Antimicrobial Effects of Ag and ZnO Nanoparticles

In the present study, antimicrobial activity of silver (Ag NPs) and Zinc oxide (ZnO NPs) nanoparticles synthesized from Pichia fermentans were tested against common human pathogens. The nanoparticles were biosynthesized and characterized by XRD, TEM, EDX and FTIR analysis. The average size of Ag NPs was 60nm and ZnO NPs was 28nm. The study on antimicrobial activity of individual and combined nanoparticles showed that the ZnO NPs had greater antimicrobial activity than Ag NPs. The combined Ag NPs and ZnO NPs showed greater antimicrobial properties than their individual performance.

World Journal of Environmental Research, 2018

Nanoscale materials and their unique properties make them attractive for research and health -related applications. Silver nanoparticles were synthesised and incorporated in zinc oxide (ZnO) thin films on glass and tissue, in order to study their effect on antibacterial activity. ZnO films with various contents of Ag nanoparticles were prepared by the sol –gel method. Xray diffraction revealed the polycrystalline structure of the films, scanning electron microscopy exhibited their dense and continuous structure and UV-visible spectroscopy for measurement and transmittance was at more than 87%. The absorbance peak of Ag NPS was centred at 351 nm. The diameter of Ag NPS was analysed by Zeta Sizer and the colloids ranged from 2 to 110 nm. The results indicate that ZnO with Ag NPs on tissue can resist the growth of this kind of bacteria, with the zone of inhibition of the bacteria ATTC 700603 at between 8 and 18 mm .Keywords: Ag nanoparticles, zinc oxide, tissue, antibacterial activity.

Nano LIFE, 2014

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 di...

The leaves of Aloe vera were extracted by boiling in presence of stabilizing agent (Ammonia) to synthesize Ag nanoparticles at concentration 3.5mg/ml.The Ag NPs were recognized with UV-VIS spectrophotometer at optical density in (390, 400 and 450) nm respectively, also with a scanning electron microscope. The image was between 50-500 nm. The concentrations of nanoparticles measured using atomic absorption spectrophotometer which gave different concentrations of nanoparticles (3.5, 3.8 and 4) mg/ml of green synthetic of nanoparticles. AgNanoparticles solid and colloid Zn nanoparticles (Ag and ZnO) were used. Biosynthetic of these nanoparticles had antibacterial activity of Escherichia coli and Staphylococcus aureus with concentration of 0.17 mg/ml, while colloid nanoparticles was 3.5 µg/ml. The colloid ZnO nanoparticles showed antifungal activity on the tested fungi (Aspergillus niger, Pencillum spp and Candida albican) with concentration 0.17 mg/ml. The cytotoxicity effect of Aloe V...

Journal of composites science, 2019

This work emphasizes the use of the silver decorative method to enhance the antibacterial activity of TiO 2 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-TiO 2 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 TiO 2 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.

Novel Research in Microbiology Journal, 2021

Nowadays, the use of nanoparticles (NPs) has become useful in the different application fields. The aim of this study was to investigate the in vitro antimicrobial potential of metalZnO nanoparticles (ZnO NPs) against several bacterial and fungal strains including; Escherichia coli (ATCC 25922), Bacillus cereus (ATCC 13753), Staphylococcus aureus (ATCC 8095), Pseudomonas aeruginosa (ATCC10662), Candida albicans (ATCC10231) and Aspergillus niger (AUMC3663). Results obtained by X-ray diffraction analysis (XRD) showed that the NPs size was in the range of 35.143.7 nm. Images of the scanning electron microscopy (SEM) demonstrated the rod shape nature of the ZnO NPs, and the semi-spherical shapes of the Zn9.7TM0.3O NPs. The effect of different concentrations of ZnO NPs on the in vitro growth of the bacterial and fungal strains was evaluated using the agar well diffusion assay. Current results showed that Cd-ZnO NP recorded the highest antimicrobial potency; expressing inhibition zones di...

Cellular and Molecular Biology, 2021

The economic approaches for manufacturing the nanoparticles with physical and chemical effects and limited resistance to antibiotics have been progressed recently due to the rise of microbial resistance to antibiotics. This research aimed to study the antimicrobial efficacy of silver nanoparticles Ag, ZnO, and Tio2 nanoparticles against Salmonella typhimurium and Brucella abortus and Candida albicans. Two isolates of Salmonella and two isolates of Brucella abortus were isolated from food spastically meat and blood specimens, respectively. Candida albicans were isolated from the patient&#39;s mouth with oral candidiasis (oral thrush) and confirmed diagnosis by API 20C test. The antimicrobial susceptibility of Salmonella typhimurium and B. abortus isolates were performed against nine different antibiotics. Silver nanoparticles consisting of AgNPs size (90) nm, ZnO NPs size (20, 50) nm as well as TiO2 NPs size (10, 50) nm, were used. UV-Visible spectrophotometer was used to characteriz...

2019

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.

Advanced Materials Proceedings, 2017

Three different types of nanoparticles were synthesised in this study, viz silver (Ag), zinc oxide (ZnO) and titanium dioxide (TiO 2) using different chemical methods. These materials were then characterised using Transmission Electron Microscopy (TEM), Fourier Transform Infra-Red Spectroscopy (FTIR), Ultraviolet Visible Spectroscopy (UV-Vis) and Thermal Gravimetric Analysis (TGA). The materials were also tested for anti-bacterial activity. TEM showed that the particles were in the nano-size range (1-100 nm). FTIR and UV-Vis Spectroscopy showed the different absorption bands of the synthesised nanoparticles, respectively. Silver nanoparticles showed greater antibacterial activity against several bacteria than titanium dioxide and zinc oxide nanoparticles. The highest inhibition was observed for Klebsiella pneumoniae. The results showed that antimicrobial activity of nanoparticles increases with increasing concentration of the nanoparticles.

International Journal of Advanced Science and Engineering, 2024

In the present work nanoparticles of silver (Ag) doped zinc oxide(ZnO) were successfully synthesized by the Co-precipitation method using zinc sulphate and polyvinylpyrrolidone (PVP) as the precursor materials. Ethylene glycol (EG) and (NaOH + Na2CO3) were used for the homogeneity and to maintain the pH value of the solution. It helps to make a stoichiometric solution of silver-doped zinc oxide nanoparticles. The samples were characterized by XRD, FTIR, DRS-UV, and FE-SEM with EDX. Antimicrobial activity was also studied for the synthesized material. XRD results show that the calcination temperature significantly affected the average particle size which indicates that undoped and Ag-doped ZnO crystals are in a hexagonal wurtzite structure. The antibacterial activity of the prepared samples was reported against pathogenic organisms like Escherichia coli, Pseudomonas, Staphylococcus aureus, (Gram-positive and Gram-negative bacteria) and for fungus Aspergillus, Candida, and Mucorsps, for all the compounds. These nanoparticles which have antimicrobial properties can be used in food preservation packing materials.