Multi-sites N-halamine antibacterial agent loaded on mesoporous silica nanoparticles with pH stimulus response

A bactericidal composite material contains a new type of N-halamine with three high bactericidal sites, and loaded the N-halamine in mesoporous silica nanoparticles (MSN), used ZnO quantum dots (ZnO QDs) as a capping gate for pH stimulus response. The N-halamine precursor NDAM was prepared by the amidation reaction of 2,5-dioxo-1,3-diazolidin-4-ylacetic acid and methacrylamide, which contains one imide and two amides NH bonds. After chlorination, three NH bonds were converted into three N-halamine sites, and the oxidative chlorine content was greatly increased. ZnO QDs have the ability to respond to pH stimuli and play a synergistic antibacterial effect with multi-site N-halamine. The antibacterial activity of MSN-AA-NDAM@ZnO nanoparticles against Gram-negative bacteria (E. coli) and Gram-positive bacteria (S. aureus) were studied by bacterial experiments. Compared with the single components (MSN-AA-NDAM-Cl and MSN@ZnO), the antibacterial activity of MSN-AA-NDAM@ZnO nanoparticles showed stronger antibacterial activity due to the synergistic bactericidal effect. This pH-responsive N-halamine bactericidal material provides a new idea in the field of antibacterial and has great application potential.