N-halamine functionalization of polydopamine coated Fe3O4 nanoparticles for recyclable and magnetically separable antimicrobial materials

In this report, novel recyclable antibacterial materials are developed via the functionalization of N-halamine on polydopamine-coated Fe3O4 nanoparticles. The use of Fe3O4 nanoparticles as template offers a larger surface area to antibacterial materials and makes them magnetically separable. Coating of polydopamine prevents the aggregation of Fe3O4 nanoparticles as well as introduces sites for further functionalization. Primary amine groups on the polydopamine surface are exploited to introduce the barbituric acid moiety on the surface by a simple two-step reaction. The barbituric acid moieties on the surface of the magnetic nanoparticles thereafter produce antibacterial N-halamine groups upon treatment with NaOCl. The synthesized antibacterial materials display promising antibacterial activity against both Gram-positive and Gram-negative bacteria, as measured by zone inhibition and broth microdilution methods. In the antibacterial recyclability study, it is observed that five recycle experiments do not affect the morphology and efficiency of synthesized magnetic antibacterial materials.