scholarly journals Antibacterial Activity and Morphological Characterization of Synthesis Graphene Oxide Nanosheets by Simplified Hummer’s Method

2018 ◽  
Vol 15 (3) ◽  
pp. 627-633 ◽  
Author(s):  
Russel R. Ghanim ◽  
M. R. Mohammad ◽  
Adi M. Abdul Hussien

Graphene oxide (GO) nanosheets were prepared by a novel simplified Hummer's method. The morphological and cross section images of GO have been tested with field emission-scanning electron microscope (FE-SEM). The antibacterial activity of GO nansheets against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were investigated as a model for Gram-negative bacteria and Gram-positive bacteria respectively. Bacteriological tests were performed by agar well diffusion assay with different concentrations of GO nanosheets and the bacterial morphological change of two bacterial species has been studied by scanning electron microscope (SEM) before and after treated with GO nanosheets. These sheets have been approved to be an effective bactericide. The antibacterial activity of the nanosheets dispersion was measured by agar well diffusion method. Scanning electron microscopy (SEM) was used to investigate the biocidal action of this nanoscale material. The nanosheets of GO have shown a high antibacterial activity against Gram-positive bacteria. The results of the present work offer a novel assay to prepare GO nanosheets were it could be used as novel antibacterial agent in future for different areas of biomedical and pharmaceutical sciences, like biosensing, antibiotics, imaging, and drug delivery.

Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad

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.


2015 ◽  
Vol 1109 ◽  
pp. 381-384
Author(s):  
M. Safwan Azmi ◽  
Sharipah Nadzirah ◽  
Uda Hashim

The purpose of this paper is to study the morphological characterization of aluminum interdigitated electrodes (IDE) of different gap sizes on silicon substrate. The electrodes were fabricated using standard photolithography process and were done so with sizes of 12 μm, 10 μm and 7 μm. The electrodes were morphologically characterized using scanning electron microscope (SEM) and high-powered microscope (HPM).Keywords: morphological, interdigitated electrodes, aluminum


2012 ◽  
Vol 7 (5) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Alexis Peña ◽  
Luis Rojas ◽  
Rosa Aparicio ◽  
Libia Alarcón ◽  
José Gregorio Baptista ◽  
...  

The essential oil of the leaves of Espeletia nana Cuatrec, obtained by hydrodistillation, was analyzed by GC-MS, which allowed the identification of 24 components, which made up 99.9% of the oil. The most abundant compounds were α-pinene (38.1%), β-pinene (17.2%), myrcene (15.0%), spathulenol (4.2%), bicyclogermacrene (4.0%), α-zingiberene (4.0%), and γhimachalene (3.7%). Antibacterial activity was tested against Gram-positive and Gram-negative bacteria using the agar disk diffusion method. Activity was observed only against Gram-positive bacteria. MIC values were determined for Staphylococcus aureus ATCC 25923(200 μg/mL) and Enterococcus faecalis ATCC 29212 (600 μg/mL).


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
A. Hedayat ◽  
J. Szpunar ◽  
N. A. P. Kiran Kumar ◽  
R. Peace ◽  
H. Elmoselhi ◽  
...  

Background. Morphological characterization of hemodialysis membranes is necessary to improve pore design.Aim. To delineate membrane pore structure of a high flux filter, Polyflux 210H.Methods. We used a Joel JSM-6010LV scanning electron microscope (SEM) and a SU6600 Hitachi field emission scanning electron microscope (FESEM) to characterize the pore and fiber morphology. The maximal diameters of selected uremic toxins were calculated using the macromolecular modeling Crystallographic Object-Oriented Toolkit (COOT) software.Results. The mean pore densities on the outermost and innermost surfaces of the membrane were 36.81% and 5.45%, respectively. The membrane exhibited a tortuous structure with poor connection between the inner and outer pores. The aperture’s width in the inner surface ranged between 34 and 45 nm, which is 8.76–11.60 times larger than the estimated maximum diameter ofβ2-microglobulin (3.88 nm).Conclusion. The results suggest that the diameter size of inner pore apertures is not a limiting factor to middle molecules clearance, the extremely diminished density is. Increasing inner pore density and improving channel structure are strategies to improve clearance of middle molecules.


2010 ◽  
Vol 16 (S2) ◽  
pp. 50-51
Author(s):  
K Teramoto ◽  
H Nishiyama ◽  
Y Maruyama ◽  
Y Konyuuba ◽  
Y Abe ◽  
...  

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.


2018 ◽  
Vol 29 ◽  
pp. 70-77 ◽  
Author(s):  
Anjana Devkota ◽  
Ritu Kumari Das

Antibacterial activities of Xanthium strumarium L. (Asteraceae) was carried out in laboratory. Distilled water and methanol extracts of the leaves of plant was prepared. The antibacterial activity was studied against six pathogenic bacteria, three gram negative: Klebsiella pneumoniae (ATCC 15380), Proteus mirabilis (ATCC 49132), Escherichia coli (ATCC 25922) and three gram positive: Bacillus subtilis (ATCC 6633), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25932) at different concentrations (50 mg/ml, 100 mg/ml, 150 mg/ml, 200 mg/ ml, 250 mg/ml) of leaf extracts of X. strumurium. The phytochemical screening depicted the presence of terpenoids, saponins, flavonoids, tannins and alkaloids. The antibacterial activity of extracts was determined by disc diffusion method and zone of inhibition (ZOI) was measured. Gram negative bacteria was found more resistant than gram positive bacteria. The most susceptible bacterium was S. aureus while the most resistant bacterium was E. coli. Methanolic extract was found more effective than distilled water. These findings suggest that extracts obtained from leaves of X. strumurium possess biobactericidal potential, which can suitably be exploited for making antibacterial drugs.J. Nat. Hist. Mus. Vol. 29, 2015, Page: 70-77


2020 ◽  
Vol 10 (5) ◽  
pp. 274-292
Author(s):  
Rohit Kumar ◽  
Sushil Kumar ◽  
Mohammad Asif Khan

Recently a series of Schiff bases of diphenylamine derivatives have been synthesized and evaluated in vitro for their antibacterial activity against pathogenic both Gram-positive bacteria B. subtitles and Gram-negative bacteria E. coli using ciprofloxacin as standard drug at conc. of 50 μg/ml and 100 μg/ml. Literature review revels that chalcones possesses various biological activities like antimicrobial, antiviral, anti-inflammatory, anticancer and sedative etc. Therefore the present study was designed on synthesis and pharmacological evaluation of 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides. Target compound was synthesized by reaction of chloroacetylchloride with diphenylamine to afford 2-chloro-N, N-diphenylacetamide which further by reaction with substituted Chalcones and characterized following recrystallization and evaluated for anti-microbial potential through cup-diffusion method. In results, the target compounds were tested for activity against B. Subtilis, E.Coli and C. albicans. The chalcones having the lipophilic 4-chloro group (RKCT2) showed the greatest antimicrobial activity (zone of inhibition 20 & 22 mm against. B. subtilis, E. Coli, C. Albicans respectively. It suggests further researchers to go through anti-microbial evaluations against a more varieties of bacteria and fungi. Keywords: Schiff bases of diphenylamine derivatives, antibacterial activity, Gram-positive bacteria, 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides


2011 ◽  
pp. 263-269 ◽  
Author(s):  
Aleksandra Velicanski ◽  
Dragoljub Cvetkovic ◽  
Sinisa Markov ◽  
Jelena Vulic ◽  
Sonja Djilas

Antibacterial activity of Beta vulgaris L. (beetroot) pomace extract (concentration 100 mg/ml) was tested against five Gram positive and seven Gram negative bacterial strains (reference cultures and natural isolates). Disc diffusion method with 15 ?l of extract and agar-well diffusion method with 50 and 100 ?l were used. Antibiotic (cefotaxime/clavulanic acid) was used as a control sample. The tested extract showed the highest activity against Staphylococcus aureus and Bacillus cereus, where clear zones (without growth) appeared. There was no any activity against other tested Gram-positive bacteria, except for Staphylococcus epidermidis, with a small zone of reduced growth. Growth of all tested Gram-negative bacteria was inhibited usually with 100 ?l of extract. The most susceptible were Citrobacter freundii and Salmonella typhymurium. The tested antibiotic gave clear, usually large zones for all tested strains except for Staphylococcus cohni spp. cohni, where only a zone of reduced growth appeared.


2021 ◽  
Vol 880 (1) ◽  
pp. 012047
Author(s):  
Eman Mubdir Nayf ◽  
Hamzah Abdulrhaman Salman

Abstract Myrtus communis is an evergreen plant that can survive stressful environments and high-temperature seasons. Treatment using green plants was the most trended in recent years. The present study aimed to evaluate the antibacterial effects of Myrtus communis leaves against bacteria isolated from periodontitis. Fifty samples were collected from periodontitis subjects in both genders (female 32 % and male 68 %). The isolates were diagnosed by morphological characterization and biochemical tests. M. communis leaves were identified, collected, and prepared for extraction. The plant leaves were extracted using distilled water. The antibacterial susceptibility testing was performed by the well diffusion method. Antibiotics susceptibility patterns were executed using the disc diffusion method. All the isolates belonged to gram-positive bacteria. Among the isolated bacteria, 20, 18, and 12 were Lactobacillus spp., Streptococcus spp., and Staphylococcus aureus, respectively. The antibacterial susceptibility testing of M. communis extract showed a potential zone of inhibition against all the tested bacteria. Of the different concentrations, 30 mg/ml showed the highest zone of inhibition, 18.2 mm, 19.50 mm, and 30.66 mm against Streptococcus spp., Staphylococcus spp., and Lactobacillus spp. Among the tested antibiotics, ciprofloxacin and chloramphenicol exhibited the highest zone of inhibition against the tested bacteria. The aquatic extract of M. communis leaves was found to be effective against gram-positive bacteria. Further studies are warranted to investigate the active bio-compounds.


INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (06) ◽  
pp. 30-35
Author(s):  
Naveen K. Kottakki ◽  
◽  
Amperayani K. Rao ◽  

In the current study, a series of piperine – piperazine analogues (5a to 5f) were designed and synthesized. The piperine was isolated from pepper and used for the conjugation with heterocyclic moiety for better biological activity. The piperazine heterocyclic was chosen for conjugation with piperine. The newly synthesized structures were determined by IR, 1H NMR and 13C NMR spectral data. The compounds were examined for their anti‐microbial activity against gram-positive (Bacillus subtilis) and gram-negative (Vibrio cholerae) bacteria using the agar well diffusion method. The newly synthesized compounds exhibited capable activities against V. cholerae and B. subtilis and it showed minimum inhibitory concentration. Among all the synthesized compounds, 5f has the highest activity (26 mm) against gram-positive bacteria and (29mm) against gram-negative bacteria. The remaining compounds showed appreciable antibacterial activity. The enhanced activity of the synthesized compounds may be due to the presence of conjugated amide linkage with the natural product piperine and piperazine heterocyclic molecule. The substituents present on the aromatic (nitro-substituted) ring also influenced the activity of the compound.


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