Green Synthesis of Uncoated and Olive Leaf Extract-Coated Silver Nanoparticles: Sunlight Photocatalytic, Antiparasitic, and Antifungal Activities.

The circular economy, which attempts to decrease agricultural waste while also improving sustainable development through the production of sustainable products from waste and by-products, is currently one of the main objectives of environmental research. Taking this view, this study used a green approach to synthesize two forms of silver nanoparticles: coated silver nanoparticles with olive leaf extract (Ag-olive) and uncoated pure silver nanoparticles (Ag-pure), which were produced by the calcination of Ag-olive at 550 °C. The extract and the fabricated nanoparticles were characterized by a variety of physicochemical techniques, including high-performance liquid chromatography (HPLC), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Adult ticks (Hyalomma dromedarii) (Acari: Ixodidae) were used in this study to evaluate the antiparasitic activity of synthesized nanoparticles and extract. Furthermore, the antifungal activity was evaluated against Aspergillus aculeatus strain N (MW958085), Fuserium oxysporum (MT550034), and Alternaria tenuissiuma (MT550036). In both antiparasitic and antifungal tests, the as-synthesized Ag-olive showed higher inhibition activity than Ag-pure and olive leaf extract. The findings of this research suggest that Ag-olive may be a powerful and eco-friendly antiparasitic and antifungal agent. Ag-pure was also evaluated as a photocatalyst under sunlight for the detoxification of Eri-chrome-black T (EBT), methylene blue (MB), methyl orange (MO), and rhodamine B (RhB).

Photocatalytic Degradation of Rhodamine-B and Water Densification via Eco-Friendly Synthesized Cr2O3 and Ag@Cr2O3 Using Garlic Peel Aqueous Extract.

The purification and densification of wastewater play an important role in water recycling, especially if the materials used in water recycling are other types of recycled waste. Therefore, considering this view in this study, the biosynthesis of silver-decorated chromium oxide nanoparticles utilizing a wasted Allium sativum (garlic) peel extract is investigated. The aqueous extract of garlic peel (GPE) was treated with silver nitrate, chromium nitrate, and a mixture of silver nitrate and chromium nitrate to synthesize silver nanoparticles (Ag-garlic), chromium oxide nanoparticles (Cr2O3-garlic), and silver-decorated chromium oxide nanoparticles (Ag@Cr2O3-garlic), respectively. The synthesized nanoparticles were elucidated via thermal gravimetric analysis (TGA), infrared spectra (FT-IR), absorption spectra (UV-Vis), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Antimicrobial activity studies were conducted against waterborne germs, bacterial strains (Bacillus subtilis, Enterococcus faecium, Escherichia coli, and Pseudomonas aeruginosa), and fungal strains (Alternaria porri, Aspergillus flavus, Aspergillus niger, Fuserium oxysporum, and Trichoderma longibrachiatum) and showed significant levels of antimicrobial activity. The results revealed that Ag@Cr2O3 significantly improved antimicrobial activity due to their synergistic effect. The photocatalytic activity of nanoparticles was assessed using Rhodamine B dye (5 ppm) under solar irradiation. Cr2O3-garlic exhibited the best activity as a photocatalyst among the studied nanoparticles, with 97.5% degradation efficiency under optimal conditions.

Phytosynthesis via wasted onion peel extract of samarium oxide/silver core/shell nanoparticles for excellent inhibition of microbes.

The aqueous onion peel extract (OPE) was used to synthesize silver nanoparticles (Ag-onion), samarium oxide nanoparticles (Sm2O3-onion), and silver/samarium oxide core/shell nanoparticles (Ag@Sm2O3-onion). The produced nanoparticles were characterized by thermal gravimetric analysis (TGA), infrared spectra (FT-IR), absorption spectra (UV-Vis), energy band gap, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), zeta potential, and transmission electron microscopy (TEM). OPE and NPs were tested for the disinfection of some water microbes. XRD analysis exhibited an amorphous structure of samarium oxide in both Sm2O3-onion and Ag@ Sm2O3-onion. The isolated bacteria from the water sample were Bacillus subtilis (OQ073500) and Escherichia coli (MW534699), while the isolated fungi were Alternaria brassicae (MZ266540), Aspergillus flavus (MT550030), Aspergillus penicillioides (MW957971), Pythium ultimum (MW830915), Verticillium dahlia (MW830379), Fusarium acuminatum (MZ266538), Candida albicans (MW534712), and Candida parapsilosis (MW960416). High levels of antimicrobial activity were seen in both the nanoparticles and the aqueous onion peel extract. Based on experimental results, Ag@Sm2O3 demonstrated the highest activity as an effective disinfectant, indicating the effectiveness of the modification process.

High Antiparasitic and Antimicrobial Performance of Biosynthesized NiO Nanoparticles via Wasted Olive Leaf Extract.

Background: Nowadays, recycling agricultural waste is of the utmost importance in the world for the production of valuable bioactive compounds and environmental protection. Olive leaf bioactive compounds have a significant potential impact on the pharmaceutical industry. These compounds possess remarkable biological characteristics, including antimicrobial, antiviral, anti-inflammatory, hypoglycemic, and antioxidant properties. Methods: The present study demonstrates a green synthetic approach for the fabrication of nickel oxide nanoparticles (NiO-olive) using aqueous wasted olive leaf extract. Calcination of NiO-olive at 500°C led to the fabrication of pure NiO nanoparticles (NiO-pure). Different techniques, such as thermal gravimetric analysis (TGA), Fourier-transform infrared spectra (FTIR), ultraviolet-visible spectra (UV-Vis), X-ray diffraction (XRD), scanning electron microscopy (SEM) fitted with energy-dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM), were used to characterize both NiO-olive and NiO-pure. The extract and nanoparticles were assessed for antiparasitic activity against adult ticks (Hyalomma dromedarii) and antimicrobial activity against Bacillus cereus, Pseudomonas aeruginosa, Aspergillus niger, and Candida albicans. Results: From XRD, the crystal sizes of NiO-olive and NiO-pure were 32.94 nm and 13.85 nm, respectively. TGA, FTIR, and EDX showed the presence of olive organic residues in NiO-olive and their absence in NiO-pure. SEM and TEM showed an asymmetrical structure of NiO-olive and a regular, semi-spherical structure of NiO-pure. UV-Vis spectra showed surface plasmon resonance of NPs. Antiparasitic activity showed the highest mortality rate of 95% observed at a concentration of 0.06 mg/mL after four days of incubation. The antimicrobial activity showed the largest inhibition zone diameter of 33 ± 0.2 mm against the Candida albicans strain. Conclusion: Nanoparticles of NiO-olive outperformed nanoparticles of NiO-pure and olive leaf extract in both antiparasitic and antimicrobial tests. These findings imply that NiO-olive may be widely used as an eco-friendly and effective antiparasitic and disinfection of sewage.

Mycogenic Nano-Complex for Plant Growth Promotion and Bio-Control of Pythium aphanidermatum.

(1) Background: biological way is one of the most ecofriendly and safe strategies for nanomaterials synthesis. So, biosynthesis-green method was used for the preparation of Zn(II) complex (in the Nano scale) from the reaction of the schiff base ligand 2,2'-((1E,1'E)-(1,2-phenylenebis (azanylylidene)), bis(methanylylidene))bis(4-bromophenol), and Zn(II)sulphate. The biogenic ZnNP-T was characterized by different methods. Our purpose was to evaluate the ability of biosynthesis-green method for the preparation of Zn(II) complex as an antifungal agent against diseases from fungal species. (2) Methods: in this work, isolates of Pythium aphanidermatum and Trichderma longibrachiatum were obtained, and Trichderma longibrachiatum was used to prepare nano metal complex. We tested the pathogenicity of nano metal complex against seedling and germination of seeds, and we evaluated the effectiveness of ZnNP-T for growth promotion of Vicia feba in early stage and inhibitory activity against Pythium aphanidermatum. (3) Results: antagonistic activity of ZnNP-T was tested in vitro against Pythium aphanidermatum, and then the growth rates of Vicia faba were determined. The obtained data revealed that mycelial growth of pathogenic fungus was inhibited about 73.8% at 20 ppm. In addition, improved the total biomass of Vicia faba in the presence of P. aphanidermatum. All concentration of ZnNP-T positively affected root weight of Vicia faba seedlings, and positively affected shoot weight. Root and shoot lengths were affected by using 20 ppm of ZnNP-T with up to 180 and 96.5 mm of shoot and root length compared to that of the control, while germination percentage was significantly enhanced with up to 100% increase after 72 h of germination. (4) Conclusion: one of the modern challenges in vegetable or fruit production is to enhance seed germination and to grow healthy plants with strong root system. In future, there should be a focus on using of biogenic Zinc nano-complex as plant growth promoter agents.