Silver (Ag) nanoparticles are effective disinfectants that offer a broad-spectrum of antibacterial activities. However, concerns about releasing Ag-based disinfectants into environment have significantly limited their large-scale applications. In this study, a facile and environmentally benign method was developed to grow Ag nanoparticles on polydopamine-functionalized Fe3O4 particles, forming a hierarchical Fe3O4-polydopamine-Ag nanocomposite. The polydopamine layer was coated on the surface of the Fe3O4 particles via self-polymerization under ambient conditions; it subsequently facilitated the formation of Ag nanoparticles from [Ag(NH3)2]+ and provided anchoring sites for the immobilization of the Ag nanoparticles. The nanocomposite presented excellent antibacterial activities against both Gram-negative (Escherichia coli) and Gram-positive(Staphylococcus aureus) bacteria, with respective minimum inhibitory concentration as 40 and 60 μg/mL, respectively. Furthermore, the nanocomposite can be separated and recovered magnetically, avoiding environmental contamination and enabling particle reuse. Recycling tests showed that over 60% of the original antibacterial activity of the particles was retained after 6 cycles of reuse.
Bibliographical noteFunding Information:
Acknowledgments: This work was supported by the National Natural Science Foundation of China (31471659 and 21636003), the Fundamental Research Funds for the Central Universities (222201514327), the International Science and Technology Cooperation Program of China (2014DFE90040), and the National Thousand Talents Program of China.
- Antibacterial materials
- Magnetic materials
- Silver nanoparticle
- Water contamination