Khalid Mustafa Osman Ortashi

Silver nanoparticles biogenic synthesized using an orange peel extract and their use as an anti-bacterial agent

Synthesis of nanoparticles by green methods with antibacterial properties is of great researchers’ concern in the explored of new pharmaceutical and biomedical products. In this study, we synthesized a new product of nanosized particles of silver, non-toxic economy, clean, and conservator for energy. An environmentally friendly route is used for synthesizing silver nanoparticles (AgNPs) using an orange peel extract as both reducing and stabilizing agent at room temperature. The synthesized NPs were characterized using ultraviolet (UV)-Vis spectrophotometer, Zitasizer which measures the average size of the particles at about 91 nm, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) equipped with the energy dispersive spectroscopy (EDS) and characterization using Transmission electron microscopy (TEM). The results confirmed that the orange peel extract is a very good bioreductant for the synthesis of Ag NPs and we investigated the synthesized nanoparticles as an antibacterial which showed that the biogenic synthesized AgNPs exhibit inhibition, and had significant antibacterial against both gram-positive and gram-negative bacterial strains. Key words: Silver nanoparticles, biogenic synthesis, orange peel, anti bacterial, gram-positive, gram-negative bacteria streamers.

Green synthesis, characterization, and antibacterial activity of silver/polystyrene nanocomposite

A novel, nontoxic, simple, cost-effective and ecofriendly technique was used to synthesize green silver nanoparticles (AgNPs). The AgNPs were synthesized using orange peel extract as a reducing agent for silver nitrate salt (AgNO3). The particle size distribution of AgNPs was determined by Dynamic Light Scattering (DLS). The average size of silver nanoparticles was 98.43 nm. The stable dispersion of silver nanoparticles was added slowly to polystyrene solution in toluene maintaining the temperature at 70°C. The AgNPs/polystyrene (PS) nanocomposite solution was cast in a petri dish. The silver nanoparticles encapsulated within polymer chains were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectroscopy (EDS) in addition to Transmission Electron Microscopy (TEM). The green AgNPs/PS nanocomposite film exhibited antimicrobial activity against Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae and Salmonella, and Gram-positive bacteria Staphylococcus aureus. Thus, the key findings of the work include the use of a safe and simple AgNPs/PS nanocomposite which had a marked antibacterial activity which has a potential application in food packaging.