxide Nanoparticles ◽  
Tio2 Nps ◽  
Complete Inactivation ◽  
Vis Spectroscopy

The need for new antimicrobial agent has drawn attention on developing new and emerging materials based on nanoparticles with antimicrobial activity. The aim of this research was to evaluate the antibacterial activity of nanoparticles of titanium dioxide. A green synthesis of TiO2 nanoparticles was done using a plant extract of H. thelbiecea and Ananos seneglensisa The presence of various photochemical like flavonoids, steroids, polyphenols, and terpenoids was investigated by following standard biochemical methods. The titanium oxide nanoparticles (TiO2 NPs) synthesized was confirmed by their change of colour to brown and reddish brown due to the phenomenon of surface Plasmon resonance. The characterization studied was done by UV-vis spectroscopy, scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Fourier Transmission infrared spectroscopy (FTIR). The green synthesized TiO2 NPs excitation was confirmed using UV–Vis spectrophotometer at 270 and 290 nm. SEM revealed that the synthesized TiO2 NPs are spherical and crystalline in nature. The overall sizes are 40 and 50 nm for H. thelbiecea and Ananos respectively. FTIR spectroscopy analysis showed the presence of flavonoid, polyphenols and amide groups likely to be responsible for the green synthesis of titanium oxide nanoparticles using H. thelbiecea and Ananos seneglensis aqueous leaf extracts .The XRD pattern showed the characteristic Bragg peaks of (111), (200), (220) and (311) facets of the anatase titanium oxide nanoparticles and confirmed that these nanoparticles are crystalline and spherical in nature. The two plants used to synthesized titanium oxide nanoparticle (H. thelbiecea and ananos seneglensisa) showed good antimicrobial activity against clinically important pathogens.. The antimicrobial study of TiO2 NPs shows that 20 μg/ml TiO2 NPs is effective for complete inactivation of Gram positive, Gram negative as well as fungal cultures. This effective microbial inactivation is mainly attributed to its ability to cause damage to the cell membrane.Keywords: Titanium oxide, phytochemicals, antimicrobial activity, H. thelbiecea, Ananos seneglensisa

The Aggregation Study and Characterization of Silver Nanoparticles

2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Average Particle Size ◽  
Average Particle ◽  
Transmission Electron ◽  
Vis Spectroscopy

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.

Ammonia Gas Sensor Based on Aniline Reduced Graphene Oxide

2013 ◽  
Vol 669 ◽  
pp. 79-84 ◽  
Author(s):  
Xiao Lu Huang ◽  
Nan Tao Hu ◽  
Yan Yan Wang ◽  
Ya Fei Zhang
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Chemical Reduction ◽  
Electrode Arrays ◽  
Ammonia Gas ◽  
Reduced Graphene ◽  
Vis Spectroscopy ◽  
Drop Drying

Here we demonstrate a promising gas sensor based on aniline reduced graphene oxide (RGO), which is fabricated through drop drying RGO nanosheets suspension between the electrode arrays to create conductive networks. RGO, as the sensing materials, which is prepared via the chemical reduction of graphene oxide (GO) by aniline, has been characterized by infrared spectroscopy, UV-Vis spectroscopy, transmittance electron microscopy and scanning electron microscopy. The sensing properties of RGO have also been studied, and the results show that RGO reduced from aniline (RGO-A) exhibits an excellent response to ammonia gas (NH3). Comparing with the RGO reduced from hydrazine (RGO-H) and polyaniline (PANI) nanofiber, the RGO-A exhibits a much better response to NH3 gas. The response of the sensor based on RGO-A to 50 ppm NH3 gas exhibits about 9.2 times and 3.5 times higher than those of the device based RGO-H and PANI nanofiber respectively. In addition, the RGO-A sensor exhibits an excellent repeatability and selectivity to NH3 gas. The oxidized aniline, i.e., polyaniline, which is attached on the surface of RGO sheets through π–π interaction, plays important roles in the final sensing performance of the device, and benefits for the application of the sensor in the field of NH3 gas detection.

Synthesis and Characterization of Nanostructured TiO2-SnO2 Composite

2014 ◽  
Vol 975 ◽  
pp. 233-237
Author(s):  
Joelma C. S. Breve ◽  
Dayse I. dos Santos
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Thermal Analysis ◽  
Gas Sensors ◽  
Catalytic Properties ◽  
Rutile Phase ◽  
Synthesis And Characterization ◽  
Vis Spectroscopy ◽  
Scanning Electron

Nanostructured composites based on titanium dioxide have been studied in order to improve optical and photo-catalytic properties, as well as their performance in gas sensors. In this work, titanium and tin dioxides were simultaneously synthesized by the polyol method resulting in TiO2 platelet coated with SnO2 nanoparticles as was observed by scanning electron microscopy. The thermal analysis showed that the combined synthesis promotes more easily the crystallization of the TiO2 rutile phase. The composite obtained after heat treatment at 500 °C showed to be formed of almost only rutile phases of both oxides. The optical properties analyzed by UV-Vis spectroscopy showed that the combined oxides have higher absorbance, which reinforces a model found in the literature based on the flow of photo-generated electrons to the conduction band of SnO2 delaying the recombination of charges.

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