scholarly journals Structural, Morphological and Antimicrobial Study of ZnO/Ag Nanoparticles

2020 ◽  
Vol 13 (4) ◽  
pp. 1645-1652
Author(s):  
Richa Sharma ◽  
Suresh Kumar ◽  
Prem Singh ◽  
Shikha Kapila

Metal oxide nanoparticles gain attention in the field of biomedical applications because of their unique physico-chemical properties and emerging out as an alternative to antibiotics. The major cause of most of the human diseases is the bacterial infection. However, antibiotics used in the cure show other complications to human health. Therefore, the purpose of the present work is to investigate the antibacterial properties of ZnO/Ag nanoparticles on the test bacterial strains, Escherichia coli (E. coli). ZnO/Ag nanoparticles are synthesized using surfactant mediated route in a single step and double step procedure. Here, CTAB and hydrazine hydrate used as a surfactant and reducing agents respectively. The synthesized nanoparticles are characterized by x-ray diffraction, scanning electron microscopy and energy dispersive x-ray spectroscopy for structure, morphology and compositional properties. The antibacterial activities of these nanoparticles are also studied using the agar-well diffusion technique. The result analysis shows that synthesized nanopaticles are spherical in shape, having particles of the size 6 nm and 13 nm in the desired elemental composition. ZnO/Ag nanoparticles possessed a strong antibacterial effect against E. coli. This study signifies that ZnO/Ag metal oxide nanoparticles exhibit stronger antimicrobial activity against pathogen bacteria E. coli which may works effectively on the antibacterial and antifungal infections.

2021 ◽  
Vol 12 (5) ◽  
pp. 6557-6579

The introduction of inorganic and organic pollutants into water bodies has become a serious issue globally. The waste streams released from the textile, plastic, leather, paper, pharmaceutical, and food industries introduce different natural and synthetic dyes into the aquatic system. Nanomaterials play a significant role in the photocatalytic degradation of dyes present in wastewater. Inorganic metal oxide nanoparticles have many improved physical and chemical properties and attracted much attention in photocatalytic activities. Dyes have been released in our aquatic bodies due to many anthropogenic activities and caused life-threatening problems. Various conventional methods were reported to remove dyes from water and wastewater; the photocatalytic method is one of the efficient and cost-effective. The present review article includes detailed information on photocatalysis, the potential of metal oxide and their composite materials as photocatalysts in the degradation of toxic dyes, and some common synthetic and characterization methods used for metal oxide-based nanoparticles.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexandra Guerreiro ◽  
Nicholas Chatterton ◽  
Eleanor M. Crabb ◽  
Jon P. Golding

Abstract Background A wide range of nanoparticles (NPs), composed of different elements and their compounds, are being developed by several groups as possible radiosensitisers, with some already in clinical trials. However, no systematic experimental survey of the clinical X-ray radiosensitising potential of different element nanoparticles has been made. Here, we directly compare the irradiation-induced (10 Gy of 6-MV X-ray photon) production of hydroxyl radicals, superoxide anion radicals and singlet oxygen in aqueous solutions of the following metal oxide nanoparticles: Al2O3, SiO2, Sc2O3, TiO2, V2O5, Cr2O3, MnO2, Fe3O4, CoO, NiO, CuO, ZnO, ZrO2, MoO3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Tb4O7, Dy2O3, Er2O3 and HfO2. We also examine DNA damage due to these NPs in unirradiated and irradiated conditions. Results Without any X-rays, several NPs produced more radicals than water alone. Thus, V2O5 NPs produced around 5-times more hydroxyl radicals and superoxide radicals. MnO2 NPs produced around 10-times more superoxide anions and Tb4O7 produced around 3-times more singlet oxygen. Lanthanides produce fewer hydroxyl radicals than water. Following irradiation, V2O5 NPs produced nearly 10-times more hydroxyl radicals than water. Changes in radical concentrations were determined by subtracting unirradiated values from irradiated values. These were then compared with irradiation-induced changes in water only. Irradiation-specific increases in hydroxyl radical were seen with most NPs, but these were only significantly above the values of water for V2O5, while the Lanthanides showed irradiation-specific decreases in hydroxyl radical, compared to water. Only TiO2 showed a trend of irradiation-specific increase in superoxides, while V2O5, MnO2, CoO, CuO, MoO3 and Tb4O7 all demonstrated significant irradiation-specific decreases in superoxide, compared to water. No irradiation-specific increases in singlet oxygen were seen, but V2O5, NiO, CuO, MoO3 and the lanthanides demonstrated irradiation-specific decreases in singlet oxygen, compared to water. MoO3 and CuO produced DNA damage in the absence of radiation, while the highest irradiation-specific DNA damage was observed with CuO. In contrast, MnO2, Fe3O4 and CoO were slightly protective against irradiation-induced DNA damage. Conclusions Beyond identifying promising metal oxide NP radiosensitisers and radioprotectors, our broad comparisons reveal unexpected differences that suggest the surface chemistry of NP radiosensitisers is an important criterion for their success.


2014 ◽  
Vol 86 (5) ◽  
pp. 785-800 ◽  
Author(s):  
Pengyu Wang ◽  
Kazuya Kobiro

AbstractA simple, rapid (10 min), one-pot, single-step method for the preparation of solid and hollow spherical porous TiO2 nanoparticles with large surface areas (100–211 m2/g) was developed in supercritical alcohols using carboxylic acids as organic additives. The shell thickness of the hollow TiO2 nanoparticles (20–280 nm) was controlled by adjusting the heating rate (2.0–10.0 °C/min). The preparation of different spherical porous metal oxide nanoparticles, including CeO2, SiO2, TiO2, ZrO2, and ZnO, demonstrated the versatility of the synthetic approach. In addition, several rare earth-doped spherical mesoporous metal oxide nanoparticles, including CeO2:Er, CeO2:Er,Yb, ZrO2:Er, and TiO2:Er, which exhibit energy upconversion emission, were successfully prepared using this one-pot, single-step, supercritical methanol method. The obtained spherical mesoporous CeO2:Er and CeO2:Er,Yb nanoparticles emit green light upon excitation, even when irradiated with a low-power IR laser (980 nm, 10 mW) without calcination. Several other (metal) elements were also easily doped into spherical, mesoporous TiO2 nanoparticles, such as Eu, Ce, Yb, Fe, and N, using a similar procedure. Furthermore, the spherical mesoporous TiO2 nanoparticles were successfully applied as a new material for the transport of DNA via biolistic bombardment.


RSC Advances ◽  
2015 ◽  
Vol 5 (59) ◽  
pp. 48094-48103 ◽  
Author(s):  
D. Liu ◽  
A. M. Pourrahimi ◽  
L. K. H. Pallon ◽  
R. L. Andersson ◽  
M. S. Hedenqvist ◽  
...  

A facile single-step method for obtaining 2–3 nm thick silsesquioxane coatings on metal oxide nanoparticles using different carbon-functional silane precursors is presented.


2020 ◽  
Vol 14 (3) ◽  
pp. 1999-2008
Author(s):  
H. Syed Jahangir ◽  
T. Tamil Kumar ◽  
M. Mary Concelia ◽  
R. Alamelu

Green synthesis nanoparticles were considered as an alternative effective resource instead of chemically engineered metal oxide nanoparticles. Using leaf extracts for green synthesis, essential for the reduction and oxidation process of the metals. Phyllanthus niruri (L.) and Aristolochia indica (L.) leaf extracts were used to synthesize yellowish brown coloured silver (Ag) and white coloured zinc oxide (ZnO) nanoparticles. Synthesized green nanoparticles characterized by different spectroscopic analysis (XRD, XPS, FTIR, PL) and TEM. Characterization results confirmed the particles morphology, size, structure and also their optical and photonic properties. Three different concentrations of Ag and ZnO NPs were analysed against three (gram positive) and five (gram negative) bacteria. Increased levels of green synthesized Ag and ZnO NPs showed increased zone of inhibition than amoxicillin (positive control). Our study proved that the green synthesized Ag and ZnO NPs showed similar unique physical and chemical properties with metal oxide nanoparticles but less toxic while their discharge into the ecosystem.


Author(s):  
Mahbooubeh Mirhosseini ◽  
Roghayeh Dehestani

Background: The spread of pathogenic microorganisms in food and beverage and their resistance to antibiotics have raised major concerns for public health. The aim of this study was to investigate the antimicrobial activity of various metal oxide nanoparticles (NPs) including zinc oxide (ZnO), magnesium oxide (MgO), and iron oxide (Fe2O3) NPs against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Furthermore, the antimicrobial activity of these NPs in milk was studied along with mild heat. Methods: In this experimental study, the antibacterial activity of ZnO, MgO, and Fe2O3 NPs were initially evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Later, the antimicrobial effect of these NPs was investigated in milk along with mild heating. To determine the morphological changes in S. aureus and E. coli, electron microscopy scanning was applied before and after the antimicrobial treatments. Results: The MBC and MIC values presented by Fe2O3, ZnO, and MgO NPs against pathogenic bacteria showed that MgO NPs were the most potent substances for inhibiting the growth of S. aureus and E. coli. The results also indicated that use of these NPs had synergistic effects in combination with the heating treatment. Electron microscopy scanning also revealed that treatment with MgO NPs could distort and impair the cell wall of the pathogenic bacteria, leading to the leakage of intracellular components and bacterial death. Conclusion: The results suggest that MgO, ZnO, and Fe2O3 NPs can be applied for industrial food processing as effective antimicrobial compounds to decrease the temperature required for pasteurizing milk.


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