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Due to the wide applications of gold nanoparticles, there have been great demands for their synthesis recently. Chemical methods produce pure and Non-dispersive nanoparticles, but these are quite expensive and potentially toxic to the environment. It has been suggested that the use of biological organisms and their components could be a suitable alternative for the production of nanoparticle in an eco-friendly manner (green synthesis). Using plant extracts for nanoparticle synthesis can be advantageous over other biological processes because it eliminates the elaborate process of maintaining cell cultures and can also be suitably scaled up for large-scale synthesis. In this study leaf extracts of Water cress, were used for green synthesis of gold nanoparticles. Gold nanoparticles were formed by treating an aqueous HAuCl4 solution by different amount of plant leaf extract as reducing agent at different temperatures. UV–visible spectroscopy was used for monitoring of the reaction progress. The synthesized gold nanoparticles were characterized with Dynamic light scattering (DLS) size analyzer, Transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR). The results show that only a few minutes were required for the synthesis of gold nanoparticles at 60 °C and 80 °C by 1000 μl of plant extract, suggesting appropriate reaction rates in comparable to those of nanoparticle synthesis by chemical methods. TEM images showed that spherical nanoparticles (size, 10–50 nm) were obtained at higher temperatures and leaf broth concentrations. The analysis of FTIR bands show that the Polysaccharides and proteins are probably involved in the bio reduction and synthesis of nanoparticles.

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Backgrounds: Green synthesis of nanoparticles (NPs) is a simple, fast, and eco-friendly method which could be performed by various microorganisms or plant extracts. Silver NPs are well-known as antimicrobial and anti-fungal materials. They play an essential role in the control of tumors via their cytotoxic effects. Therefore, they have attracted significant attention for developing an effective treatment solution for cancer cells. This study aimed to investigate the potential of Penicillium chrysogenum for the synthesis of silver NPs and to evaluate their toxicity on liver cancer cell line (HepG2).
Materials & Methods: After synthesis of NPs usingP. chrysogenum, characterization of the synthesized NPs was performed by UV–Vis spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FTIR) was carried out to detect biomolecules that may be responsible for the synthesis and stabilization of NPs. The cytotoxic activity of the synthesized AgclNPs on HepG2 cell line was evaluated using MTT assay.
Findings: UV–Vis spectroscopy and XRD analysis confirmed the synthesis of AgclNPs using P. chrysogenum. TEM analysis revealed the spherical shape of AgclNPs with an average crystalline size of 15 to 45 nm. FTIR spectroscopy indicated the possible functional groups that could be responsible for the reduction of metal ions and the capping process. These nanoparticles showed a dose-dependent anticancer activity against HepG2 cells.
Conclusion: The results suggest that biosynthesized silver chloride nanoparticles could offer potential applications in cancer therapy.
 

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Aims: Bioproduction methods of nanoparticles are preferrabale to chemical and physical methods because of low energy and time expenditure. The aim of this study was to investigate the biological preparation of silver nanoparticles, using Artemisia sieberi.
Materials & Methods: In this experimental study, the extract of Artemisia sieberihas was used to produce silver nanoparticles by a simple, non-toxic, and low-cost method. Formation of silver nanoparticles was established despite the presence of an absorption peak at 490nm, using spectrophotometer. The size and shape of silver nanoparticles were shown using scanning electron microscopy. Precise size and change range of nanoparticles were measured by Particle Size Analysis (PSA). FT-IR results also indicated the role of different functional groups in the synthetic process.
Findings: The change in the color of the extract from pale yellow to light brown and absorption peak at about 490nm showed production of silver nanoparticles. The silver nanoparticles were mainly spherical and their diameter was in the range of 27nm to 65nm, and in some regions, they were stacked or scattered together. The mean size of nanoparticles was 70nm and the dispersion of nanoparticles was in the range of 40nm to 140nm.
Conclusion: The silver nanoparticles derived from the Artemisia are spherical and their mean size is about 70nm. Their dispersion is between 40nm and 140nm.

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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.
 

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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. 
 

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The green synthesis of nanoparticles is performed in a low-cost, environmentally friendly, and efficient manner. Compared to other methods of nanoparticle production, green synthesis has proven its superiority and unique benefits, eliminating the need for expensive, toxic, time-consuming, and undesirable methods. In this study, the green synthesis of silver nanoparticles using the extract of Tribulus terrestris was investigated. Tribulus terrestris is a medicinal plant used in traditional medicine to treat urinary and reproductive tract infections, especially burning, kidney stone elimination, relief of rheumatic pains, reduction of blood pressure, and stimulation of the liver. In this research, the morphology, size, and structural properties of nanoparticles were investigated using XRD, UV-visible, FT-IR, and SEM. Given the antibacterial and anticancer properties of the Tribulus terrestris extract and the importance of silver nanoparticles, the antimicrobial effects of silver nanoparticles were examined against a number of standard strains, as well as gram-negative and gram-positive bacteria. UV-visible spectroscopy revealed a peak in the 429 nm, indicating the presence of synthesized silver nanoparticles. The results of X-ray diffraction (XRD) also confirmed the formation of the crystalline structure of nanoparticles. The results of the non-growth halo diameter for Bacillus subtilis bacterium were more than that of Escherichia coli, in other words, Escherichia coli showed more resistance against synthesized nanoparticles. The results of this research show that the green synthesis of silver nanoparticles using milk thistle seed extract can be used as a suitable antibacterial agent against clinical pathogens.
 

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In this research Kelussia odoratissima Mozaff. leaf extract was used for the green synthesis of silver nanoparticles (AgNPs). At first we compared antioxidant activity of different extracts of K. odoratissima. Then solution containing silver nitrate was treated with the extract which showed high antioxidant activity. Synthesized AgNPs were evaluated by analyzing the excitation of surface plasmon resonance. TEM analysis was also used for nanoparticle characterization. Antibacterial activity of the solution containing AgNPs was measured by microdilution test. Common food contaminant bacteria such as gram-positive (Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes) and gram-negative (Escherichia coli O157: H7, Salmonella enterica and Pseudomonas aeruginosa)were used for the evaluation. The aqueous extract showed the highest antioxidant activity and the solution was used for the green synthesis of AgNPs. The particle diameters were calculated to be 20-40nm with -17 to -19.9 mV zeta potential. The TEM micrographs showed that the AgNPs are nearly spherical in shape and highly monodispersed. MIC of the AgNPs against gram-positive and gram-negative bacteria was between 0.012-0.025 and 0.006-0.012 mg/ml respectively.

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Objective: Recently, green synthesis of silver nanoparticles has been performed out through plants, fungi, bacteria, and algae because this is a simple, low-cost, and environmentally friendly method. This technique can be a suitable alternative to physical and chemical methods. In this study, we assess green synthesis of silver nanoparticles by the truffle fungus) Tuber spp. (extract and MTT assessment of its cytotoxicity.
Methods: We used the Tuber spp.Extract as the reducing agent for the biosynthesis of silver nanoparticles. The sizes, structural, optical and morphological properties of the nanoparticles were analyzed by FT-IR, X-ray diffraction and field emission scanning (transmission; TEM) electron microscope. The cytotoxicity effect of silver nanoparticles on cell lines was evaluated by the MTT assay after 24 h.
Result: UV-Vis spectrum exhibited an absorption band at around 400-450 nm that suggested the formation of biological silver nanoparticles. The size and morphological properties of nanoparticles were assessed by TEM which showed that the particles had spherical shapes with diameters of approximately 15-30 nm. The MTT assay revealed a dose- and time-dependent anti-proliferative effect of the silver nanoparticles.
Conclusion: The extract of Tuber spp.has the ability to reduce theAg⁺ ion to silver nanoparticles. Silver nanoparticles produced by green synthesis have good anti-proliferative effects compare to the Tuber spp. extract.