Biomedical applications of Fe3O 4 -Au and Au-Fe 3 O 4 nanoparticles synthesis via a two-step pulsed laser ablation process in water

In this study, a two-step pulsed laser ablation (PLA) in water was used to create hybrid Fe 3 O₄-Au nanoparticles (NPs), utilizing a fundamental Nd: YAG laser. Various characterization methods, such as Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), were employed to analyze the properties of the hybrid NPs. FT-IR and XRD analyses successfully verified the formation of a Fe 3 O₄ NP hybrid with gold. TEM images revealed that the hybrid Fe₃O₄-Au colloid NPs formed semi-spherical nanostructures through aggregation. The antibacterial activities of hybrid NPs were also investigated using an agar-well diffusion assay against four pathogens: Pseudomonas aeruginosa ( P. aeruginosa ), Staphylococcus aureus ( S. aureus ), Streptococcus mutans ( S. mutans ), and Acinetobacter baumannii ( A. baumannii ). The results showed that hybrid NPs are more potent against both Gram-positive and Gram-negative strains of Acinetobacter baumannii , exhibiting a significant inhibition zone against the bacteria. Additionally, a hemolytic and in vitro toxicity assessment was performed to determine the compatibility of these NPs with human red blood cells (RBCs).