Bioaccumulation and phytotoxicity of ZnO nanoparticles in soil-grown Brassica chinensis and potential risks

Author(s):  
Meimei Shen ◽  
Weitao Liu ◽  
Aurang Zeb ◽  
Jiapan Lian ◽  
Xiji Hu ◽  
...  

Abstract A pot-culture experiment was carried out to explore the phytotoxicity and accumulation of ZnO nanoparticles (ZnO NPs) in pakchoi (Brassica chinensis), as well as its potential risk. Zn was mainly accumulated in the shoots of pakchoi and showed the order of cell wall fraction > soluble fraction > organelles fraction. Endosomes were observed in roots cell by transmission electron microscope (TEM) and it is proving that endocytosis is a possible way for NPs to enter the cells. The results showed that higher concentration of ZnO NPs treatments resulted in an increase in the content of photosynthetic pigments and malondialdehyde (MDA), Catalase (CAT) and ascorbate peroxidase (APX) activity, while the activity of superoxide dismutase (SOD) and guaiacol peroxidase (G-POD) decreased significantly compared with the control. These changes suggest that the mechanism of ZnO NPs phytotoxicity may induce strongly oxidative stress and damage biomembrane. Generally, ZnO NPs had a similar impact on the growth and absorption of Zn in pakchoi with Zn2+. Simultaneously, the treatment of ZnO NPs affected the nutritional quality and food safety of pakchoi at high concentration.

2022 ◽  
Vol 306 ◽  
pp. 114454
Author(s):  
Meimei Shen ◽  
Weitao Liu ◽  
Aurang Zeb ◽  
Jiapan Lian ◽  
Jiani Wu ◽  
...  

Nano LIFE ◽  
2014 ◽  
Vol 04 (01) ◽  
pp. 1440003 ◽  
Author(s):  
Myisha Roberson ◽  
Vijaya Rangari ◽  
Shaik Jeelani ◽  
Temesgen Samuel ◽  
Clayton Yates

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.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3084
Author(s):  
Sajjad Mohsin I. Rayyif ◽  
Hamzah Basil Mohammed ◽  
Carmen Curuțiu ◽  
Alexandra Cătălina Bîrcă ◽  
Alexandru Mihai Grumezescu ◽  
...  

Zinc oxide (ZnO) nanoparticles (NPs) have been investigated for various skin therapies in recent years. These NPs can improve the healing and modulate inflammation in the wounds, but the mechanisms involved in such changes are yet to be known. In this study, we have designed a facile ZnO nano-coated dressing with improved antimicrobial efficiency against typical wound pathogens involved in biofilm and chronic infections. ZnO NPs were obtained by hydrothermal method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. Antibacterial and antibiofilm effects were evaluated against laboratory and clinical isolates of significant Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Staphylococcus aureus and Enterococcus faecalis) opportunistic pathogens, by quantitative methods. Our results have shown that the developed dressings have a high antibacterial efficiency after 6–24 h of contact when containing 0.6 and 0.9% ZnO NPs and this effect is similar against reference and clinical isolates. Moreover, biofilm development is significantly impaired for up to three days of contact, depending on the NPs load and microbial species. These results show that ZnO-coated dressings prevent biofilm development of main wound pathogens and represent efficient candidates for developing bioactive dressings to fight chronic wounds.


2021 ◽  
Vol 24 (12) ◽  
pp. 2147-2151
Author(s):  
Y.A. Dallatu ◽  
G.A. Shallangwa ◽  
S.N. Africa

The use of plant extracts has become an interesting ecofriendly method to synthesize and stabilize the different structures nanoparticles (NPs). This work investigated the effect of plant extract as a reducing and stabilizing agent on the growth and morphology of ZnO nanoparticles (ZnO-NPs). Green synthesis and growth of spherical ZnONPs was carried out by co-precipitation method using a Zinc acetate salt and various amounts of Azadirachta indica seed husk extract (20 ml and 40 ml). The synthesized ZnO-NPs were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM-EDX), and transmission electron microscopy (TEM). The FTIR analyses revealed the presence of Phenolic alcohol, amines and carboxylic acid groups and ZnO in synthesized NPs with more intense peaks at higher amount (40 ml) of A. indica extract. Also, structural morphology analyses using SEM revealed uniform spherical shaped particles with diameter from 25 to 60 nm (20 ml of extract) and 19 to 35 nm (40 ml of extract) for ZnO-NPs. The EDX spectral revealed that the required phase of Zn and O was present 69.54% (Zn) and 30.46% (O) at 20 ml of extract, also 73.71% (Zn), 26.26% (O) at 40 ml of extract respectively and confirmed high purity for the synthesized ZnO NPs. TEM revealed spherical shaped NPs with diameter ranging from 28 to 52 nm (20 ml of extract) and 8.2 to 11.9 nm (40 ml of extract) respectively, with a trend reduction in particle size of NPs at higher amount of A. indica seed extract (40 ml) and growth of more uniform particles with no agglomeration. The study showed successful growth of spherical ZnO-NPs with required properties at a higher amount of extract.


2020 ◽  
Vol 81 (6) ◽  
pp. 1296-1307
Author(s):  
R. Jeyachitra ◽  
S. Kalpana ◽  
T. S. Senthil ◽  
Misook Kang

Abstract Methylene blue (MB) dye is the most common harmful, toxic, and non-biodegradable effluent produced by the textile industries. The present study investigates the effect of zinc oxide (ZnO) nanoparticles (NPs) and Ag–Ni doped ZnO NPs on the performance of photocatalytic degradation of MB dye. Pure ZnO and Ag–Ni doped ZnO NPs are synthesized using the co-precipitation method. The crystalline nature and surface morphology of the synthesized pure ZnO and Ag–Ni doped ZnO NPs was characterized by powder X-ray diffraction, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM) analysis. The presence of spherical-like morphologies was confirmed from SEM and HRTEM analysis. The presence of Ni–O and Zn–O bands in the synthesized materials was found by Fourier transform infrared (FTIR) spectroscopy analysis. The MB dye was degraded under UV-light exposure in various pH conditions. The Ag (0.02%)–Ni doped ZnO NPs exhibits highest photocatalytic activity of 77% under pH 4.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1841 ◽  
Author(s):  
Guangyu Zhang ◽  
Yao Xiao ◽  
Jiawei Yan ◽  
Ningwei Xie ◽  
Rong Liu ◽  
...  

Herein, ZnO nanoparticles (NPs) were synthesized using zinc acetate and an amino hyperbranched polymer. The methods of transmission electron microscope (TEM) and X-ray Diffraction (XRD) were applied to the characterization of ZnO NPs. Polypropylene (PP)/ZnO fiber was prepared using 1–5 wt% ZnO NPs via melt spinning. The ultraviolet light (UV)-degradation behavior, antibacterial activity and mechanical properties of PP fibers were characterized. The PP fiber filled with ZnO NPs presents better mechanical properties and the resistance to UV light degradation. For the best effect, the contents of ZnO NPs were set 4 wt% in PP fiber. FTIR analysis shows significant photo-degradation of PP induced by UV irradiation and a remarkable reduction in the UV degradation of the fiber filled with ZnO NPs. It is also observed that the ZnO NPs-filled fiber has good antibacterial actives against Escherichia coli and staphylococcus aureus.


2016 ◽  
Vol 34 (4) ◽  
pp. 708-714 ◽  
Author(s):  
Yan Li ◽  
Fang-Xian Zhao ◽  
Xiao-Xue Lian

AbstractAu-modified ZnO (Au/ZnO) nanoparticles (NPs) synthesized using bamboo cellulose template and calcination process were characterized using X-ray diffraction, field-emission scanning electron microscopy, and transmission electron microscopy. The gas-sensing performance of Au/ZnO NPs based sensors was also examined. The results indicated that the Au/ZnO NPs exhibited enhanced gas-sensing performance compared with that of pure ZnO. The response of the Au/ZnO NPs to 100 ppm ethanol (50) at 240 °C was nearly 2.7 times higher than that to acetone (18.4) and approximately 12.5 times higher than that to benzene (4.1), carbon monoxide (1.6), hydrogen (1.6), and methane (1.8), respectively, which demonstrated their higher selectivity to ethanol versus other gases. This high response to ethanol could be attributed to the small size, Schottky barrier, and catalysis.


Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 336 ◽  
Author(s):  
Mohammad Azam Ansari ◽  
Mahadevamurthy Murali ◽  
Daruka Prasad ◽  
Mohammad A. Alzohairy ◽  
Ahmad Almatroudi ◽  
...  

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.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2489
Author(s):  
Ami Yoo ◽  
Mengshi Lin ◽  
Azlin Mustapha

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.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2072
Author(s):  
Maria Antonia Tănase ◽  
Maria Marinescu ◽  
Petruta Oancea ◽  
Adina Răducan ◽  
Catalin Ionut Mihaescu ◽  
...  

In the present work, the properties of ZnO nanoparticles obtained using an eco-friendly synthesis (biomediated methods in microwave irradiation) were studied. Saponaria officinalis extracts were used as both reducing and capping agents in the green nanochemistry synthesis of ZnO. Inorganic zinc oxide nanopowders were successfully prepared by a modified hydrothermal method and plant extract-mediated method. The influence of microwave irradiation was studied in both cases. The size, composition, crystallinity and morphology of inorganic nanoparticles (NPs) were investigated using dynamic light scattering (DLS), powder X-ray diffraction (XRD), SEM-EDX microscopy. Tunings of the nanochemistry reaction conditions (Zn precursor, structuring agent), ZnO NPs with various shapes were obtained, from quasi-spherical to flower-like. The optical properties and photocatalytic activity (degradation of methylene blue as model compound) were also investigated. ZnO nanopowders’ antibacterial activity was tested against Gram-positive and Gram-negative bacterial strains to evidence the influence of the vegetal extract-mediated synthesis on the biological activity.


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