Copper oxide nanoparticles (CuO NPs) were synthesized by two methods. The first was chemical method by using copper nitrate Cu (NO3)2 and NaOH, while the second was green method by using Eucalyptus camaldulensis leaves extract and Cu (NO3)2. These methods easily give a large scale production of CuO nanoparticles. X-ray diffraction pattern (XRD) reveals single phase monoclinic structure. The average crystalline size of CuO NPs was measured and used by Scherrer equation which found 44.06nm from chemical method, while the average crystalline size was found from green method was 27.2nm. The morphology analysis using atomic force microscopy showed that the grain size for CuO NPs was synthesized by chemical and green methods were 77.70 and 89.24 nm, respectively. The effectiveness of copper oxide nanoparticles on bacteria was measured for both gram positive, negative and fungi, copper oxide minutes showed excellent efficacy on biofilm formation.

The hot aqueous extract of E. camaldensis leaves as a degradable agent and copper nitrate as a copper source with cold plasma was used in this work to present an easy and green technique for copper oxide nanoparticles (CuO NPs) synthesis. UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Atomic Force Microscopes (AFM), and Scanning Electron Microscopes (SEM) were all used to determine the production of copper oxide nanoparticles (SEM). The energy gap was 4.9[Formula: see text]eV, and the average crystalline size of CuO NPs evaluated using the Scherrer equation was 15.06[Formula: see text]nm, according to the X-ray diffraction pattern (XRD). CuO NPs had a grain size of 70.63 nanometers, according to AFM morphology study. Finally, the effect of copper oxide nanoparticles on Gram-positive and Gram-negative bacteria, as well as fungi, was studied.

This work synthesizes iron oxide nanoparticles using plant extracts of Camellia sinensis, Matricaria chamomilla L., and Artemisia herba-alba Asso. and Punica granatum L. peel. with an evaluation of its antimicrobial activity. Fe2O3 nanoparticles (NPs) are highly stable and significantly affect gram-positive and gram-negative bacteria. The synthesized Fe2O3 nanoparticles were examined using X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), zeta potential (ZP), and UV–Vis spectrophotometer analysis (UV–Vis). The band gap ranged between 3.1[Formula: see text]eV and 3.8[Formula: see text]eV, which corresponds to the grain size, as its value ranged between 10.77[Formula: see text]nm and 32.31[Formula: see text]nm, that is, the smaller the grain size, the higher the band gap. On bacteria, iron oxide nanoparticles have remarkable efficacy in the formation of biofilms for gram-positive, gram-negative bacteria, and fungal.

In this work, nickel oxide nanoparticles are synthesized using plant extracts of Camellia sinensis, Matricaria chamomilla L., Artemisia herba-alba Asso. and Punica granatum L. peel., with an evaluation of their antimicrobial activity. The possible mechanism of the formation of NiO nanoparticles mediated by plant extracts has been elucidated. Synthesized green nickel oxide nanoparticles (NiO NPs) were characterized using X-ray diffraction (XRD), energy-dispersive X-ray (EDX) analysis, field emission-scanning electron microscopy (FE-SEM), UV–visible spectrophotometer analysis (UV–Vis), Fourier transform infrared spectroscopy (FTIR), and Zeta potential (ZP). The crystal size of the as-prepared NiO nanoparticles estimated via the Debye Scherrer — formula was about (19.68–23.77) nm. Nickel oxide-mediated nanoparticles possess strong antibacterial activity (gram-positive and gram-negative) and fungi.