Bactericidal evaluation of N-halamine-functionalized silica nanoparticles based on barbituric acid

Novel N-halamine-functionalized silica nanoparticles (NHFS NPs) were facilely fabricated from the 5-allylbarbituric acid (ABBA) by a seeded copolymerization using colloidal silica nanoparticles as support and ABBA-based N-halamine copolymers as shell. The NHFS NPs with spherical morphology and legible core-shell structure have the average diameter of 538.5 nm and the average shell thickness of 19.8 nm. The NHFS NPs possessed improved antimicrobial activity against both Gram-positive and Gram-negative bacteria compared with their bulk powder counterparts. The structural effect of N-halamine on bactericidal activity was clarified through the comparison between barbituric acid-based NHFS NPs and hydantoin-structural NHFS NPs. Effects of colloidal silica support and comonomer methyl methacrylate on particles morphology and the corresponding antimicrobial activity were comparatively investigated as well. Antibacterial tests revealed that N-halamine nanomaterials originated from barbituric acid derivative displayed powerful antibacterial performance and long-term stability.