scholarly journals Silver Doped Magnesium Ferrite Nanoparticles: Physico-Chemical Characterization and Antibacterial Activity

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2859
Author(s):  
Erika Fantozzi ◽  
Erlinda Rama ◽  
Cinzia Calvio ◽  
Benedetta Albini ◽  
Pietro Galinetto ◽  
...  

Spinel phases, with unique and outstanding physical properties, are attracting a great deal of interest in many fields. In particular, MgFe2O4, a partially inverted spinel phase, could find applications in medicine thanks to the remarkable antibacterial properties attributed to the generation of reactive oxygen species. In this paper, undoped and Ag-doped MgFe2-xAgxO4 (x = 0.1 and 0.3) nanoparticles were prepared using microwave-assisted combustion and sol–gel methods. X-ray powder diffraction, with Rietveld structural refinements combined with micro-Raman spectroscopy, allowed to determine sample purity and the inversion degree of the spinel, passing from about 0.4 to 0.7 when Ag was introduced as dopant. The results are discussed in view of the antibacterial activity towards Escherichia coli and Staphylococcus aureus, representative strains of Gram-negative and Gram-positive bacteria. The sol–gel particles were more efficient towards the chosen bacteria, possibly thanks to the nanometric sizes of metallic silver, which were well distributed in the powders and in the spinel phase, with respect to microwave ones, that, however, acquired antibacterial activity after thermal treatment, probably due to the nucleation of hematite, itself displaying well-known antibacterial properties and which could synergistically act with silver and spinel.

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Cheriti A ◽  
Boukhobza Z ◽  
Boulenouar N ◽  
Djeradi H ◽  
M Kacimi El Hassani ◽  
...  

The essential oil of wild-growing medicinal specie Brocchia cinerea (Asteraceae) from Brezina (Algerian Sahara) was studied for chemical composition by GC/MS analysis and antibacterial activity. Twenty-nine identified components constituted 94.07% of the oil. The most important major components in the oil were trans-Thujone (36.11 %), Camphor (12.08 %), Santolina triene (11.25 %), 1,8-Cineol (6.98 %) and Cis-Verbenyl acetate (6.33 %), together reaching 72.75% of the total oil which is characterized by the presence of high content of oxygenated monoterpenes. The antibacterial activity of the essential oil was tested using the disc diffusion assay. The results showed that the essential oil of Brocchia cinerea had antibacterial activity against all tested Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, and Pseudomonas aereginosa). Keywords: Essential Oil; Brocchia Cinerea; GC/MS; Oxygenated Monoterpenes; Antibacterial activity; Sahara;


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Dan Meng ◽  
Xiuhua Liu ◽  
Yun Xie ◽  
Yang Du ◽  
Yong Yang ◽  
...  

Development of effective antibacterial visible light-activated photocatalytic materials in industries including wastewater treatment and food industry has attracted increasing attention. In this work, Fe-doped TiO2 thin films with different doping levels on a glass substrate were prepared by the sol-gel dip-coating method. The as-prepared films were characterized by Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM). Raman spectroscopy and XRD results show the crystalline phase of titanium dioxide was anatase, and the range of the crystal size for the films was 19.24–22.24 nm. XPS results indicate that iron was in the form of Fe3+ in Fe-doped TiO2 films. Regarding the antibacterial properties of TiO2 films, the order of antibacterial activity of TiO2 films was 0.1 at% Fe > 0.5 at% Fe > 1.0 at% TiO2 > bare TiO2 > 2.0 at% Fe > 3.45 at% Fe. 0.1 at% of Fe is the optimum dopant ratio related to antibacterial activity. 0.1 at% Fe-doped TiO2 film is highly efficient in inactivating E. coli under 3 h of visible light irradiation, and it remains efficient even in real dye waste water.


2018 ◽  
Vol 7 (4) ◽  
pp. 267-271
Author(s):  
Oumaima Karai ◽  
Younas Aouine ◽  
Hassane Faraj ◽  
Alami Anouar ◽  
Mohammed Rachid Kabbour ◽  
...  

The present work covers the recent synthetic of methyl (2R)-2-benzamido-2-{[(1R)-2-methoxy-2-oxo-1-phenylethyl]amino}acetate, via N-alkylation of methyl a-azido glycinate N-benzoylated with methyl 2-amino-2-phenylacetate in methylene chloride and in presence of triethylamine as basic catalyst. The structure of the prepared compound was determined by spectroscopic methods: 1H-NMR, 13C-NMR, MS data, elemental analysis and confirmed by X-Ray diffraction. This compound was screened in vitro for its antibacterial activity against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Salmonella enteric). The MIC values confirmed that the title compound had a bactericidal effect against the strains tested.


Author(s):  
A.A.J.P. Kumara ◽  
D. L. Jayratne ◽  
G. V. Samaranayake

Euphorbia antiquorum is a large shrub or small tree belonging to the largest and the most diverse family in the plant kingdom, Euphorbiaceae. E. antiquram latex was used as a classical binding agent for the kshara sutra in the management of the anal fistula. In the present study, an attempt was made to evaluate the antimicrobial properties of latex of E. antiquorum on certain microbes. The methanolic extract of the latex was prepared. The fractions of methanol extract were tested for their antibacterial activity against the Gram positive bacteria, Streptococus agalactiae and Staphylococcus aureus and Gram negative bacteria Escherichia coli and P. aeruginosa. The results revealed that the latex showed minimum inhibition only to E. coli and S. aureus. Latex did not posses antibacterial activity against S. agalactiae and P. aeruginosa. The results suggest that the E. antiquorum latex extract account for the antibacterial properties and has a potential for use as an antimicrobial agent.


2021 ◽  
pp. 088532822110044
Author(s):  
Haiyang Wang ◽  
Toshinari Maeda ◽  
Toshiki Miyazaki

Bone cement based on poly(methyl methacrylate) (PMMA) powder and methyl methacrylate (MMA) liquid is a very popular biomaterial used for the fixation of artificial joints. However, there is a risk of this cement loosening from bone because of a lack of bone-bonding bioactivity. Apatite formation in the body environment is a prerequisite for cement bioactivity. Additionally, suppression of infection during implantation is required for bone cements to be successfully introduced into the human body. In this study, we modified PMMA cement with γ-methacryloxypropyltrimetoxysilane and calcium acetate to introduce bioactive properties and 2-( tert-butylamino)ethyl methacrylate (TBAEMA) to provide antibacterial properties. The long-term antibacterial activity is attributed to the copolymerization of TBAEMA and MMA. As the TBAEMA content increased, the setting time increased and the compressive strength decreased. After soaking in simulated body fluid, an apatite layer was detected within 7 days, irrespective of the TBAEMA content. The cement showed better antibacterial activity against Gram-negative E. Coli than Gram-positive bacteria; however, of the Gram-positive bacteria investigated, B. subtilis was more susceptible than S. aureus.


2022 ◽  
Vol 23 (1) ◽  
pp. 563
Author(s):  
Valentin Job ◽  
Julie Laloy ◽  
Vincent Maloteau ◽  
Emile Haye ◽  
Stéphane Lucas ◽  
...  

Hospital-acquired infections are responsible for a significant part of morbidity and mortality. Among the possible modes of transmission, this study focuses on environmental surfaces by developing innovative antibacterial coatings that can be applied on interior fittings in hospitals. This work aims to optimize a coating made of an amorphous carbon matrix doped with silver (a-C:H:Ag) produced by a hybrid PVD/PECVD process and to evaluate its antibacterial activity. We present a coating characterization (chemical composition and morphology) as well as its stability in an ageing process and after multiple exposures to bacteria. The antibacterial activity of the coatings is demonstrated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria through several bioassays. Moreover, the data suggest a crucial role of silver diffusion towards the surface and nanoparticle formation to explain the very promising anti-bacterial activities reported in this work.


2020 ◽  
Vol 83 (1) ◽  
pp. 19-25
Author(s):  
Suntini Suntini ◽  
Anastasia Wheni Indrianingsih ◽  
Harjono Harjono

Recently, a wound healing from natural composite with excellent properties is in a high demand. In this study, a novel composite of bacterial cellulose made from Siwalan sap (Borassus flabellifer) was achieved. Siwalan is a common plant in Java Island of Indonesia and the application is very limited for beverage only. This study aims to determine the effect of the AgNO3/NaBH4 concentration ratio in the development of Ag-BC composites and its antibacterial properties from Siwalan sap. Ag-BC composites were prepared by impregnating the silver solution into the BC matrix through the reduction process with NaBH4. Characterization of Ag-BC composites conducted using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX). Antibacterial assay was performed using disc diffusion method against Salmonella typhimurium (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. The characterization of Ag-BC composite shows the nanostructure of BC with a length of fiber around 35-60 nm in width. The SEM-EDX micrograph showed that silver particles were impregnated into the BC matrix. Antibacterial activity test results showed that the Ag-BC composite had the ability to inhibit the bacteria S. typhimurium and S. aureus with good inhibition. This result showed the potential application of Ag-BC composite from Siwalan plant as a natural material for medical and pharmaceutical purpose, especially as an antibacterial agent.


2018 ◽  
pp. 53-60
Author(s):  
Владимир (Vladimir) Александрович (Аleksandrovich) Куркин (Kurkin) ◽  
Татьяна (Tat'yana) Константиновна (Konstantinovna) Рязанова (Ryazanova) ◽  
Александр (Аleksandr) Викторович (Viktorovich) Жестков (Zhestkov) ◽  
Артем (Аrtem) Викторович (Viktorovich) Лямин (Lyamin) ◽  
Елена (Elena) Владимировна (Vladimirovna) Авдеева (Avdeeva) ◽  
...  

The aim of this paper is the isolation of individual compounds, which are caused the antibacterial activity of the leaves of the bearberry [Arctostaphylos uva-ursi (L.) Spreng.]. The leaves of Arctostaphylos uva-ursi, collected in Perm region, there were extracted with 70% ethanol, the obtained water-alcoholic infusion there was evaporated in vacuum.By means of the chromatographic methods with the using of silica gel 40/100 and eluent systems (chloroform and ethanol in several ratio) from the evaporated water-alcoholic extract of the leaves of Arctostaphylos uva-ursi, a substance with antibacterial activity, ethyl ester of p-digallic acid, which is a new natural compound, was isolated along with arbutin ((1-О-b-D-glucopyranoside of hydroquinone) from the leaves of this plant. The chemical structures of the ethyl ester of p-digallic acid and arbutin were established with the using of data of 1H-NMR-spectroscopy, UV-spectroscopy and mass-spectrometry..The antibacterial activity of ethyl ester of p-digallic acid against test cultures of gram-positive bacteria Bacillus cereus and Staphylococcus aureus, gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa for the first time was determined. By antibacterial activity, arbutin was inferior not only to ethyl ester of p-digallic acid, but also to decoction from the leaves of the bearberry. Consequently, the ethyl ester of p-digallic acid is one in main component, which is take the contribution in the antibacterial activity of the decoction and other preparations of the leaves of Arctostaphylos uva-ursi.


Author(s):  
Selma M.H. AL-Jawad ◽  
Zahraa S. Shakir ◽  
Duha S. Ahmed

ZnO/MWCNTs hybrid and doped with different concentration of Nickel element prepared by using Sol-gel been technique reported. All samples were prepared and characterized by X-Ray Diffraction Analysis (XRD), Energy Dispersive X-ray Spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM), and UV-Vis spectroscopy have been identified the structural, optical and morphological properties. X-ray diffraction showed the polycrystalline nature with hexagonal wutzite structure of hybrid and doped with Nickel. The crystalline size of the hybrid nanostructure was increasing from 23.73 nm to 34.59 nm. Besides, the UV-Vis spectroscopy showed a significant decrease in the band gap values from 2.97 eV to 2.01 eV. Whereas the FE-SEM analysis confirm the formation spherical shapes of ZnO NPs deposited on cylindrical tubes representing the MWCNTs. The antibacterial activity reveals that the inhibition zone of Ni doped-ZnO/MWCNTs hybrid was 28.5 mm, 26.5 mm toward E. coli and S. aureus bacteria, respectively.


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