Preparation of Hollow N-Chloramine-Functionalized Hemispherical Silica Particles with Enhanced Efficacy against Bacteria in the Presence of Organic Load: Synthesis, Characterization, and Antibacterial Activity.

The fabrication of highly effective antimicrobial materials is an important strategy for coping with the growing concern of bacterial resistance. In this study, N-chloramine-functionalized hollow hemispherical structures were designed and prepared to examine possible enhancement of antimicrobial performance. Antimicrobial testing was carried out on Gram-negative (Escherichia coli) and Gram-positive (Baccilus Cereus) bacteria in the presence and absence of biological medium. The efficacy of the hollow hemispherical particles functionalized with various N-chloramines in killing bacteria was compared among themselves with that of small organic molecules and spherical particles to investigate the effect of the surface charge, chemical structure, and shape of the particles. Results demonstrated that quaternary ammonium salt or amine functions in the chemical structure enhanced the antimicrobial activity of the particles and made the particles more effective than the small molecules in the presence of biological medium. The importance of particle shape in the killing tests was also confirmed.