Nanoparticles of gold with zinc oxide (Au@ZnO NPs) were prepared by laser ablation and then capped with curcumin nanoparticles (Cur-Au@ZnO NPs). The synthesized NPs were characterized using different techniques, including transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), UV-visible spectroscopy, and X-ray diffraction. In addition, the ability of NPs as a promising antibacterial agent was tested against Staphylococcus aureus through the agar well diffusion method and AO/EtBr staining assay. The results showed that the prepared nanoparticles (Cur-Au@ZnO) served as an antibacterial agent and can destroy the bacterial cells by losing the cell wall integrity and penetrating the cytoplasmic membrane. Moreover, the findings confirmed the role of the formed NPs in attenuation of the adherence and invasion of S. aureus to rat embryonic fibroblast (REF) cells. Furthermore, the activity of Cur-Au@ZnO NPs against the S. aureus α-hemolysin toxin was evaluated using the western blot technique, using human alveolar epithelial cells (A549), and through histopathology examination in a mouse model. In conclusion, the built Cur-Au@ZnO NPs can be used as a potential antibacterial agent and an inhibitor of α-hemolysin toxin secreted by S. aureus. These NPs may offer a new strategy in combating pathogen infections and in the future for biomedical and pharmaceutical applications.

No abstract

The preparation of Au-ZnO nanocomposite involves the synthesis of Au and ZnO colloidal solutions by Nd:YAG laser (1064nm) ablation of metal targets in deionized water followed by laser irradiation of the mixed colloidal solution by a second harmonic Nd:YAG laser (532nm). The UV-visible show the gold nanoparticle (NPs) peak at 525nm while the peak of the ZnO nanoparticle (NPs) at 375nm. The Au-ZnO nanocomposite showed a blue shift in the absorption of the ZnO excited, while due to the plasomon resonance and interfacial charge transfer of Au NPs lead to redshift in the absorption, also show the intensity absorpation increases with the concentration of the metal nanoparticles. The morphological properties of nanoparticles have been characterized by Transmission Electron Microscopy (TEM).

No abstract

This study presents a comprehensive look into the potential therapeutic, antibacterial, and anticancer properties of a nanocomposite (NC) of gold (Au) and zinc oxide (ZnO). In this study, we analyzed the adherence between Au nanoparticles (NPs) and ZnO NPs. X-ray diffraction analysis showed high crystallinity and small crystallite sizes of Au NPs and ZnO NPs, while transmission electron microscopy showed spherical NPs. Furthermore, histogram analysis showed that the average particle size of Au NPs is 27 nm, while that of ZnO NPs is 35 nm. The adherence of ZnO NPs on the surface of Au NPs increased their combined particle size to 51 nm and revealed a high-population core-shell structure. The activity of Au/ZnO NCs against Escherichia coli was more potent when compared to that of elemental Au and ZnO NPs alone. The cytotoxic effects of Au NPs, ZnO NPs, and Au/ZnO NCs against human breast cancer cells (AMG13) and human esophageal adenocarcinoma cancer cells (SK-GT4) were investigated in this study. We found that AMG13 is more sensitive than SK-GT4 to the activity of Au/ZnO NCs. The cytotoxicity of Au/ZnO NCs against AMG13 was 89%, while that against SK-GT4 was 85%. Less cytotoxic effects were recorded against normal cells (MCF7) when compared with those of cancer cells. Based on these findings, the synthesized Au/ZnO NCs could be used as a promising strategy for biomedical applications.