Synthesis of ZnO and Ag/ZnO Nanorods: Characterization and Synergistic In Vitro Biocidal Studies

2018 ◽  
Vol 24 (8) ◽  
pp. 5490-5495
Author(s):  
R. Radha Lakshmi ◽  
D Sruthi ◽  
K Prithiv ◽  
S Harippriya ◽  
K. R Aranganayagam
Keyword(s):  
Zno Nanorods ◽  
Wide Band ◽  
Hexagonal Wurtzite Structure ◽  
Nano Particles ◽  
Wide Band Gap ◽  
Chemical Route ◽  
E Coli ◽  
Bacteria And Fungi ◽  
Synthesized Materials

The ZnO semiconductor has gained substantial interest in the research community in part because of its large exciton binding energy (60 meV) and direct wide band gap (3.72 eV). ZnO and Ag doped ZnO (Agx Zn1−xO (where x = 0.01, 0.02 and 0.03)) were synthesized by using soft chemical route. The synthesized materials were characterized by using XRD, HRSEM, EDS and HRTEM. The powder XRD pattern indicates that the ZnO and Agx Zn1−xO (where x = 0.01, 0.02 and 0.03) samples exhibits hexagonal wurtzite structure and also the Ag doping decreases the grain size of ZnO nano particles. The micro structural characterizations (HRSEM and HRTEM) reveal the incorporation of Ag into the ZnO lattice and also the formation of nano rods. At the length, the antimicrobial response was also brought against human pathogenic Gram +ve (S. aureus), Gram −ve (E. coli) bacteria and Fungi (C. albicans). Thus the above work brings out the presence of antimicrobial response against the microbes from these nano composites.

scholarly journals Biosurfactants Induce Antimicrobial Peptide Production through the Activation of TmSpatzles in Tenebrio molitor

2020 ◽  
Vol 21 (17) ◽  
pp. 6090
Author(s):  
Tariku Tesfaye Edosa ◽  
Yong Hun Jo ◽  
Maryam Keshavarz ◽  
In Seon Kim ◽  
Yeon Soo Han
Keyword(s):  
Antimicrobial Peptide ◽  
Immune Activation ◽  
Tenebrio Molitor ◽  
Antimicrobial Activities ◽  
Iturin A ◽  
E Coli ◽  
Fat Bodies ◽  
Escherichia Coli Bacteria ◽  
Bacteria And Fungi

Biosurfactant immunomodulatory activities in mammals, nematodes, and plants have been investigated. However, the immune activation property of biosurfactants in insects has not been reported. Therefore, here, we studied the defense response triggered by lipopeptides (fengycin and iturin A), glycolipids (rhamnolipid), and cyclic polypeptides (bacitracin) in the coleopteran insect, mealworm Tenebrio molitor. The in vitro antimicrobial activities against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and fungi (Candida albicans) were assessed by mixing these pathogens with the hemolymph of biosurfactant-immune-activated larvae. E. coli growth was remarkably inhibited by this hemolymph. The antimicrobial peptide (AMP) induction results also revealed that all biosurfactants tested induced several AMPs, exclusively in hemocytes. The survivability analysis of T. molitor larvae challenged by E. coli (106 CFU/µL) at 24 h post biosurfactant-immune activation showed that fengycin, iturin A, and rhamnopid significantly increased survivability against E. coli. Biosurfactant-induced TmSpatzles activation was also monitored, and the results showed that TmSpz3 and TmSpz-like were upregulated in the hemocytes of iturin A-injected larvae, while TmSpz4 and TmSpz6 were upregulated in the fat bodies of the fengycin-, iturin A-, and rhamnolipid-injected larvae. Overall, these results suggest that lipopeptide and glycolipid biosurfactants induce the expression of AMPs in T. molitor via the activation of spätzle genes, thereby increasing the survivability of T. molitor against E. coli.

Structural and Electrical Properties of Hydrothermal Growth ZnO Nanorods

2015 ◽  
Vol 1109 ◽  
pp. 104-107
Author(s):  
K.L. Foo ◽  
U. Hashim ◽  
Chun Hong Voon ◽  
M. Kashif
Keyword(s):  
Electrical Properties ◽  
Zno Nanorods ◽  
Wide Band ◽  
Hydrothermal Growth ◽  
Oxide Semiconductor ◽  
Wide Band Gap ◽  
Interdigitated Electrode ◽  
Growth Technique ◽  
Xrd Pattern ◽  
Structural And Electrical Properties

ZnO nanorods, type of the metal-oxide semiconductor deposited on interdigitated electrode (IDE) substrate using hydrothermal growth technique. The growth ZnO nanorods was annealed in furnace at 500°C for 2 hours as to obtain highly crystallite of ZnO nanorods. XRD pattern indicated the synthesized ZnO nanorods have preferred orientation along the (002) plane. Moreover, FESEM images showed that the nanorods with the size less than 60 nanometer were successfully synthesized using hydrothermal growth technique. The investigation on optical properties using UV-Vis-NIR spectrophotometer confirmed ZnO is classified as a wide band gap semiconductor material. Furthermore, the growth ZnO nanorods which undergo electrical properties testing using dielectric analyzer and source meter show that the ZnO nanorods demonstrated rectifying behaviour.

scholarly journals Phytochemical characterization, anti-cancer and antimicrobial activity of isolated fractions of Alysicarpus vaginalis

2017 ◽  
Vol 12 (1) ◽  
pp. 77 ◽  
Author(s):  
Ganesh Tapadiya ◽  
Mayura A. Kale ◽  
Shweta Saboo
Keyword(s):  
Antimicrobial Activity ◽  
Cell Lines ◽  
Methanolic Extract ◽  
Hep G2 ◽  
Zone Of Inhibition ◽  
E Coli ◽  
Anti Cancer ◽  
Proliferative Assay ◽  
Bacteria And Fungi

<p class="Abstract">The methanolic extract of <em>Alysicarpus </em>vaginalis was selected for fractionation due to its known reported biological activity. The four fractions were separated and subjected for<em> in vitro</em> antimitotic and anti-proliferative assays along with anti-cancer activity on two human cancers cell lines (SK-MEL-2 and Hep-G2). The antimicrobial potential of fractions had been evaluated against bacteria and fungi. From all fractions, acetone and n-butanol fractions were effective against the cell lines. They show strong inhibitory action with mitotic index 6.2 and 8.4 mg/mL and IC<sub>50 </sub>values of anti-proliferative assay in between 19.7 to 14.2 mg/mL respectively, which was found to be comparable to the standard methothrexate 5.9 mg/mL and 13.2 mg/mL respectively. In antimicrobial activity, the zone of inhibition had been observed in the range of 12-27 mm and MIC value was found in the range of 0.2-0.1 mg/mL. The acetone fraction was found to be most active against fungi, and<em> E. coli</em> whereas chloroform and n-butanol fractions were more effective against <em>S. aureus</em> and <em>B. </em>subtilis. The phytochemical characterization by HPLC analysis indicated the presence of important polyphenolic and steroidal compounds.</p>

scholarly journals In vitro Effects of Muscodor albus and Three Volatile Components on Growth of Selected Postharvest Microorganisms

HortScience ◽  
2005 ◽  
Vol 40 (7) ◽  
pp. 2109-2114 ◽  
Author(s):  
Ali A. Ramin ◽  
P. Gordon Braun ◽  
Robert K. Prange ◽  
John M. DeLong
Keyword(s):  
Erwinia Carotovora ◽  
Isobutyric Acid ◽  
Penicillium Expansum ◽  
Volatile Components ◽  
E Coli ◽  
In Vitro Effects ◽  
Bacteria And Fungi ◽  
Air Circulation ◽  
Muscodor Albus

Biofumigation by volatiles of Muscodor albus Worapong, Strobel & W.M. Hess, an endophytic fungus, was investigated for the biological control of three postharvest fungi, Botrytis cinerea Pers., Penicillium expansum Link, and Sclerotinia sclerotiorum (Lib) de Bary, and three bacteria, Erwinia carotovora pv. carotovora (Jones) Bergey et al., Pseudomonas fluorescens Migula (isolate A7B), and Escherichia coli (strain K12). Bacteria and fungi on artificial media in petri dishes were exposed to volatiles produced by M. albus mycelium growing on rye seeds in sealed glass 4-L jars with or without air circulation for up to 48 hours. The amount of dry M. albus–rye seed culture varied from 0.25 to 1.25 g·L–1 of jar volume. Fan circulation of volatiles in jars increased efficacy and 0.25 g·L–1 with fan circulation was sufficient to kill or suppress all fungi and bacteria after 24 and 48 hours, respectively. Two major volatiles of M. albus, isobutyric acid (IBA) and 2-methyl-1-butanol (MB), and one minor one, ethyl butyrate (EB), varied in their control of the same postharvest fungi and bacteria. Among the three fungi, IBA killed or suppressed S. sclerotiorum, B. cinerea, and P. expansum at 40, 25, and 45 μL·L –1, respectively. MB killed or suppressed S. sclerotiorum, B. cinerea, and P. expansum at 75, 100, and 100 μL·L –1, respectively. EB was only able to kill S. sclerotiorum at 100 μL·L –1. Among the three bacteria, IBA killed or suppressed E. coli (K12), E. carotovora pv. carotovora, and P. fluorescens at 5, 12.5, and 12.5 μL·L–1, respectively. MB killed or suppressed E. coli (K12), E. carotovora pv. carotovora, and P. fluorescens at 100, 75, and 100 μL·L–1, respectively. EB did not control growth of the three bacteria. This study demonstrates the need for air circulation in M. albus, MB, and IBA treatments to optimize the efficacy of these potential postharvest agents of disease control.

scholarly journals Cefuroxime-Loaded Hydrogels for Prevention and Treatment of Bacterial Contamination of Open Wounds

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Pavlo Virych ◽  
Oksana Nadtoka ◽  
Volodymyr Doroschuk ◽  
Sergey Lelyushok ◽  
Vasyl Chumachenko ◽  
...  
Keyword(s):  
Wound Dressings ◽  
E Coli ◽  
Polyacrylamide Hydrogels ◽  
Wild Strains ◽  
Cross Links ◽  
Antibiotic Release ◽  
Synthesized Materials ◽  
Klebsiella Spp

Dextran/Sulfodextran-graft-polyacrylamide- and polyacrylamide-based hydrogels were synthesized by radical polymerization and loaded with cefuroxime to obtain antimicrobial wound dressings. Antibiotic release from the antibiotic-loaded hydrogels into an aqueous solution was studied by the HPLC-UV method. It is shown that cefuroxime-loaded Dextran/Sulfodextran-graft-polyacrylamide hydrogels release the antibiotic more slowly compared to polyacrylamide hydrogel with the same density of cross-links. Antibacterial activity of the synthesized materials was tested in vitro against wild strains of S. aureus, E. coli, and Klebsiella spp. The possibility of using the obtained antimicrobial hydrogels for the treatment of infected wounds was confirmed in vivo in a rat model.

scholarly journals Broad-Spectrum Antimicrobial Effects of Photocatalysis Using Titanium Dioxide Nanoparticles Are Strongly Potentiated by Addition of Potassium Iodide

2016 ◽  
Vol 60 (9) ◽  
pp. 5445-5453 ◽  
Author(s):  
Ying-Ying Huang ◽  
Hwanjun Choi ◽  
Yu Kushida ◽  
Brijesh Bhayana ◽  
Yuguang Wang ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Potassium Iodide ◽  
Environmental Remediation ◽  
Titanium Dioxide Nanoparticles ◽  
Wide Band ◽  
Dependent Manner ◽  
Wide Band Gap ◽  
Content Type ◽  
Uva Light ◽  
Bacteria And Fungi

ABSTRACTPhotocatalysis describes the excitation of titanium dioxide nanoparticles (a wide-band gap semiconductor) by UVA light to produce reactive oxygen species (ROS) that can destroy many organic molecules. This photocatalysis process is used for environmental remediation, while antimicrobial photocatalysis can kill many classes of microorganisms and can be used to sterilize water and surfaces and possibly to treat infections. Here we show that addition of the nontoxic inorganic salt potassium iodide to TiO2(P25) excited by UVA potentiated the killing of Gram-positive bacteria, Gram-negative bacteria, and fungi by up to 6 logs. The microbial killing depended on the concentration of TiO2, the fluence of UVA light, and the concentration of KI (the best effect was at 100 mM). There was formation of long-lived antimicrobial species (probably hypoiodite and iodine) in the reaction mixture (detected by adding bacteria after light), but short-lived antibacterial reactive species (bacteria present during light) produced more killing. Fluorescent probes for ROS (hydroxyl radical and singlet oxygen) were quenched by iodide. Tri-iodide (which has a peak at 350 nm and a blue product with starch) was produced by TiO2-UVA-KI but was much reduced when methicillin-resistantStaphylococcus aureus(MRSA) cells were also present. The model tyrosine substrateN-acetyl tyrosine ethyl ester was iodinated in a light dose-dependent manner. We conclude that UVA-excited TiO2in the presence of iodide produces reactive iodine intermediates during illumination that kill microbial cells and long-lived oxidized iodine products that kill after light has ended.

Synthesis and Structural Elucidation of Aminoacetylenic Derivatives of 7-Methoxy- 2-Naphthole as Antimicrobial Agents

2017 ◽  
Vol 9 (08) ◽  
Author(s):  
Abu- Safieh Rana ◽  
Muhi- Eldeen Zuhair ◽  
Alsarahni Aseel ◽  
Al-Kaissi Elham
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Naphthalene Derivatives ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Bacteria And Fungi ◽  
Aminoacetylenic Derivatives ◽  
Derivatives Of ◽  
Mic Value

A new series of 7-methoxy-2-[4-(t-amino-1-yl)oxy]-naphthalene derivatives; 7-methoxy-2-{[4-(2-methylpiperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ2), 7-methoxy-2-{[4-(2,6-dimethylpiperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ3), 7-methoxy-2{[4-(piperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ4), 7-methoxy-2-{[4-(pyrrolidine)but-2-yn-1-yl]oxy}-naphthalene (RZ5), 7-methoxy-2-{[4-(N-methylpiperazine)but-2-yn-1-yl]oxy}-naphthalene (RZ6), 7-methoxy -2-{[4-(hexamethyleneimine)but-2-yn-1-yl]oxy}-naphthalene (RZ7) were synthesized and screened in vitro as potential antimicrobial agents. Antimicrobial activity were evaluated by measuring the minimum inhibitory and bactericidal/fungicidal concentration (MIC, MBC and MFC). RZ2, RZ5, RZ6 and RZ7 showed the highest antimicrobial activity against S. aureus with MIC value 62.5 µg/ml, compounds RZ2, RZ4, RZ5, and RZ7 have the highest antimicrobial activity against B. subtilis with MIC vale 62.5 µg/ml, RZ3, RZ6 have the same antimicrobial activity with MIC value 125µg/ml, compounds. RZ4, RZ5, RZ6 and RZ7 have the highest antimicrobial activity against E. coli with MIC value 125 µg/ml, all compounds have the same MIC value against P. aeruginosa (125 µg/ml). RZ2, RZ4, RZ5, RZ6, RZ7 showed the highest antifungal activity with MIC of 62.5 µg/ml. In conclusion, the synthesized compounds showed good antimicrobial activity and promising potency against gram positive bacteria, gram negative bacteria and fungi.

Effect of Buffer Thickness on the Formation of ZnO Nanorods Grown by MOCVD

2007 ◽  
Vol 124-126 ◽  
pp. 101-104
Author(s):  
Dong Chan Kim ◽  
Bo Hyun Kong ◽  
Young Yi Kim ◽  
Hyung Koun Cho ◽  
Jeong Yong Lee ◽  
...  
Keyword(s):  
Large Scale ◽  
Zno Nanorods ◽  
Wide Band ◽  
Buffer Layers ◽  
Zno Films ◽  
Wide Band Gap ◽  
Si Substrates ◽  
Potential Applications ◽  
Zno Buffer Layer ◽  
Zno Semiconductor

ZnO semiconductor has a wide band gap of 3.37 eV and a large exciton binding energy of 60 meV, and displays excellent sensing and optical properties. In particular, ZnO based 1D nanowires and nanorods have received intensive attention because of their potential applications in various fields. We grew ZnO buffer layers prior to the growth of ZnO nanorods for the fabrication of the vertically well-aligned ZnO nanorods without any catalysts. The ZnO nanorods were grown on Si (111) substrates by vertical MOCVD. The ZnO buffer layers were grown with various thicknesses at 400 °C and their effect on the formation of ZnO nanorods at 300 °C was evaluated by FESEM, XRD, and PL. The synthesized ZnO nanorods on the ZnO film show a high quality, a large-scale uniformity, and a vertical alignment along the [0001]ZnO compared to those on the Si substrates showing the randomly inclined ZnO nanorods. For sample using ZnO buffer layer, 1D ZnO nanorods with diameters of 150-200 nm were successively fabricated at very low growth temperature, while for sample without ZnO buffer the ZnO films with rough surface were grown.

scholarly journals Microwave Assisted Growth of ZnO Nanorods and Nanopolypods Nanostructure Thin Films for Gas and Explosives Sensing

2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
A. K. Singh
Keyword(s):  
Thin Films ◽  
Recovery Time ◽  
Zno Nanorods ◽  
Hexagonal Wurtzite Structure ◽  
Liquefied Petroleum Gas ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
Microwave Assisted ◽  
Temperature Ranges

The growth of uniformly distributed and densely packed array of zinc oxide (ZnO) nanorods (NRs) and nanorods (NRs)/nanopolypods (NPPs) was successfully achieved through microwave-assisted chemical route at low temperature. The ZnO NRs and NRs/NPPs were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), and UV-Vis absorption spectroscopy. The ZnO NRs were of 100–150 nm diameter and 0.5–1 μm length, while the NPPs were of diameter about 150–200 nm and 1.5–2 μm pod length. The prepared films are polycrystalline in nature and highly oriented along (002) plane with a hexagonal wurtzite structure. These films were studied for the sensing properties of liquefied petroleum gas (LPG), oxygen, and hazardous explosives, that is, 2,4,6-trinitrotoluene (TNT) and cyclotrimethylenetrinitramines (RDX), in the temperature ranges of 25–425 °C and 100–200 °C, respectively. The grown nanostructure films showed reliable stable response to several on-off cycles, and reduction in sensor recovery time was found with the increase in temperature. ZnO NRs and NRs/NPPs showed better sensitivity and recovery time for both LPG and oxygen, as compared to the literature-reported results for ZnO thin films.

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