scholarly journals Effect of Silver Decoration and Light Irradiation on the Antibacterial Activity of TiO2 and ZnO Nanoparticles

Author(s):  
Van Thang Nguyen ◽  
Tien Viet Vu ◽  
The Huu Nguyen ◽  
Tuan Anh Nguyen ◽  
Thien Vuong Nguyen ◽  
...  

This work emphasizes to use silver decorative method to enhance the antibacterial activity of TiO2 and ZnO nanoparticles. These silver decorated nanoparticles (hybrid nanoparticles) were synthesized by using sodium borohydride as a reducing agent, with the weight ratio of Ag precursors: oxide nanoparticles = 1: 30. The morphology and optical property of these hybrid nanoparticles were investigated using transmission electron microscopy (TEM) and UV–vis spectroscopy. The agar-well diffusion method was used to evaluate their antibacterial activity against both Staphylococcus aureus and Escherichia coli bacteria, with or without light irradiation. The TEM images indicated clearly that silver nanoparticles (AgNPs, 5-10 nm) were well deposited on the surface of nano-TiO2 particles (30-60 nm). Besides, smaller AgNPs (< 2 nm) were dispersed on the surface of nano-ZnO particles (20-50 nm). UV-vis spectra confirmed that the hybridization of Ag and oxide nanoparticles led to shift the absorption edge of oxide nanoparticles to the lower energy region (visible region). The antibacterial tests indicated that both oxide pure nanoparticles did not exhibit inhibitory against bacteria, with or without light irradiation. However, the presence of AgNPs in their hybrids, even at low content (< 40 mg/mL) leads to a good antibacterial activity and the higher inhibition zones under light irradiation as compared to that in dark was observed.

2019 ◽  
Vol 3 (2) ◽  
pp. 61 ◽  
Author(s):  
Van Thang Nguyen ◽  
Viet Tien Vu ◽  
The Huu Nguyen ◽  
Tuan Anh Nguyen ◽  
Van Khanh Tran ◽  
...  

This work emphasizes the use of the silver decorative method to enhance the antibacterial activity of TiO2 and ZnO nanoparticles. These silver-decorated nanoparticles (hybrid nanoparticles) were synthesized using sodium borohydride as a reducing agent, with the weight ratio of Ag precursors/oxide nanoparticles = 1:30. The morphology and optical properties of these hybrid nanoparticles were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD) patterns, and UV-Vis spectroscopy. The agar-well diffusion method was used to evaluate their antibacterial activity against both Staphylococcus aureus and Escherichia coli bacteria, with or without light irradiation. The TEM images indicated clearly that silver nanoparticles (AgNPs, 5–10 nm) were well deposited on the surface of nano-TiO2 particles (30–60 nm). In addition to this, bigger AgNPs (<20 nm) were dispersed on the surface of nano-ZnO particles (30–50 nm). XRD patterns confirmed the presence of AgNPs in both Ag-decorated TiO2 and Ag-decorated ZnO nanoparticles. UV-Vis spectra confirmed that the hybridization of Ag and oxide nanoparticles led to a shift in the absorption edge of oxide nanoparticles to the lower energy region (visible region). The antibacterial tests indicated that both oxide pure nanoparticles did not exhibit inhibitory effects against bacteria, with or without light irradiation. However, the presence of AgNPs in their hybrids, even at low content (<40 mg/mL), leads to a good antibacterial activity, and higher inhibition zones under light irradiation as compared to those in dark were observed.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Meron Girma Demissie ◽  
Fedlu Kedir Sabir ◽  
Gemechu Deressa Edossa ◽  
Bedasa Abdisa Gonfa

The synthesis of metal oxide nanoparticles with the use of medicinal plant extract is a promising alternative to the conventional chemical method. This work aimed to synthesize zinc oxide nanoparticles using a green approach from indigenous “Koseret” Lippia adoensis leaf extract which is an endemic medicinal plant and cultivated in home gardens of different regions of Ethiopia. The biosynthesized zinc oxide nanoparticles were characterized using thermogravimetric analysis, X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy, and Fourier transform infrared spectroscopy. Furthermore, this study also evaluated the antibacterial activity of the synthesized ZnO nanoparticles against clinical and standard strains of Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, and Enterococcus faecalis by the disc diffusion method. According to the result of this study, ZnO nanoparticles synthesized using Lippia adoensis leaf extract showed promising result against both Gram-positive and Gram-negative bacterial strains with a maximum inhibition zone of 14 mm and 12 mm, respectively, using uncalcinated form of the synthesized ZnO nanoparticles.


2019 ◽  
Vol 15 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Raja Adibah Raja Ahmad ◽  
Zawati Harun ◽  
Mohd Hafiz Dzarfan Othman ◽  
Hatijah Basri ◽  
Muhamad Zaini Yunos ◽  
...  

Biosynthesis of metallic nanoparticles using plants, enzymes, and microorganism have been known as eco-friendly alternatives to conventional physical and chemical methods. Recently, the biological synthesis of nanoparticles has been a keen interest amongst researchers and scientist due to its simple technique, eco-friendliness, non-toxic, inexpensive and potential to perform in antibacterial activity. Thus, in this current work, the synthesis of zinc oxide (ZnO) nanoparticles using reduction agent from fruit extracts of Ananas Comosus is reported. The biosynthesized zinc oxide was characterized using Field Emission Scanning Electron Microscope (FESEM) with Energy Dispersive X-ray analysis (EDX), UV-Vis absorption spectroscopy and X-ray diffraction (XRD). The average size of the nanoparticles was found to be in the range of 30-57nm. The antibacterial activity of ZnO nanoparticles was carried out via agar diffusion method against pathogenic organisms. It is observed that the biosynthesized ZnO in the process has the efficient antibacterial activity. In conclusion, the green synthesis of zinc oxide nanoparticles using the fruit extract of Ananas Comosus is considered as a potential additive to substitute other metal oxides such as silver (Ag) and titanium dioxide (TiO2)but also provide antibacterial effect that able to enhance the nanoparticle performance.


Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.


2016 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Pramudita Putri Kusuma ◽  
Ganjar Fadillah ◽  
Husna Syaima ◽  
Teguh Endah Saraswati

<p>The addition of garlic powder to gelatin from chicken claw waste was potentially developed as a natural preservative in food, especially for meat. Preparation of gelatin/garlic biocomposite was performed in three stages: synthesis of gelatin from chicken claw, garlic powder preparation as allicin source and preparation of biocomposite gelatin/garlic. The preparation of dry biocomposites was done by weighing the gelatin and garlic powder in weight ratio of 1 : 1 and 1 : 2 (w/w) in the total mass of 0.75 grams. For wet biocomposite preparation, the mixture of the powder was solved in 5 mL of lactic acid 2 %. Functional groups of gelatin, garlic and biocomposite were analyzed by <em>f</em><em>ourier transform infrared spectroscopy</em> (FTIR). The antibacterial activity of biocomposite against <em>Staphylococcus aureus</em> were tested using disc diffusion method. This test was performed on garlic powder, solvent and gelatin/garlic biocomposites powder in the ratio of 1 : 1 and 1 : 2 in 2 % lactic acid solvent. The biocomposite with a weight ratio of gelatin : garlic of  1 : 1 had the optimum diameter of inhibition zone. The effectiveness of biocomposite gelatin/garlic as natural preservative applied in meat was also physically studied by organoleptic analysis. Organoleptic analysis through the hedonic test was conducted on the parameters of color, smell, and texture of gelatin/garlic biocomposites-coated meat. The results showed that the addition of garlic can increase the effectiveness of gelatin as a natural preservative of meat for four days stored in closed packaging at room temperature.</p>


Author(s):  
Srijan Sunar ◽  
Rajeshkumar S ◽  
Anitha Roy ◽  
Lakshmi T

Copper nanoparticles makes important progress in the area of nanotechnology and nanomedicine due to their good optical, electrical and anti-fungal/bacterial application. It is prepared using some methods such as vacuum vapour deposition, microwave irradiation methods, chemical reduction and laser ablation. The chemical reduction method is simple, inexpensive and gives a liable control of geometrical nanoparticle characteristics like size and shape. 20 millimolar of 80 ml copper sulphate prepared using double distilled water. The plant extract is added with the metal solution and was made into 100 ml solution. The synthesised nanoparticles solution is preliminarily characterized by using UV- vis-spectroscopy, 3ml of the solution is taken in curette and scanned in double beam UV-vis- spectrophotometer from 300 nm to 700 nm wavelength. The agar well diffusion method is used. Different concentration of Cu NPs was tested against Staphylococcus aureus, Streptococcus mutans (gram +), Enterococcus sp and Pseudomonas sp. The result reveals that Moringa Oleifera mediated with copper nanoparticles show effective antibacterial activity. CuNPs ex significantly higher activity with an increase in the zone of inhibition diameter. The plant extract is observed to be dark green, and the copper nanoparticles are seen to be in light greenish in colour. They can be used in toothpaste and oral medicines due to their antibacterial activity. Nanoparticles are expected to be used in future for the effective drug systems and immunity against diseases.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mona A. Alqahtani ◽  
Monerah R. Al Othman ◽  
Afrah E. Mohammed

Abstract Recently, increase bacterial resistance to antimicrobial compounds issue constitutes a real threat to human health. One of the useful materials for bacterial control is Silver nanoparticles (AgNPs). Researchers tend to use biogenic agents to synthesize stable and safe AgNPs. The principal aim of this study was to investigate the ability of lichen in AgNPs formation and to find out their suppression ability to MDR bacteria as well as their cytotoxic activity. In the current study, lichens (Xanthoria parietina, Flavopunctelia flaventior) were collected from the south of the Kingdom of Saudi Arabia. Lichens methanolic extracts were used for conversion of Ag ions to AgNPs. Prepared biogenic AgNPs were characterized by Ultraviolet–Visible (UV–Vis) Spectroscopy, Transmission electron microscopy (TEM), Dynamic Light Scattering (DLS) and Zeta potential and Energy-Dispersive X-ray Spectroscopy (EDS). Lichens Secondary metabolites were determined by Fourier-Transform Infrared Spectroscopy (FTIR) and Gas Chromatography–Mass Spectrometry (GC–MS). The antibacterial activity and synergistic effect of AgNPs were evaluated against pathogenic bacteria, including gram-positive; Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococcus (VRE), and gram-negative; (Pseudomonas aeruginosa, Escherichia coli) as well as the reference strains (ATCC) using the agar disk diffusion method. Cytotoxic effect of biogenic AgNPs was tested against HCT 116 (Human Colorectal Cancer cell), MDA-MB-231 (Breast cancer cell), and FaDu (Pharynx cancer cell) by MTT test. TEM imaging showed well-dispersed spherical particles of 1–40 nm size as well as zeta size showed 69–145 nm. Furthermore, FTIR and GC–MS identified various lichen chemical molecules. On the other hand, the highest antibacterial activity of AgNPs was noticed against P. aeruginosa, followed by MRSA, VRE, and E. coli. AgNPs influence on gram-negative bacteria was greater than that on gram-positive bacteria and their synergistic effect with some antibiotics was noted against examined microbes. Moreover, higher cytotoxicity for biogenic AgNPs against FaDu and HCT 116 cell line in relation to MDA-MB-231 was noted. Given the current findings, the biogenic AgNPs mediated by lichens had positive antibacterial, synergistic and cytotoxic powers. Therefore, they might be considered as a promising candidate to combat the multi-drug resistance organisms and some cancer cells.


2020 ◽  
Vol 1 (1) ◽  
pp. 51-58
Author(s):  
Sharmila Pradhan ◽  
Rajeswori Shrestha ◽  
Khuma Bhandari

This research is focused on bio-synthesis of Copper nanoparticles (CuNPs) using lemon extract to study the effect of various parameters on synthesis and to explore antibacterial activity. The biomolecules present in lemon extract act as self reducing and stabilizing agent. The synthesis of CuNPs was found to be affected by various parameters like volume of the lemon extract, concentration of the precursor and the temperature etc. Preliminary characterization of formation of nanoparticles were done by color change and UV-visible (UV-vis) spectroscopy. Elemental composition of the prepared sample was determined via Energy Dispersive X-ray (EDX) Spectroscopy. Presence of important functional groups associated with biomolecules is well characterized by Fourier Transform Infrared spectroscopy (FTIR). Scanning Electron Microscopy (SEM ) revealed the formation agglomerated CuNPs of different shape and sizes and the X-ray diffraction pattern showed the formation of purely crystalline nature of CuNPs. Finally, agar well diffusion method showed that CuNPs have potential antibacterial activity against Gram-ve bacteria compared to Gram +ve bacteria.


2016 ◽  
Vol 12 (1) ◽  
Author(s):  
Pramudita Putri Kusuma

The addition of garlic powder to gelatin from chicken claw waste was potentially developed as a natural preservative in food, especially for meat. Preparation of gelatin/garlic biocomposite was performed in three stages: synthesis of gelatin from chicken claw, garlic powder preparation as allicin source and preparation of biocomposite gelatin/garlic. The preparation of dry biocomposites was done by weighing the gelatin and garlic powder in weight ratio of 1 : 1 and 1 : 2 (w/w) in the total mass of 0.75 grams. For wet biocomposite preparation, the mixture of the powder was solved in 5 mL of lactic acid 2 %. Functional groups of gelatin, garlic and biocomposite were analyzed by <em>f</em><em>ourier transform infrared spectroscopy</em> (FTIR). The antibacterial activity of biocomposite against <em>Staphylococcus aureus</em> were tested using disc diffusion method. This test was performed on garlic powder, solvent and gelatin/garlic biocomposites powder in the ratio of 1 : 1 and 1 : 2 in 2 % lactic acid solvent. The biocomposite with a weight ratio of gelatin : garlic of  1 : 1 had the optimum diameter of inhibition zone. The effectiveness of biocomposite gelatin/garlic as natural preservative applied in meat was also physically studied by organoleptic analysis. Organoleptic analysis through the hedonic test was conducted on the parameters of color, smell, and texture of gelatin/garlic biocomposites-coated meat. The results showed that the addition of garlic can increase the effectiveness of gelatin as a natural preservative of meat for four days stored in closed packaging at room temperature.


2021 ◽  
Vol 33 (3) ◽  
pp. 515-520
Author(s):  
N. Ahalya ◽  
P. Dhamodhar ◽  
A.D. Vaishnavi

In present study, zinc oxide nanoparticles were synthesised using Syzygium aromaticum and characterized using UV visible spectroscopy, SEM, XRD and FTIR techniques. The characteristic hexagonal structure of the ZnO nanoparticles was confirmed through XRD analysis. The UV-Visible spectrum showed a strong absorbance at 366 nm confirming the presence of ZnO and the peak at 496 cm-1 in FTIR indicated the Zn-O stretch bond. Average size of the zinc oxide nanoparticles obtained from SEM analysis was found to be 86 nm. The zinc oxide nanoparticles exhibited better antibacterial activity than clove extract, when tested against clinical isolates of Streptococcus mutans. The nanoparticles incorporated into the dental restorative material, glass ionomer cement (GIC) were tested against S. mutans and exhibited better antibacterial activity than clove extract. Glass ionomer cement (GIC) did not exhibit antibacterial activity alone, but the incorporation of ZnO nanoparticles into GIC significantly improved antibacterial activity. Hence, ZnO embedded GIC is a promising material in restorative dentistry for preventing the recurrence of dental caries.


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