The unique properties of zinc oxide nanoparticles (ZnO-NPs) produced using plant extract make them attractive for use in medical as well as industrial applications, and it is necessary to develop environmentally friendly methods for their synthesis. This can be accomplished by replacing the traditional chemical compounds for the reduction of the zinc ions to ZnO-NPs during synthesis with natural plant extracts. Here, the biosynthesis of ZnO-NPs using Punica granatum (P. granatum) fruit peels extract was investigated as the reducing and stabilizing agent. The P. granatum/ZnO-NPs with spherical and hexagonal shapes were biosynthesized at different annealing temperatures. The X-ray diffraction analysis confirmed the synthesis of highly pure ZnO-NPs with increasing crystallinity in higher annealing temperatures. The ZnO-NPs displayed characteristic absorption peaks between 370 and 378 nm in the UV evis spectra. Transmission electron microscopy (TEM) imaging showed the formation of mostly spherical and hexagonal-shaped ZnO-NPs in the mean size of 32.98 nm and 81.84 nm at 600 C and 700 C respectively. According to FTIR spectrum, strong absorption bands in the range of 462e487 cm À1 corresponding to ZneO bond stretching can be seen. Antibacterial activities of P. granatum/ZnO-NPs against Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) were investigated and compared. Results obtained show that smaller-sized P. granatum/ZnO-NPs are more effective in inhibiting growth of both bacteria. In addition, cytotoxicity assays were performed for P. granatum/ZnO-NPs against human colon normal and cancerous cells. P. granatum/ZnO-NPs exhibited similar killing activities of both cell lines at the concentration of !31.25 mg/mL. The biosynthesized ZnO-NPs could offer potential applications in biomedical field.

In this study, a comparative study of effect using honey on copper nanoparticles (Cu-NPs) via simple, environmentally friendly process and inexpensive route was reported. Honey and ascorbic acid act as stabilizing and reducing agents with the assistance of sonochemical method. The products were characterized using UV-visible (UV-vis) spectroscopy, X-Ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), Field-Emission Scanning Electron Microscopy (FESEM) and Fourier Transform Infrared (FTIR) spectroscopy. The reddish brown colour demonstrated the formation of Cu-NPs and UV-visible proved the plasmon resonance of Cu-NPs. XRD also confirmed a highly pure Cu-NPs obtained with absence of copper oxide in which the structure is crystalline. The spherical size of the Cu-NPs was acquire in the presence of honey which is 3.68 ± 0.78 nm with narrow particle distribution. The antibacterial activity was seen against gram-positive and gram-negative bacteria which are Enterococcus faecalis (E. faecalis) and Escherichia coli (E. coli). At higher concentration of Cu-NPs, they were more effective in killing both bacteria. The Cu-NPs without and with honey exhibited toxicities toward normal and cancerous cells. However, Cu-NPs without honey showed more potent killing activity against normal and cancer cells.

Photocatalytic activity of ZnO-NPs was tested by degradation of Malachite Green dye under UV light irradiation. The ZnO-NPs were biosynthesized using Punica granatum (pomegranate) fruit peels extract as the stabilizing agent. Simple sol-gel method and calcination in different temperatures (400, 500, 600 and 700°C) were carried out to obtain pure ZnO-NPs with high photocatalytic properties. In the degradation studies, 20 mg ZnO-NPs were used to degrade Malachite Green dye of 10 ppm initial concentration for a total period of 50 minutes in a 100 ml reaction volume. Results obtained shown that ZnO-NPs calcined in 700°C had the highest removal efficiency at about 99% in 40 minutes. This proves that biosynthesized ZnO-NPs have a high potential to be used as a photocatalyst to degrade textile dyes in a short time for wastewater treatments.

The combination of graphene-based materials and inorganic nanoparticles for the enhancement of the nanomaterial properties is extensively explored nowadays. In the present work, we used a sonochemical method to synthesize a copper/reduced graphene oxide (Cu/RGO) nanocomposite using Australian honey and vitamin C as capping and reducing agents, respectively. The honey-mediated copper/reduced graphene oxide (H/Cu/RGO) nanocomposite was then characterized through UV-visible, XRD, HRTEM, and FTIR analysis. The copper nanoparticles (Cu-NPs) in the nanocomposite formed uniform spherical shapes with a size of 2.20 ± 0.70 nm, which attached to the reduced graphene oxide (RGO) layers. The nanocomposite could suppress bacterial growth in both types of bacteria strains. However, in this study, the nanocomposite exhibited good bactericidal activity toward the Gram-positive bacteria than the Gram-negative bacteria. It also showed a cytotoxic effect on the cancer colorectal cell line HCT11, even in low concentrations. These results suggested that the H/Cu/RGO nanocomposite can be a suitable component for biomedical applications.

Chitosan nanoparticles (ChNPs) have been extensively examined for various biomedical applications due to their advantages include large surface area, biodegradability, and biocompatibility. The purpose of this research was to synthesize ChNPs using a simple ionic gelation technique by the interaction of low molecular weight chitosan (LMWC) and sodium tripolyphosphate (TPP) as a cross-linking agent. ChNPs, TPP, and LMWC were analysed by X-ray diffraction (XRD) and Fourier transforms infrared (FTIR) spectra that indicated the formation of ChNPs, attributing to the rearrangement of the nanoparticles after adding the TPP cross-linker into the LMWC solution. XRD analysis exhibited that ChNPs were amorphous, due to the effect of TPP cross-linker. Dynamic light scattering showed the nano-dimension of ChNPs with a hydrodynamic size of 68.50 nm. Thus, the obtained results indicated that the properties of chitosan were improved through converting it into nanoparticles using TPP initiated ionic gelation procedure.