Enhanced antibacterial activity of Ag nanoparticle-decorated ZnO nanorod arrays

Silver (Ag) has broad-spectrum antibacterial properties and is widely used in various fields, including in antibacterial coatings for orthopedic implants. For reasons of cost and cytotoxicity, improvement of the antibacterial efficiency of Ag is necessary. The scientific community has also shown a strong enthusiasm in this research area. In this paper, ZnO nanorod arrays were prepared on a titanium (Ti) substrate by seed-assisted hydrothermal method and Ag nanoparticles were deposited by magnetron sputtering to obtain Ag nanoparticle-decorated ZnO nanorod arrays (ZnO nanorods/Ag nanoparticles). The antibacterial properties of ZnO nanorods/Ag nanoparticles against Pseudomonas aeruginosa were systematically studied by agar diffusion method and were compared with other samples such as ZnO nanorod arrays and ZnO seed layer/Ag nanoparticles. The experimental results showed that ZnO nanorods/Ag nanoparticles displayed significantly higher antibacterial properties against Pseudomonas aeruginosa than other samples, including ZnO nanorod arrays and ZnO seed layer/Ag nanoparticles. These superior antibacterial properties originated predominantly from the morphological structure of ZnO nanorods, which optimized the particle size and distribution of Ag nanoparticles, greatly improving their antimicrobial efficiency. The synergistic antibacterial properties of Ag nanoparticles and ZnO nanorods make Ag nanoparticle-decorated ZnO nanorod arrays a promising candidate for antibacterial coating of orthopedic implants.