جستجوی مقالات مرتبط با کلیدواژه « Antibacterial activity » در نشریات گروه « مواد و متالورژی »

The present research presents a simple method for preparing Mg-doped ZnO nanoparticles using the sol-gel technique. The characteristics of the nanoparticles were examined through advanced techniques such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and UV-Vis diffuse reflectance spectroscopy. The resulting Mg-doped ZnO nanoparticles displayed a spherical morphology. The antibacterial activity of these nanoparticles was evaluated. Prepared ZnO had a hexagonal wurtzite crystal structure. The incorporation of Mg into ZnO led to a modification of its band gap from 3.23 eV for pure ZnO and 3.18 eV for doped ZnO. MgO has a wider band gap compared to ZnO, and by doping ZnO with Mg, the band gap of the resulting MgZnO alloy can be adjusted. The results exhibited inhibition sizes of 7.7 mm and 6.1 mm against E. coli and S. aureus, respectively. Following Mg doping, the inhibition zone against E. coli and S. aureus increased to 8.3 mm and 9.1 mm, respectively. The results clearly show that the Mg doping have positive effect on the antimicrobial effects against E. coli and S. aureus bacteria.

Among the various available nanoparticles ‘inorganic nanoparticles’ are more promising due to their wide range of application. MgO Nanoparticles (MgO NPs) is a very important inorganic metal oxide nanoparticle due to their diverse field of applications. There are so many physical and chemical methods are available to fabricate potentially useful MgO NPs. The proposed research work highlighted a novel green synthesis method for the fabrication of MgO NPs by using waste material peanut shell as a precursor. The green synthesized MgO NPs are characterize by the techniques like XRD, SEM, FTIR, UV-Vis Spectroscopy. The green synthesized MgO NPs are crystalline in nature & the tetragonal structure of MgO NPs was determined by XRD, various functional groups present on the surface of the synthesized nanoparticles was determined by FTIR and average particle size of green synthesized MgO NPs is 25-30 nm, found as result by SEM and XRD analysis. Two important applications photocatalytic activity and antibacterial activity of the synthesized nanoparticles was investigated in the proposed research work. The green synthesized MgO NPs show remarkable photo catalytic activity against the Indigo Ceramine and Rhodamine dyes and approximately after 60 min the photocatalyst completely remove the dyes from the solution. The Green synthesized MgO NPs show highest antibacterial activity against the pseudomonas aeruginosa (19 mm) bacteria.

The toxicity, negative side effects, and antimicrobial resistance of synthetic drugs are noticeable. The essential oil has revived in recent decades with a branch of alternative medicine. The aim of this study was to investigate and compare the antimicrobial effect of essential oil of Carian copticum with Body perp disinfectant on human skin. The essential oil was extracted from Trachchipermum Carian copticum seeds and also different concentrations of 25, 50, 100, and 200 ppm of essential oils were prepared. To compare the antimicrobial effect of Carian copticum essential oil with Body prep disinfectant was performed by a qualitative plate well method and quantitative microdilution method. Initial screening before skin disinfection resulted in the isolation of 29 isolates of Staphylococcus epidermidis, 12 isolates of Staphylococcus saprophyticus, 2 isolates of Enterococcus faecalis, 14 isolates of Micrococcus spp, and 9 isolates of diphtheroid and a total of 66 isolates. According to the microdilution method, the highest MIC belonged to Staphylococcus epidermidis with code C5 at 200 ppm and the lowest MIC was related to Staphylococcus epidermidis with code K5 and was equal to 25 ppm. The findings of this study showed that the essential oil of Carian copticum seed, in comparison with disinfectants (Body prep) that have some side effects, was not only effective in controlling clinical skin bacteria, but also had a good shelf life in competition with Body Prep. The results of the present study showed that the essential seed oil of the Carian copticum plant was able to successfully control skin pathogenic bacteria.

The Ag/Co2O3/g-C3N4 as a novel nanocomposite was synthesized using a facile strategy by “one pot” method. The as-prepared nanocomposite was applied to improve the antibacterial effect against Escherichia coli and Staphylococcus aureus bacteria. The nanocomposite was characterized by Fourier transform infrared spectroscopy, X-ray Diffraction, and Scanning Electron Microscopy techniques. The strong interaction beetween the plans of graphitic carbon nitride (g-C3N4) and other particles can be resulted to stable nanocomposite. The zone inhibition of nanocomposite was determined for Gram-positive and Gram-negative bacteria. The findings showed the better activity of as-prepared nanocomposite against Gram negative bacteria rather to Gram positive bacteria. The Ag/Co2O3/g-C3N4 was shown good antibacterial effect compared to g-C3N4 and Ag patricles. Further, Colony Forming Unit was indicated the antibacterial behavior of as-prepared composite. The present study can explain insight into the synthesis of heterojunction composite for disinfection.

In this research, the dependence of CuFe2O4 particle size on the antibacterial properties was investigated. The morphology of the particles was controlled in the presence or lack of sucrose as a novel capping agent. Antibacterial properties of the CuFe2O4 nanoparticles were evaluated using the PVDF or silicon rubber matrices. The crystalline structures of the CuFe2O4 were confirmed by X-ray diffraction (XRD) patterns. The prepared nanostructures were more dissected using field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR), and vibrating sample magnetometer (VSM). Eventually, the copper ferrite particle size effect in PVDF and silicone rubber matrices on the antibacterial activity was investigated. The obtained results revealed significant antibacterial properties for the particles. It was found that decreasing particle size would improve antibacterial properties within both polymeric mediums. This research presents novel separable antibacterial magnetic nanostructure suspended in novel media.

The Nano Hydroxyapatite (HAp), HAp/PEG and HAp/PVP powders derived from both Gastropod shell (natural source) and chemical precursor by the precipitation method were characterized through various characterization techniques such as FT-IR, XRD, SEM-EDX, TEM, Antibacterial activity and SBF analysis. Based on the structural, chemical, morphological and biological characteristics, HAp/PVP from natural and chemical precursors have been compared successfully. Calculated structural parameters, crystallinity index, C/P ratio, morphology, antibacterial activity and SBF analysis of the products show that HAp/PVP-S (derived from a natural source) exhibits good mechanical property, rod like morphology, good antibacterial activity and apatite formation ability at 14 days. EDX analysis also shows the presence of carbon and sodium in HAp/PVP-S. Comparative analysis reveals that characteristics of HAp/PVP-S such as high carbonate content, low crystallite size, poor crystalline nature, presence of trace metal, non-stoichiometric elemental composition and rod like crystals which are matched with the characteristics of biological apatite. Thus, the HAp/PVP-S has the ability to form bone apatite.

Aromatic plants have subscribed to the belief that they can be used in food, perfumery, pharmaceutical and cosmetic products due to their nutritional and biological properties. The present study was designed to examine the chemical composition and antibacterial and analgesic properties of Lavandula stoechas flowers originating Amol, north of Iran for the first time. The essential oil of Lavandula stoechas flowers was obtained by hydrodistillation. Gas chromatography-mass spectrometry examination was used for its analysis. Staphylococcus aureus, Escherichia coli, Salmonella enteritidis and Bacillus subtilis were utilized to evaluate the antibacterial activity of essential oil using agar disk diffusion and microdilution assayes. GC-MS analysis revealed Linalol (35.69%) Borneol (14.99%) and 1,8-Cineole (11.45%) as the main compounds of the oil. Antibacterial assayes of various dilutions of essential oil revealed its remarkable antibacterial activity against gram-positive Staphylococcus aureus. Furthermore, the water and ethanolic extracts inhibited the pain resulting from hot-plate test. The results proposed lavandula stoechas from Amol as an alternative natural bioactive compound which posses antibacterial and analgesic effects to use in pharmaceutical industries.

This study focuses on the physical, magnetic, biological and antibacterial behaviour of cobalt-doped HAp powder samples. Pure and Cobalt- doped HAp nanoparticles were synthesized by hydrothermal method. Calcium nitrate, di- ammonium hydrogen phosphate and cobalt nitrate were used as precursor materials. The synthesized powders were characterized using x-ray diffraction pattern (XRD), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM), Raman spectroscopy as well as MTT assay and cell adhesion test. Disc diffusion method was used to investigate antibacterial activity of the samples. The results confirmed the substitution of Ca by Co ions in the HAp lattice. In addition, this substitution induced size reduction and morphology change in HAp particles. All cobalt substituted HAp powder samples displayed paramagnetic properties, as opposed to the diamagnetic behaviour observed in the pure HAp samples. In addition, these nanoparticles exhibited cell adhesion, biocompatibility and antibacterial activity against S.aureus bacteria.
This study focuses on the physical, magnetic, biological and antibacterial behaviour of cobalt-doped HAp powder samples. Pure and Cobalt- doped HAp nanoparticles were synthesized by hydrothermal method. Calcium nitrate, di- ammonium hydrogen phosphate and cobalt nitrate were used as precursor materials. The synthesized powders were characterized using x-ray diffraction pattern (XRD), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM), Raman spectroscopy as well as MTT assay and cell adhesion test. Disc diffusion method was used to investigate antibacterial activity of the samples. The results confirmed the substitution of Ca by Co ions in the HAp lattice. In addition, this substitution induced size reduction and morphology change in HAp particles. All cobalt substituted HAp powder samples displayed paramagnetic properties, as opposed to the diamagnetic behaviour observed in the pure HAp samples. In addition, these nanoparticles exhibited cell adhesion, biocompatibility and antibacterial activity against S.aureus bacteria

The aim of this study was to synthesize Ag-nanoclay composite by solid ion exchange, then characterize, and evaluate the antibacterial activity. This newly introduced ion exchange is a simple and low cost technique, which provides a quicker method. Without chemical treatment, nanoclay was subjected to an ion exchange process in media containing molten salt of silver at 300 and 400 °C and at different periods. Scanning electron microscopy showed that the flakes’ structure was opened by higher temperature and longer time. DRS graph revealed that Ag particles were successfully loaded, and that higher temperature and longer time increased the loading amount. Changes in basal reflection in XRD peak validated the presence of Ag. The Release test indicate that the materials do not present any risk for drinking water treatment since the leached metals were very small and in acceptable concentrations. The constant amount of release after four hours of sharp releasing. The antibacterial activity of the prepared composites was tested against gram-negative Escherichia coli and Staphylococcus aureus using the disc diffusion method. Presence of an inhibition zone clearly indicates the antibacterial effect of the composites. The results demonstrate that silver can be introduced onto nanoclay by single-step ion exchange.

Graphene oxide (GO) was synthesized by oxidation of graphite powder using a time-saving modification of Hummers’ method and its antibacterial activity was investigated. Different techniques were applied to characterize the synthesized GO. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were used to investigate the crystallinity, morphology, topography and thickness profile of the synthesized graphene oxide, respectively. Fourier-transform infrared spectroscopy (FT-IR) was carried out to investigate the chemical structure and purity of the synthesized sample. Optical properties were investigated by UV-Vis spectroscopy. The antibacterial activity of GO against Escherichia coli (E. coli) was evaluated by the Colony Forming Count (CFU) method. The Results confirmed that the sample had excellent antibacterial activity against Escherichia coli.

The external and interlamellar spaces of montmorilonite (MMT) were used as solid support for synthesis of CuO nanoparticles (NPs) at room temperature by the chemical reduction method. In this project, Copper Nitrate plus water (Cu(NO3)2. xH2O) and Sodium Hydroxide (NaOH) were used as Copper precursor and reducing agent respectively. Then, MMT/Cu2+ nanocomposites were stabilized with different range of the weight percent of Polyethylene glycol (PEG). The solids were characterized by X-Ray diffractometry (XRD), Scanning electron microscopy (SEM)‚ Transmission electron microscopy (TEM)‚ Fourier transform infrared (FT-IR) and UV-Visible spectroscopy. The antibacterial activities of different size of CuO NPs in MMT were investigated against Gram-positive‚ Staphylococcus aureus, Gram-negative bacteria and Escherichia coli‚ by the disk diffusion method using Muller-Hinton agar (MHA). These results were showed that smaller CuO NPs were found to have higher antibacterial activities. By this method we were able to obtain CuO NPs with different sizes and making them applicable to medical applications and can be used as effective growth inhibitors in different biological system.