scholarly journals Zinc Oxide and Silver Nanoparticle Effects on Intestinal Bacteria

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2489
Author(s):  
Ami Yoo ◽  
Mengshi Lin ◽  
Azlin Mustapha
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Morphological Changes ◽  
Intestinal Bacteria ◽  
Bacterial Cells ◽  
Ag Nps ◽  
Zno Nps ◽  
Bifidobacterium Animalis ◽  
Transmission Electron

The application of nanoparticles (NPs) for food safety is increasingly being explored. Zinc oxide (ZnO) and silver (Ag) NPs are inorganic chemicals with antimicrobial and bioactive characteristics and have been widely used in the food industry. However, not much is known about the behavior of these NPs upon ingestion and whether they inhibit natural gut microflora. The objective of this study was to investigate the effects of ZnO and Ag NPs on the intestinal bacteria, namely Escherichia coli, Lactobacillus acidophilus, and Bifidobacterium animalis. Cells were inoculated into tryptic soy broth or Lactobacilli MRS broth containing 1% of NP-free solution, 0, 12, 16, 20 mM of ZnO NPs or 0, 1.8, 2.7, 4.6 mM Ag NPs, and incubated at 37 °C for 24 h. The presence and characterization of the NPs on bacterial cells were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Membrane leakage and cell viability were assessed using a UV-visible spectrophotometer and confocal electron microscope, respectively. Numbers of treated cells were within 1 log CFU/mL less than those of the controls for up to 12 h of incubation. Cellular morphological changes were observed, but many cells remained in normal shapes. Only a small amount of internal cellular contents was leaked due to the NP treatments, and more live than dead cells were observed after exposure to the NPs. Based on these results, we conclude that ZnO and Ag NPs have mild inhibitory effects on intestinal bacteria.

Growth and Characterization of Misostructural Zinc Oxide Tubes

2005 ◽  
Vol 23 ◽  
pp. 293-296
Author(s):  
X.W. Sun ◽  
C.X. Xu ◽  
B.J. Chen ◽  
Y. Yang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Zinc Oxide ◽  
Growth Process ◽  
Hexagonal Structure ◽  
Metallic Zinc ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Zinc oxide (ZnO) microtube has been fabricated by heating the mixture of ZnO and graphite powders in the atmosphere. The ZnO microtubes showed perfect hexagonal profiles with bell-mouth or normal hexagonal tops. Both X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM) demonstrated that the product was composed of ZnO with typical hexagonal structure grown predominantly along (002) direction. The growth process was interpreted by means of vaporliquid-solid mechanism combining with the evaporation of metallic zinc.

scholarly journals Microwave-assisted synthesis and characterization of microstar shaped zinc oxide

Quimica Hoy ◽  
2012 ◽  
Vol 2 (3) ◽  
pp. 3
Author(s):  
Idalia Gómez ◽  
Miguel José Yucam´án ◽  
Flor Palomar
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Microwave Assisted Synthesis ◽  
Stoichiometric Ratio ◽  
Crystalline Materials ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Synthesis Procedure ◽  
Post Synthesis

A microwave-assisted solution-phase approach has been applied for the synthesis ofzinc oxide microstructures. Toe synthesis procedure was carried out by using the reagents: Zinc ni trate and Methenamine, at stoichiometric ratio. Analysis by means ofX-ray Diffraction (XRD) shows a crystalline phase in hexagonal wurtzite arrangement for ZnO. The presence ofmicrostar shaped zinc oxide (2-3μm) with nanorods,f50nm) arranged has been confirmed from High Resolution Scanning Electron Microscopy (HRSEM). The formation of nanorods was confirmed by Transmission Electron Microscopy. In Raman spectroscopy a red shift was detected in the microstructures compared with ZnO bulk. High crystalline materials without additional post-synthesis treatrnent were found.

Synthesis and Characterization Silver, Zinc Oxide and Hybrid Silver/Zinc Oxide Nanoparticles for Antimicrobial Applications

Nano LIFE ◽  
2014 ◽  
Vol 04 (01) ◽  
pp. 1440003 ◽  
Author(s):  
Myisha Roberson ◽  
Vijaya Rangari ◽  
Shaik Jeelani ◽  
Temesgen Samuel ◽  
Clayton Yates
Keyword(s):  
Zinc Oxide ◽  
Zno Nanoparticles ◽  
Biomedical Application ◽  
Fungal Growth ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Zno Nps ◽  
E Coli ◽  
Transmission Electron ◽  
20 Nm

Silver ( Ag ) and zinc oxide ( ZnO ) are well known for both antimicrobial and pro-healing properties. Here, we present a novel method to synthesize Ag and ZnO nanoparticles (NPs), as well as hybrid Ag / ZnO NPs using a custom, temperature controlled microwave assisted technique. Microwave synthesis has been shown not only to enhance the rate of chemical reactions, but also in some cases to give higher product yields over thermal heating. The as-synthesized NPs were characterized by X-ray diffraction (XRD) to study the crystalline structure, composition and purity. Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) was used to study particle size, shape, composition and morphology. These results indicated that the as-prepared Ag NPs are spherical in shape and ~ 20 nm in sizes. The ZnO NPs are typically rod shaped and the particle sizes are ~ 20 nm in width and 100 nm in length. These NPs were tested for antibacterial and/or antifungal properties using disc diffusion assays. Results show microwave synthesized NPs inhibit growth of S. aureus, E. coli and C. albicans at 50 μ g/mL treatment concentration. Ag NPs were most effective in inhibiting bacterial and fungal growth at the concentrations tested followed by hybrid Ag / ZnO and ZnO nanoparticles. These results also suggest that the hybridization of ZnO to Ag NPs may reduce the toxicity of Ag NPs. Further studies are needed to understand the functional interaction between the two types of NPs and to improve their ability for biological or biomedical application.

Size-Dependent Biological Activities of Fluorescent Organosilane-Modified Zinc Oxide Nanoparticles

2020 ◽  
Vol 16 (2) ◽  
pp. 137-152
Author(s):  
Mariana Buşilă ◽  
Aurel Tăbăcaru ◽  
Viorica Muşsat ◽  
Bogdan Ştefan Vasile ◽  
Ionela Andreea Neaşu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Zinc Oxide ◽  
Cancer Cells ◽  
Zinc Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Cytotoxic Activities ◽  
Zno Nps ◽  
Size Dependent ◽  
Transmission Electron

Surface modification of zinc oxide nanoparticles (ZnO NPs) is a strategy to tune their biocompatibility. Herein we report on the synthesis of a series of fluorescent ZnO NPs modified with 2–10% (3-glycidyloxypropyl)trimethoxysilane (GPTMS) to investigate the fluorescence properties and to explore their applications in microbiology and biomedicine. The obtained ZnO NPs were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR). Size reduction occurred from ca. 13 nm in unmodified ZnO to 3–4 nm in silane-modified samples and fluorescence spectra showed size-dependent variation of the photoemission bands' intensity. The antibacterial and cytotoxic activities were investigated on Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria, and in ovarian (A2780) and prostate (PC3) cancer cells by tetrazolium/formazan-based methods. The antibacterial effect was higher for E. coli than S. aureus, while the cytotoxic activity was similar for both cancer cells and varied with the particle size. Cell death by apoptosis, and/or necrosis versus autophagy, were explored by flow cytometry using an Annexin V based-method and transmission electron microscopy (TEM). The main mechanism of ZnO NPs toxicity may involve the generation of reactive oxygen species (ROS) and the induction of apoptosis or autophagy. This work revealed the potential utility of GPTMS-modified ZnO NPs in the treatment of bacterial infection and cancer.

scholarly journals Effect of Zinc Oxide nanoparticals preparation from Zinc Sulphate (ZnSo4) against gram negative or gram positive microorganisms in vitro

2018 ◽  
Vol 42 (1) ◽  
pp. 18-22
Author(s):  
Khitam S. S
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Zinc Oxide ◽  
Morphological Changes ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
X Ray ◽  
Microscopy Images ◽  
Scanning Electron

     This research aims to prepare ZnO NPs by using chemical bath deposition way from ZnSO4 and NaOH as starting materials. It was examined by X-ray diffraction, Scanning Electron Microscopy, Zeta potential and Fourier Transformation Infrared. Scanning Electron Microscopy images showed various morphological changes of ZnO nanoparticles obtained by the above method and the different magnification Scanning Electron Microscopy images of the nanoparticle and confirms that the Nano flowers are grown with well-defined morphology and diameters varying between 60-110 nm. The effect of Zinc oxide nanoparticles against bacteria staphylococcus aureus, E.coli and Pseudomous aeruginosa showed the ability of this substance to inhibit the growth of all types of bacteria in different concentrations. The percentage of survival bacteria was (2, 3.7 and 6%) for E.coli bacteria and (1, 1.5 and 5 %) for Pseudomous aeruginosa bacteria, while the percentage was (0.8, 1 and 1.5 %) for staphylococcus aurous respectively for all concentration.

scholarly journals Cinnamomum verum Bark Extract Mediated Green Synthesis of ZnO Nanoparticles and Their Antibacterial Potentiality

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 336 ◽  
Author(s):  
Mohammad Azam Ansari ◽  
Mahadevamurthy Murali ◽  
Daruka Prasad ◽  
Mohammad A. Alzohairy ◽  
Ahmad Almatroudi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Green Synthesis ◽  
Zno Nanoparticles ◽  
Advanced Characterization ◽  
Wave Number ◽  
Bark Extract ◽  
Zno Nps ◽  
Sem Images ◽  
Transmission Electron

Cinnamomum verum plant extract mediated propellant chemistry route was used for the green synthesis of zinc oxide nanoparticles. Prepared samples were confirmed for their nano regime using advanced characterization techniques such as powder X-ray diffraction and microscopic techniques such as scanning electron microscopy and transmission electron microscopy. The energy band gap of the green synthesized zinc oxide (ZnO)-nanoparticles (NPs) were found between 3.25–3.28 eV. Fourier transmission infrared spectroscopy shows the presence of Zn-O bond within the wave number of 500 cm−1. SEM images show the specific agglomeration of particles which was also confirmed by TEM studies. The green synthesized ZnO-NPs inhibited the growth of Escherichia coli and Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 125 µg mL−1 and 62.5 µg mL−1, respectively. The results indicate the prepared ZnO-NPs can be used as a potential antimicrobial agent against harmful pathogens.

scholarly journals Synthesis, Characterization and Ammonia Sensing Studies on Novel Polypyrrole/Zinc Oxide/SWCNT Nanocomposite

2020 ◽  
Vol 32 (8) ◽  
pp. 1961-1966
Author(s):  
Ahmad Husain ◽  
Mohd Urooj Shariq ◽  
Sharique Ahmad ◽  
Anees Ahmad ◽  
Faiz Mohammad
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
Ammonia Sensing ◽  
Transmission Electron ◽  
Ft Ir ◽  
Very High ◽  
Ft Ir Spectroscopy

Herein, the synthesis and characterization of a novel polypyrrole (PPy)/zinc oxide (ZnO)/SWCNT nanocomposite together with pristine polypyrrole is reported. These as-prepared materials have been characterized by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) techniques. The PPy/ ZnO/SWCNT nanocomposite is used as a pellet-shaped ammonia sensor. The sensing response is calculated in terms of variation in the DC electrical conductivity at different concentration of ammonia ranging from 50 ppm to 2000 ppm. The sensing response of the sensor is determined at 2000, 1000, 500, 400, 300, 200, 100 and 50 ppm and found to be 76.3, 60.5, 54.8, 52.6, 50.2, 48.5, 40.5 and 36.6%, respectively The sensor displays excellent reversibility along with very high selectivity and stability. Finally, a sensing mechanism is also proposed involving polarons (charge carriers) of polypyrrole and lone pairs of electrons of ammonia molecules.

Synergistic Antibacterial Activity of Nanohybrid Materials ZnO–Ag and ZnO–Au: Synthesis, Characterization, and Comparative Analysis of Undoped and Doped ZnO Nanoparticles

2015 ◽  
Vol 68 (2) ◽  
pp. 288 ◽  
Author(s):  
Adriana Berenice Pérez Jiménez ◽  
Carlos Alberto Huerta Aguilar ◽  
Jorge Manuel Vázquez Ramos ◽  
Pandiyan Thangarasu
Keyword(s):  
Electron Microscopy ◽  
Zno Nanoparticles ◽  
Antibacterial Properties ◽  
Growth Control ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Ag Nps ◽  
Zno Nps ◽  
Au Nps ◽  
X Ray

ZnO nanoparticles (NPs) were prepared using the hydrothermal method, and then doped with Ag or Au NPs, yielding ZnO NPs, ZnO–Ag NPs, and ZnO–Au NPs, which were characterized by transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. The synthesized nanomaterials were analyzed for their antibacterial properties against bacterial strains (Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Salmonella typhi) by qualitative and quantitative assays. Minimal inhibitory concentration (MIC) results show that growth control is more effective for Gram-positive bacteria than for Gram-negative bacteria. Although ZnO NPs and Ag NPs are antibacterial agents, the lowest bacterial growth was observed for ZnO–Ag NPs, showing that the doped Ag NPs greatly facilitate the interaction between the microbial cells and the NP surface. Though the same antibacterial effect was expected for ZnO–Au NPs, the inhibition activity was very close to that of ZnO NPs. The order of bacterial cell growth inhibition was ZnO–Ag NPs >> ZnO–Au NPs ~ ZnO NPs >> ZnO powder. We also analyzed the morphology of bacterial cells treated with NPs by scanning electron microscopy.

scholarly journals Microscopy and Spectroscopy Characterization of Carbon Nanotubes Grown at Different Temperatures Using Cyclohexanol as Carbon Source

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Elsa G. Ordoñez Casanova ◽  
Héctor A. Trejo Mandujano ◽  
Manuel Román Aguirre
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Source ◽  
Morphological Changes ◽  
Spray Pyrolysis Technique ◽  
Product Yield ◽  
Structural Morphology ◽  
Transmission Electron ◽  
Different Temperatures

We present the structural and spectroscopy characterization of carbon nanotubes (CNTs) grown by the spray pyrolysis technique, using ferrocene as catalyzer and cyclohexanol as the carbon source, and synthetized in a temperature range of 750 to 1000°C. The structural morphology was observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The spectroscopy response was obtained by UV-Vis and Raman spectroscopy. We observed morphological changes and found that the product yield seems to increase with temperature. The optical characterization corroborated the presence of n – π∗ transitions and Van Hove singularities as result of possible electrical conductivity changes.

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