Design, synthesis and biocidal effect of novel amine N-halamine microspheres based on 2,2,6,6-tetramethyl-4-piperidinol as promising antibacterial agents

Novel superior antibiotics, i.e. amine N-halamine microspheres based on 2,2,6,6-tetramethyl-4-piperidinol, were first synthesized by the aid of the radical copolymerization for deactivating pathogenic bacteria. The effects of copolymerization period on particle size and copolymer component of the products were elucidated. The oxidative chlorine content in amine N-halamine microspheres was determined by the modified iodometric/thiosulfate technique. The effect of chlorination period on oxidative chlorine content was investigated as well. Bactericidal behaviour of the products on bacterial strain was tested by selecting Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) as model pathogenic bacteria. Antibacterial assessment, including the plate counting technique, zone of inhibition study, and antibacterial kinetic test, demonstrated that amine N-halamine microspheres exerted powerful bactericidal capability. Effects of the contacting period, particle size, and oxidative chlorine content on antimicrobial activity were also established. High stability of amine N-halamine microspheres as a function of soaking period was finally confirmed. Such a systematic investigation of amine N-halamines provides us a novel idea of making them promising candidates for deactivating bacteria and even in disease control.