Showing 6 results for Copper Nanoparticles
Volume 11, Issue 1 (2-2025)
Abstract
Background: This research aimed to assess the antibacterial and anti-biofilm properties of copper nanoparticles (CuNPs) produced using Artemisia biennis Willd through an eco-friendly approach, targeting four pathogenic bacteria.
Materials & Methods: A. biennis Willd extract with unit numbers “15.62-125” was prepared through maceration, drying, and powdering. Particle size distribution (PSD), dynamic light scattering (DLS), zeta potential, X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR) tests were used to characterize the synthesized CuNPs. Minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), and sub-minimum inhibitory concentrations (sub-MICs) were determined to investigate the antibacterial and anti-biofilm activities of CuNPs against Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, and Klebsiella pneumoniae ATCC 13883.
Findings: CuNPs synthesized using A. biennis Willd extract exhibited a brown color change with particle sizes mainly 30-40 nm by PSD. DLS indicated uniform distribution and hydrodynamic synthesis of particles with a zeta potential of -37.8. XRD and FTIR confirmed copper nanoparticle biosynthesis. The MICs of CuNPs were 15.62-62.5 μg/mL, with S. aureus and K. pneumonia revealing the highest and lowest antimicrobial drug resistance, respectively. This trend was repeated for MBCs and sub-MICs, ranging from 15.62-125 and 7.8-31.25 μg/mL, respectively. Bacterial strains were unable to form biofilms at sub-MICs. The anti-biofilm effects of CuNPs were more significant on Gram-negative bacteria.
Conclusion: CuNPs synthesized using A. biennis Willd extract by a green method show promising anti-biofilm and antibacterial characteristics against bacteria, suggesting their potential for treating bacterial infections.
Hadis Kordzangeneh, Fereshteh Jookar Kashi,
Volume 13, Issue 4 (1-2023)
Abstract
This study aimed to isolate and identify bacteria from soils contaminated with copper and have access to a capable bacterial strain for producing copper nanoparticles (CuNPs). The present study showed the extracellular production of copper nanoparticles using strain Ta-31. The effect of various factors such as substrate, supernatant volume, enzyme inducer, and electron donor was investigated on the production process. The properties of synthesized nanoparticles were identified by using UV-Vis, FTIR, XRD, SEM, and EDS analysis.
Moreover, the growth curve of strain Ta-31 was plotted in the presence and absence of an enzyme inducer (concentration of 0.1 mM copper sulfate). After the phylogenetic analysis, 16S rDNA gene sequences were determined, and their phylogenetic tree of the selected strain was plotted. The results showed that the best conditions for producing CuNPs, glucose 1% as an electron donor, 2 mM copper sulfate, and 20 ml supernatant had the best production. Strain Ta-31 arrived at the end of the log phase and the beginning of the stationary phase after 15 h. CuNPs were spherical and irregular, and the size of CuNPs was more in the range of 30-40 nm. According to the results, strain Ta-31 belonged to Staphylococcus pasteuri sp. with 99.88% similarity.
Volume 19, Issue 126 (8-2022)
Abstract
The most important application of nanotechnology in the food industry is the production of active packaging with antimicrobial properties, packaging with special mechanical properties in terms of gas and heat exchange and nanosensors in intelligent packaging. The aim of this study was to investigate the antimicrobial effect of silver and copper nanocomposites on Escherichia coli and Staphylococcus aureus. Nanocomposites containing silver and copper nanoparticles in 1, 3, 5 and 7% percentages were produced by extrusion method and were subjected to nanometric analysis. Then, the antimicrobial test of nanocomposites was performed on commercial strains of Staphylococcus aureus and Escherichia coli by measuring the inhibition of growth in the culture medium. The data showed that the size of copper and silver nanoparticles was in the range of 20 to 50 nm and the dispersion of nanoparticles on the surface of nanocomposites was uniform with high purity. Antimicrobial test of nanocomposites showed that with increasing the percentage of nanoparticles, the diameter of the growth inhibition of nanocomposites increased significantly and the rate of inhibition of growth of silver nanoparticles was higher than copper (p≤0.05). Staphylococcus aureus was more sensitive to copper and silver nanoparticles than Escherichia coli (p≤0.05). The results of the present study showed that silver and copper nanocomposites with high antimicrobial properties can be used for food packaging.
Volume 20, Issue 137 (7-2023)
Abstract
Shelf life increasing of red meat has the great importance due to its perishable properties and consumers' demand to use food free synthetic preservatives. This study was aimed to investigate the antimicrobial and antioxidant effects of poly lactic acid film (PLA) containing different concentrations of ethanolic sumac extract (SE 1 and 3%) and copper oxide nanoparticles (CuO1 and 2%) on shelf life enhancement of the minced beef during cold storage. The samples were stored at 4 ± 1 °C for 12 days and analyzed at 0, 1, 3, 6, 9 and 12 days of the storage period. All of the treatments significantly (P≤0.05) decreased total viable count, psychrotrophic bacteria and Enterobacteriaceae spp. population as compared control group during the storage period. Total volatile basic nitrogen (TVB-N) and pH values of the non-packed samples (control) were significantly (P≤0.05) higher than the packed ones during the storage time. The combined treatments containing SE and CuO-NPs showed the highest efficiency in shelf life increasing of the cold stored minced beef in dose dependent manner. Based on the results, it can be concluded that the usage of biodegradable poly lactic acid film containing a complex of SE and CuO-NPs is effective packaging in the shelf life improvement of minced beef during 12 days of the refrigerated storage period.
Volume 21, Issue 147 (4-2024)
Abstract
In this study, mucilage was extracted from fenugreek seeds and essential oil from rosemary. The composite film of fenugreek seed mucilage and eggplant peel powder was prepared with copper nanoparticles (0, 2, 4%) and rosemary essential oil (0, 4, 8%). The physicochemical properties of the prepared films were investigated. According to the obtained results, with the increase of copper nanoparticles and rosemary essential oil, the thickness and antioxidant of the film increases. Humidity, water vapor permeability and solubility of the film decrease with the increase of copper nanoparticles and rosemary essential oil. Also, with the increase of copper nanoparticles and rosemary essential oil, the L* color indices increased and the brightness of the layers decreased significantly. Also, with the increase of copper nanoparticles, the color indices a* increased, but b* decreased. Also, with the increase of rosemary essential oil, the a* color indices have decreased, but the b* factor has increased. The results of antimicrobial activity showed that the addition of copper nanoparticles and rosemary essential oil made the film active against Staphylococcus aureus. Conclusion: The addition of copper nanoparticles and rosemary essential oil to edible films based on fenugreek seed mucilage and eggplant skin powder improved the thickness and antioxidant, solubility, moisture and permeability to water vapor, as well as weakening the brightness.
Volume 21, Issue 148 (5-2024)
Abstract
Adding copper nanoparticles and rosemary essential oil can improve the structural and mechanical properties of films based on fenugreek seed mucilage and eggplant skin powder. The aim of this study was to prepare edible films based on mucilage of fenugreek seeds and eggplant skin powder containing copper nanoparticles (0, 2, 4% w/w) and rosemary essential oil (0, 4, 8% w/v). Edible films were prepared based on mucilage of fenugreek seeds and eggplant peel powder, and copper nanoparticles (0, 2, 4%) and rosemary essential oil (0, 4, 8%) were added to it. The structural and mechanical properties of the prepared films were investigated. According to the obtained results, increasing the amount of copper nanoparticles and rosemary essential oil in the film decreased the mechanical properties of the films. According to the obtained results, increasing the amount of copper nanoparticles and rosemary essential oil in the film decreased the mechanical texture of the films. X-ray diffraction (XRD) analysis showed that copper nanoparticles were physically combined with fenugreek seed mucilage polymer and eggplant skin powder, resulting in the strengthening of the crystal structure. Fourier transform infrared (FTIR) results confirmed the physical presence of copper nanoparticles in the polymer matrix. The results of the scanning electron microscope (SEM) showed that the surface morphology of the nanocomposite film is heterogeneous compared to fenugreek seed mucilage and eggplant skin powder. Exposure of the prepared detector film to different pHs led to the change of the color of the films from red to yellow. These color changes of the films were consistent with the color changes of the anthocyanin solution. The addition of copper nanoparticles and rosemary essential oil to edible films based on fenugreek seed mucilage and eggplant skin powder improved the Fourier transform infrared (FTIR) of the films, and also weakened the mechanical properties.
