scholarly journals Synthesis of Chitosan/Zinc Oxide Nanoparticles Stabilized by Chitosan via Microwave Heating

Author(s):  
Nurul Amira Ahmad Yusof ◽  
Norashikin Mat Zain ◽  
Norlin Pauzi

Nowadays, zinc oxide (ZnO) has attracted attention in research and development because of its remarkable antibacterial properties. Chitosan/ZnO nanoparticles were successfully synthesized via microwave heating. The objectives of this work were to investigate the effect of stabilizer, power heating and time heating on size of chitosan/ZnO nanoparticles and to determine antibacterial activity against pathogenic bacteria, where chitosan was used as a stabilizing agent. Chitosan/ZnO nanoparticles were analyzed  by Fourier Transform Infra Red (FTIR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and Zetasizer instrument. The power heating and time heating were varied from 400 to 800 Watt and 4 to 8 minutes, respectively. The presence of chitosan has role on preventing the nanoparticles from agglomeration by producing a milky solution of chitosan/ZnO nanoparticles without any suspensions. The increase of power  and time heating improved the size of nanoparticles. The peak in FTIR spectrum at around 427 cm-1 was confirmed the existence of the ZnO phase. XRD patterns showed that the chitosan/ZnO nanoparticles materials were pure phase with average crystalline size is 130 nm. FESEM revealed that chitosan/ZnO nanoparticles were uniformly distributed with the mean value of size is 70 nm and spherical shaped. Further impact of power and time heating on the size of the chitosan/ZnO nanoparticles can be shown by a nanoparticles size distribution with the average of 30 to 90 nm. The results showed that chitosan/ZnO nanoparticles have displayed an antibacterial inhibition zone against Gram-positive S. aureus and Gram-negative E. coli which 16.0 and 13.3 mm, respectively. Chitosan/ZnO nanoparticles were synthesized in this work presented have potential application to prevent bacterial infections. Copyright © 2019 BCREC Group. All rights reserved 

2012 ◽  
Vol 506 ◽  
pp. 401-404
Author(s):  
T. Kaewsomboon ◽  
Komgrit Sawangkan ◽  
Chutimon Satirapipathkul

The antibacterial properties of konjac glucomannan (KGM) film containing two herb extracts (Atractylodes lancea and Saussurea lappa) at various concentrations was studied in this present work. This activity was tested against two pathogenic bacteria, Bacillus subtilis and Staphylococcus aureus. The results showed that the mean value of inhibition zone diameter of incorporated films with Saussurea lappa extracts were higher than those incorporating Atractylodes lancea extracts for all concentrations. The film incorporated with S. lappa extract had higher antibacterial activity against both bacteria than incorporated with A. lamcea. For all these levels, it can be seen that the KGM film had satisfactory physical properties and antibacterial activities.


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 584
Author(s):  
Shalendra Kumar ◽  
Faheem Ahmed ◽  
Nagih M. Shaalan ◽  
Osama Saber

Bio-inspired synthesis is a novel and attractive environmentally friendly route to generating inorganic materials. In this work, the preparation of CeO2 NPs using egg white and investigation of their antibacterial properties both in liquid and solid growth medium against Escherichia coli and Staphylococcus aureus bacteria were reported. The CeO2 nanoparticles were characterized using X-ray diffraction (XRD), Field emission transmission electron microscope (FETEM), UV-Vis, Raman, and antibacterial measurements. The results from XRD and TEM analysis showed that the prepared nanoparticles were a single phase in the nano regime (5–7 nm) with spherical shape and uniform size distribution. Optical properties reflected the characteristics peaks of CeO2 in the UV-Vis range with a bandgap ~2.80 eV. The antibacterial activity of the synthesized NPs was achieved under ambient conditions with different bacteria and the results showed that the properties were different for both the bacteria. The highest activity with an inhibition zone of about 22 mm against S. aureus was obtained as compared with the 19 mm zone of inhibition obtained with E.coli. This finding will be of major significance that indicates a possibility to develop CeO2 NPs as antibacterial agents against extensive microorganisms to control and prevent the spread and persistence of bacterial infections.


2021 ◽  
Vol 8 (1) ◽  
pp. 55-63
Author(s):  
Amir Nasser Alibeigi ◽  
Neda Javid ◽  
Majid Amiri Gharaghani ◽  
Zhila Honarmandrad ◽  
Fatemeh Parsaie

Background: The presence of antibiotics such as metronidazole in wastewater even at low concentrations requires searching for a suitable process such as advanced oxidation process (AOP) to reduce the level of pollutants to a standard level in water. Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc sulfate (ZnSO4 ) as a precursor, then, stabilized on stone and was used as a catalyst, in order to degrade metronidazole by photocalytic process. Effective factors on the removal efficiency of metronidazole including the initial metronidazole concentration, contact time, pH, and 0.9 gL-1 ZnO stabilized on the stone surface were investigated. Results: The X-ray diffraction (XRD) studies showed that the synthesized nanomaterials have hexagonal Wurtzite structure. Also, scanning electron microscopy (SEM) analysis revealed that the average crystalline size of the synthesized ZnO particles was in the range of 1.9-3.2 nm. The spectra represented a sharp absorption edge at 390 nm for ZnO nanoparticles corresponding to band gap of 3.168 eV. The BET-BJH specific surface area of the synthesized ZnO nanoparticles was 25.504 m2 /g. The EDS spectrum of ZnO nanoparticles showed four peaks, which were identified as Zn and O. The maximum removal efficiency was 98.36% for the synthetic solution under a specific condition (pH = 11, reaction time = 90 minutes, ZnO concentration = 0.9 gL-1, and the initial concentration of metronidazole = 10 mgL-1). The photocatalytic degradation was found to follow pseudo-first-order degradation kinetics. Conclusion: Therefore, the ZnO nanoparticles synthesized by thermal decomposition are suitable and effective photocatalytic materials for degradation of pharmaceutical contaminants.


2020 ◽  
Author(s):  
Leyla Mojtabavi ◽  
Amir Razavi

AbstractIn this work, we studied the effects of copper incorporation in the composition of bioactive glass. Three different glass compositions were synthesized with 0, 3, and 6 mol% of copper addition. X-Ray Diffraction (XRD) patterns confirmed that an amorphous microstructure was obtained for all three glass compositions. Results from Differential Thermal Analysis (DTA) showed that the copper addition in the glass lowers the glass transition temperature, from 646°C to 590°C when added at 6 mol%. X-ray Photoelectron (XPS) survey and high-resolution scans were performed to study the structural effects of copper addition in the glass. Results indicated that the incorporation of copper changes the ratio of bridging to non-birding oxygens in the structure. Glasses were further analyzed for their structure with Nuclear Magnetic Resonance (NMR) spectroscopy, which indicated that copper acts as a network modifier in the glass composition and copper-containing glasses show a less connected microstructure. Antibacterial efficacy of the glasses was analyzed against E. coli and S. epidermis. Copper-containing glasses showed a significantly higher inhibition zone compared to control glass. The glass with 6 mol% copper, exhibited inhibition zones of 9 and 16mm against E. coli and S. epidermis bacteria, respectively.


2014 ◽  
Vol 77 (9) ◽  
pp. 1599-1604 ◽  
Author(s):  
MAHBOUBEH MIRHOSSEINI ◽  
VAHID ARJMAND

Practical applications of different concentrations (0, 1, 2, 4, 6, and 8 mM) of zinc oxide (ZnO) suspensions containing 1% acetic acid were investigated against the pathogenic bacteria Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Bacillus cereus. ZnO suspensions (0, 1, 3, 6, and 8 mM) containing acetic acid had a significant inhibitory effect on the growth of L. monocytogenes, E. coli, and S. aureus during 12 h of incubation, and the 8 mM suspensions of ZnO were the most effective against all the strains. These data suggested that the antibacterial activity of ZnO was concentration dependent. Thus, 6 and 8 mM ZnO were selected for further studies in meat. ZnO nanoparticles reduced initial growth of all inoculated strains in meat. To our knowledge, this is the first report describing the antibacterial activity of ZnO nanoparticles in meat and indicates the potential of these nanoparticles as an antibacterial agent in the food industry.


2020 ◽  
Vol 20 (10) ◽  
pp. 5977-5996 ◽  
Author(s):  
Saee Gharpure ◽  
Balaprasad Ankamwar

With increase in incidence of multidrug resistant pathogens, there is a demand to adapt newer approaches in order to combat these diseases as traditional therapy is insufficient for their treatment. Use of nanotechnology provides a promising alternative as antimicrobial agents as against traditional antibiotics. Metal oxides have been exploited for a long times for their antimicrobial properties. Zinc oxide nanoparticles (ZnO NPs) are preferred over other metal oxide nanoparticles because of their bio-compatible nature and excellent antibacterial potentials. The basic mechanism of bactericidal nature of ZnO nanoparticles includes physical contact between ZnO nanoparticles and the bacterial cell wall, generation of reactive oxygen species (ROS) as well as free radicals and release of Zn2+ ions. This review focuses on different synthesis methods of ZnO nanoparticles, various analytical techniques frequently used for testing antibacterial properties, mechanism explaining antibacterial nature of ZnO nanoparticles as well as different factors affecting the antibacterial properties.


2011 ◽  
Vol 1 (1) ◽  
pp. 17 ◽  
Author(s):  
Surekha Challa ◽  
Kiran K. Rajam ◽  
Vishnu V. V. Satyanarayana Kasapu ◽  
Suresh Kumar Tanneeru ◽  
Venkata Siva Satyanarayana Kantamreddi

<em>Rhynchosia scarabaeoides </em>(L.) DC plant parts are extensively used by traditional healers in India to treat a variety of bacterial diseases, such as dysentery, diarrohea and skin disorders. This article reports the antibacterial activities of n-hexane, ethyl acetate and ethanol extracts belonging to the leaf, stem and root parts of <em>R. scarabaeoides</em> against five bacterial strains, <em>Bacillus subtilis</em>, <em>Escherichia coli</em>, <em>Klebseilla pneumonia</em>, <em>Proteus vulgaris</em> and <em>Staphylococcus aureus</em>, using an agar gel diffusion method. The range of inhibition zone (IZ) was found to be 15-24 mm and the minimum inhibitory activity (MIC) was found to be 1 mL/well. The IZ was found to be higher in ethyl acetate extracts while this was moderate in ethanol extracts, and no activity was seen with n-hexane extracts or root extracts. The MIC value of leaf ethyl acetate extract was found to be 1 mg against bacterial strains <em>P. vulgaris</em> and <em>S. aureus</em>, whereas 2 mg was found against <em>B. subtilis</em>, <em>K. pneumoniae</em> and <em>E. coli</em>. These results support the traditional usage of R. scarabaeoides plant parts in the treatment of bacterial infections. Interestingly, this plant was screened for antibacterial activity for the first time and was found to be active. Detailed chemical investigations are, therefore, warranted.


2019 ◽  
Vol 2 (1) ◽  
pp. 42-52
Author(s):  
Abdur Rehman ◽  
Saira Ahmad ◽  
Abdul Mateen ◽  
Huma Qamar ◽  
Mudaber Ahmad Mubashar ◽  
...  

Nanotechnology is the science, engineering and technology conducted at the scale that ranges between 1-100 nanometers. For the bio-application, evolution of nanotechnology is creating the concern of scientists towards the synthesis of nanoparticles. The nanoparticles have unique characteristics as compare to bulk materials. Zinc oxide (ZnO) is a matchless semiconductor and it has been under investigation due to its wide range of applications in various areas like biomedical, electronics, material science and optics. In the present work synthesis of ZnO nanoparticles was carried out by using simple chemical approach, Sol-gel method for being effective and inexpensive, by employing zinc acetate dehydrate Zn (CH3CO2)2.2H2O as a precursor and sodium hydroxide (NaOH) starch as a constant agent. The structural properties of resultant zinc oxide nanoparticles were investigated by X-ray diffraction (XRD) technique. The XRD data confirmed the hexagonal wurtzite structure of ZnO powder confirmed by JCPDS 36-1451 data. Particles size was calculated by Scherrer formula and calculated size was 30.14 nm. These nanoparticles were investigated for inhibition zone of bacterial strain Escherichia coli, a gram-negative microbe, at various concentrations of ZnO nanoparticles. Zinc oxide nanoparticles were very proficient for inhibition of growth of bacterial strain E. coli. The mechanism of ZnO NPs for antibacterial activity is release of reactive oxygen species which not only hydrolyze cell wall but cell membrane and cellular components as well providing a potential bactericidal effect.


2015 ◽  
Vol 6 (1) ◽  
pp. 148-155 ◽  
Author(s):  
Neha Mehta ◽  
Subhankar Basu ◽  
Arun Kumar

Zinc oxide (ZnO) nanoparticles are used for the synthesis of various materials. The nanoparticles, when entering into the environment, affect aquatic life. Their antibacterial properties deter the biological treatment process of wastewater treatment plants. The study focuses on the effectiveness of ultrafiltration (UF) membranes for the removal of ZnO nanoparticles. In this study, a commercial membrane was used for the separation of ZnO nanoparticles in the presence of natural organic matter (NOM) and alkalinity. Membrane flux and retention were studied for different concentrations of ZnO (1 mg/L, 10 mg/L, and 100 mg/L). Bare and fouled membranes were studied using a scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and atomic force microscopy (AFM). At higher concentrations (&gt;10 mg/L), ZnO nanoparticles tend to aggregate and increase in size, resulting in 95 to 98% retention. Further, the presence of NOM and alkalinity enhances particle–particle interactions and thereby promotes nanoparticle aggregation, which shows better retention even at lower concentrations (1–10 mg/L).


2017 ◽  
Vol 18 (3) ◽  
pp. 177-181 ◽  
Author(s):  
Roza Haghgoo ◽  
Motahareh Ahmadvand ◽  
Mohammad Nyakan ◽  
Mojtaba Jafari

ABSTRACT Aim This study aimed to assess the antimicrobial efficacy of 0, 0.5, 2, and 5 wt% nanosilver in conjunction with zinc oxide eugenol (ZOE) against Enterococcus faecalis. Materials and methods Nanosilver in 0.5, 2, and 5 wt% concentrations was added to ZOE and the antibacterial activity of the mixtures on E. faecalis was assessed using disk diffusion method, and the results were reported as the diameter of the growth inhibition zone. Results The diameters of the growth inhibition zones around 0, 0.5, 2, and 5 wt% concentrations of nanosilver particles were not significantly different at 24 and 48 hours and 1 week; however, the difference with the azithromycin disk was significant. Conclusion Considering the lack of a significant increase in the diameter of the growth inhibition zones around 0, 0.5, 2, and 5 wt% ZOE containing nanosilver, it appears that addition of nanosilver up to 5 wt% cannot improve the antibacterial properties of ZOE sealer against E. faecalis. Clinical significance Microorganisms present in the root canal system of primary teeth are mainly responsible for endodontic infections. Enterococcus faecalis is the most important cause of endodontic failure. Application of sealers that decrease the adhesion and colonization of bacteria, as well as susceptibility to bacterial infections can greatly help in this regard. Using these sealers in conjunction with antibacterial agents, such as nanosilver particles may yield higher antibacterial efficacy. How to cite this article Haghgoo R, Ahmadvand M, Nyakan M, Jafari M. Antimicrobial Efficacy of Mixtures of Nanosilver and Zinc Oxide Eugenol against Enterococcus faecalis. J Contemp Dent Pract 2017;18(3):177-181.


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