Inhibitory Effect of Flower-Shaped Zinc Oxide Nanostructures on the Growth and Aflatoxin Production of a Highly Toxigenic Strain of Aspergillus flavus Link

Flower-shaped zinc oxide (ZnO) nanostructures were prepared via a simple aqueous precipitation strategy at room temperature. The as-grown nanostructures were characterized by UV–vis spectroscopy, UV–vis diffuse reflectance spectroscopy (DRS), spectrofluorometry, Fourier transform infrared (FTIR) spectroscopy with attenuated total reflection (ATR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). The antifungal and anti-aflatoxigenic activities of the ZnO nanostructures were further investigated using a highly toxigenic strain of Aspergillus flavus Link under in vitro and in situ conditions. The results showed that the A. flavus isolate was inhibited to various extents by different concentrations of ZnO nanostructures, but the best inhibitions occurred at 1.25, 2.5, and 5 mM in the culture media. At these concentrations, suppression of aflatoxin biosynthesis (99.7%) was also observed. Moreover, a reasonable reduction in the aflatoxin content (69%) was observed in maize grains treated with the lowest ZnO concentration that exhibited the strongest inhibitory activity in the liquid media. SEM micrographs clearly indicate multiple degenerative alterations in fungal morphology after treatment with ZnO such as damage of the tubular filaments, loss of hyphae shape, as well as hyphae rupture. These results suggest that flower-shaped ZnO nanostructures exhibit strong antifungal and anti-aflatoxigenic activity with potential applications in the agro-food system.

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Optical Characteristics of Chemically Prepared ZnO Nanostructures on Silica Modified Polyaniline Nanocomposites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.548-549.196 ◽

2014 ◽

Vol 548-549 ◽

pp. 196-200 ◽

Cited By ~ 1

Author(s):

Katherine M. Emphasis ◽

Reynaldo M. Vequizo ◽

Rolando T. Canditato ◽

Majvell Kay G. Odarve ◽

Filchito Renè G. Bagsican ◽

...

Keyword(s):

Zinc Oxide ◽

Fourier Transform ◽

Ftir Spectroscopy ◽

Chemical Bath Deposition ◽

In Situ Polymerization ◽

Visible Region ◽

Optical Characteristics ◽

Zno Nanostructures ◽

Vis Spectroscopy

Zinc oxide (ZnO) on silica modified polyaniline (SM-PANI) was prepared via chemical bath deposition and in situ polymerization. The optical characteristics of the nanocomposites were investigated using ultraviolet-visible (UV-Vis) spectroscopy. The bands showed higher absorbance in the visible region. Fourier transform infrared (FTIR) spectroscopy revealed that there is an interaction between SM-PANI and ZnO.

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Crystal growth of nanostructured zinc oxide nanorods from the seed layer

Materials Science-Poland ◽

10.2478/msp-2018-0067 ◽

2018 ◽

Vol 36 (3) ◽

pp. 477-482

Author(s):

B.O. Adetoye ◽

A.B. Alabi ◽

T. Akomolafe ◽

P.B. Managutti ◽

N. Coppede ◽

...

Keyword(s):

Zinc Oxide ◽

Absorption Spectrum ◽

Zno Nanorods ◽

Zinc Oxide Nanorods ◽

Visible Range ◽

Zno Nanostructures ◽

Sem Images ◽

Zno Nanostructure ◽

Vis Spectroscopy ◽

Fto Glass

AbstractOne-dimensional (1D) zinc oxide (ZnO) nanostructures (nanorods) were synthesized on a glass slide and fluorine-doped tin oxide (SnO2/F or FTO) coated glass (FTO/glass) by a wet chemical method. The structural, morphological and optical analyses of the as-deposited ZnO nanostructures were performed by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and UV-Vis spectroscopy, respectively. The XRD results showed that the nanostructures as-deposited on the glass and the FTO/glass substrates were of ZnO wurtzite crystal structure, and the crystallite sizes estimated from the (0 0 2) planes were 60.832 nm and 64.876 nm, respectively. The SEM images showed the growth of densely oriented ZnO nanorods with a hexagonal-faceted morphology. The UV-Vis absorption spectrum revealed high absorbance properties in the ultraviolet range and low absorbance properties in the visible range. The optical energy band gap of the ZnO nanostructure was estimated to be 3.87 eV by the absorption spectrum fitting (ASF) method.

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Photostabilizing Efficiency of Acrylic-based Bamboo Exterior Coatings Combining Benzotriazole and Zinc Oxide Nanoparticles

Coatings ◽

10.3390/coatings9090533 ◽

2019 ◽

Vol 9 (9) ◽

pp. 533 ◽

Cited By ~ 2

Author(s):

Fei Rao ◽

Yahui Zhang ◽

Minzhen Bao ◽

Zhiyuan Zhang ◽

Yongjie Bao ◽

...

Keyword(s):

Zinc Oxide ◽

Zinc Oxide Nanoparticles ◽

Uv Light ◽

Synergistic Effects ◽

Color Space ◽

Attenuated Total Reflection ◽

Shielding Effect ◽

Oxide Nanoparticles ◽

Uv Shielding ◽

Vis Spectroscopy

Long-term exposure to ultraviolet (UV) light can degrade and discolor bamboo; thus, coatings to protect it from UV exposure are required, especially for outdoor use. Benzotriazole (BTZ) and zinc oxide nanoparticles (NZnO) are organic and inorganic UV absorbers commonly used in UV shielding coatings. This study investigated the photostabilizing efficiency of acrylic-based bamboo exterior coatings using a combination of BTZ and NZnO. Different film formulations covering bamboo substrates were irradiated with artificial UV light for 500 h to accelerate aging. The UV-shielding effect on bamboo beneath various films was determined by CIELAB color space and Fourier transform infrared (FTIR) analysis. The film effectiveness was analyzed by scanning electron microscopy, wettability, UV-vis spectroscopy, and FTIR-attenuated total reflection (ATR) spectroscopy. Films containing BTZ provided higher resistance to photodegradation and more effectively inhibited photodiscoloration of the bamboo substrates than those prepared solely with NZnO. After 500 h of UV irradiation, the BTZ–NZnO film containing 2 wt % BTZ and 1 wt % NZnO showed the best coating performance. Strong synergistic effects were detected in the BTZ–NZnO coatings, particularly for the 2:1 ratio formulation. This study also demonstrated the potential of combining BTZ and NZnO as additives for developing stable, effective UV-shielding bamboo exterior coatings for outdoor applications.

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Manganese-Doped Zinc Oxide Nanostructures as Potential Scaffold for Photocatalytic and Fluorescence Sensing Applications

Chemosensors ◽

10.3390/chemosensors8040120 ◽

2020 ◽

Vol 8 (4) ◽

pp. 120

Author(s):

Deepika Thakur ◽

Anshu Sharma ◽

Abhishek Awasthi ◽

Dharmender Singh Rana ◽

Dilbag Singh ◽

...

Keyword(s):

Zinc Oxide ◽

Zno Nanostructures ◽

Zinc Oxide Nanostructures ◽

Fluorescence Sensing ◽

X Ray ◽

Sensing Applications ◽

Oxide Nanostructures ◽

Vis Spectroscopy ◽

Doped Zno ◽

Mn Doped

Herein, we report the photocatalytic and fluorescence sensing applications of manganese-doped zinc oxide nanostructures synthesized by a solution combustion technique, using zinc nitrate as an oxidizer and urea as a fuel. The synthesized Mn-doped ZnO nanostructures have been analyzed in terms of their surface morphology, phase composition, elemental analysis, and optical properties with the help of scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and UV-Visible (UV-Vis) spectroscopy. A careful observation of the SEM micrograph reveals that the synthesized material was porous and grown in very high density. Due to a well-defined porous structure, the Mn-doped ZnO nanostructures can be used for the detection of ciprofloxacin, which was found to exhibit a significantly low limit of detection (LOD) value i.e., 10.05 µM. The synthesized Mn-doped ZnO nanostructures have been further analyzed for interfering studies, which reveals that the synthesized sensor material possesses very good selectivity toward ciprofloxacin, as it detects selectively even in the presence of other molecules. The synthesized Mn-doped ZnO nanostructures have been further analyzed for the photodegradation of methyl orange (MO) dye. The experimental results reveal that Mn-doped ZnO behaves as an efficient photocatalyst. The 85% degradation of MO has been achieved in 75 min using 0.15 g of Mn-doped ZnO nanostructures. The observed results clearly confirmed that the synthesized Mn-dopedZnO nanostructures are a potential scaffold for the fabrication of sensitive and robust chemical sensors as well as an efficient photocatalyst.

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Astrocytes Are More Vulnerable than Neurons to Silicon Dioxide Nanoparticle Toxicity in Vitro

Toxics ◽

10.3390/toxics8030051 ◽

2020 ◽

Vol 8 (3) ◽

pp. 51

Author(s):

Jorge Humberto Limón-Pacheco ◽

Natalie Jiménez-Barrios ◽

Alejandro Déciga-Alcaraz ◽

Adriana Martínez-Cuazitl ◽

Mónica Maribel Mata-Miranda ◽

...

Keyword(s):

Nucleic Acids ◽

Silicon Dioxide ◽

Culture Media ◽

Brain Cell ◽

Attenuated Total Reflection ◽

Random Coil ◽

Silicon Dioxide Nanoparticles ◽

Neurotoxic Effects ◽

Α Helix

Some studies have shown that silicon dioxide nanoparticles (SiO2-NPs) can reach different regions of the brain and cause toxicity; however, the consequences of SiO2-NPs exposure on the diverse brain cell lineages is limited. We aimed to investigate the neurotoxic effects of SiO2-NP (0–100 µg/mL) on rat astrocyte-rich cultures or neuron-rich cultures using scanning electron microscopy, Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR), FTIR microspectroscopy mapping (IQ mapping), and cell viability tests. SiO2-NPs were amorphous particles and aggregated in saline and culture media. Both astrocytes and neurons treated with SiO2-NPs showed alterations in cell morphology and changes in the IR spectral regions corresponding to nucleic acids, proteins, and lipids. The analysis by the second derivative revealed a significant decrease in the signal of the amide I (α-helix, parallel β-strand, and random coil) at the concentration of 10 µg/mL in astrocytes but not in neurons. IQ mapping confirmed changes in nucleic acids, proteins, and lipids in astrocytes; cell death was higher in astrocytes than in neurons (10–100 µg/mL). We conclude that astrocytes were more vulnerable than neurons to SiO2-NPs toxicity. Therefore, the evaluation of human exposure to SiO2-NPs and possible neurotoxic effects must be followed up.

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Engineering the shape of Zinc Oxide crystals via sonochemical or hydrothermal solution-based methods

MRS Proceedings ◽

10.1557/proc-1087-v06-04 ◽

2008 ◽

Vol 1087 ◽

Author(s):

Marco Palumbo ◽

Simon J. Henley ◽

Thierry Lutz ◽

Vlad Stolojan ◽

David Cox ◽

...

Keyword(s):

Zinc Oxide ◽

Self Assembly ◽

Hydrothermal Solution ◽

Good Control ◽

Transparent Conductors ◽

Zno Nanostructures ◽

Large Area ◽

Light Emitting Devices ◽

Wide Range ◽

Solution Methods

AbstractRecent results in the use of Zinc Oxide (ZnO) nano/submicron crystals in fields as diverse as sensors, UV lasers, solar cells, piezoelectric nanogenerators and light emitting devices have reinvigorated the interest of the scientific community in this material. To fully exploit the wide range of properties offered by ZnO, a good understanding of the crystal growth mechanism and related defects chemistry is necessary. However, a full picture of the interrelation between defects, processing and properties has not yet been completed, especially for the ZnO nanostructures that are now being synthesized. Furthermore, achieving good control in the shape of the crystal is also a very desirable feature based on the strong correlation there is between shape and properties in nanoscale materials. In this paper, the synthesis of ZnO nanostructures via two alternative aqueous solution methods - sonochemical and hydrothermal - will be presented, together with the influence that the addition of citric anions or variations in the concentration of the initial reactants have on the ZnO crystals shape. Foreseen applications might be in the field of sensors, transparent conductors and large area electronics possibly via ink-jet printing techniques or self-assembly methods.

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Combinational inhibitory action of essential oils and gamma irradiation for controlling Aspergillus flavus and Aspergillus parasiticus growth and their aflatoxins biosynthesis in vitro and in situ conditions

Food Science and Technology International ◽

10.1177/10820132211053086 ◽

2021 ◽

pp. 108201322110530

Author(s):

Hanan H Abdel-Khalek ◽

Ali AI Hammad ◽

Reham MMA El-Kader ◽

Khayria A Youssef ◽

Dalia AM Abdou

Keyword(s):

Essential Oils ◽

Aspergillus Flavus ◽

Aspergillus Parasiticus ◽

Fungal Growth ◽

Storage Period ◽

Complete Removal ◽

Γ Irradiation ◽

Star Anise ◽

In Situ Conditions

The purpose of this study was to investigate the effects of certain essential oils (star anise, lemon leaves, marjoram, fennel, and lavender) on the fungal growth of Aspergillus flavus and Aspergillus parasiticus and their production of aflatoxin B1 (AFB1). The degree of suppression of the aflatoxigenic strains’ growth and their production of AFB1 is mainly affected by the kind and the concentration of the tested essential oils (EOs). Star anise essential oil had the lowest minimum inhibitory concentration (0.5 and 1.0 μL/mL) against A. flavus and A. parasiticus, respectively, so it was the best among the five different oils. The study of liquid chromatography with tandem mass spectrometry revealed that star anise EO resulted in a 98% reduction in AFB1 without a breakdown of AFB1 products after treatment thus the complete removal of AFB1 was done without any toxic residues. The combination showed a synergistic effect, the combinational treatment between γ-irradiation at a low dose (2 kGy) and star anise EO at concentrate 0.5 μL/g destroyed A. flavus and A. parasiticus inoculated (individually) in sorghum and peanut, respectively throughout the storage period (8 weeks).

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Biosynthesis of selenium nanoparticles by Aspergillus flavus and Candida albicans and comparison of their effects with antifungal drugs

10.21203/rs.3.rs-194546/v1 ◽

2021 ◽

Author(s):

Mahdi Hosseini Bafghi ◽

Razieh Nazari ◽

Majid Darroudi ◽

Mohsen Zargar ◽

Hossein Zarrinfar

Keyword(s):

Candida Albicans ◽

Aspergillus Flavus ◽

Fungal Pathogens ◽

Chemical Properties ◽

Cost Effective ◽

Antifungal Drugs ◽

Selenium Nanoparticles ◽

Fungal Strains ◽

Vis Spectroscopy ◽

Physical And Chemical

Abstract Biosynthesis of nanoparticles can stand as a replacement for the available chemical and physical methods by offering new procedures as green syntheses that have proved to be simple, biocompatible, safe, and cost-effective. Considering how nanoparticles with a size of 1 to 100 nanometers contain unique physical and chemical properties, recent reports are indicative of observing the antifungal qualities of selenium nanoparticles (Se-NPs). Recently, the observance of antifungal resistance towards different species of these fungi is often reported. Therefore, due to the antifungal effects of biological nanoparticles, this study aimed to investigate the exertion of these nanoparticles and evaluate their effects on the growth of fungal pathogens. Se-NPs were biosynthesized by the application of wet reduction method, which included specific concentrations of Aspergillus flavus and Candida albicans. The presence of nanoparticles was confirmed by methods such as UV-Vis spectroscopy, FT-IR analysis, and FESEM electron microscope that involved FESEM and EDAX diagram. The fungal strains were cultured in sabouraud dextrose agar medium to perform the sensitivity test based on the minimum inhibitory concentration (MIC) method in duplicate. The utilization of Se-NPs at concentrations of 1 µg/ ml and below resulted in zero growth of fungal agents. However, their growth was inhibited by antifungal drugs at concentrations of 2 µg/ ml and higher. Based on the obtained results, biological nanoparticles produced by fungal agents at different concentrations exhibited favorable inhibitory effects on the growth of fungal strains.

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Green synthesis and antimicrobial activity of ZnO nanostructures Punica granatum shell extract

Green Processing and Synthesis ◽

10.1515/gps-2016-0190 ◽

2017 ◽

Vol 6 (3) ◽

Cited By ~ 2

Author(s):

Ercan Karaköse ◽

Hakan Çolak ◽

Fatih Duman

Keyword(s):

Antimicrobial Activity ◽

Zinc Oxide ◽

Green Synthesis ◽

Aqueous Extract ◽

New Technologies ◽

Punica Granatum ◽

Zno Nanostructures ◽

Zno Nps ◽

Potential Applications ◽

Environmentally Safe

AbstractThe manufacture of nanoparticles (NPs) is a new area of investigation due to potential applications related to the improvement of new technologies; in particular, environmentally safe manufactured nanomaterials have become a growing area within nanoscience. In this research, we synthesized zinc oxide (ZnO)-NPs using an aqueous extract of

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