Zinc-Schiff base ligand-confined assembly in halloysite nanotubes for antimicrobial applications

Nano-encapsulation is an efficient technology to enhance the stability and efficacy of antimicrobial agents while reducing the risks of resistance and environmental impact. In this study, novel one-dimensional halloysite nanotubes/zinc-Schiff base hybrid (CA-Zn@HNTs) was synthesized based on the ligand-confined assembly strategy. The minimum inhibitory concentration (MIC) test showed that the as-prepared CA-Zn@HNTs exhibited an MIC of 100 μg/mL against E. coli and 75 μg/mL against S. aureus . Crystal violet staining experiments showed that after treatment with CA-Zn@HNTs, the biomass of biofilms cultured for 3 days with E. coli or S. aureus ranged from 20.55 % to 23.60 %. The coating containing 5 wt% CA-Zn@HNTs achieved 99.99 % bactericidal rate within 3 h. Antibacterial adhesion experiments showed that coatings containing higher amounts of CA-Zn@HNTs were more effective in preventing biofilm formation. Furthermore, at the same loading levels, coatings aged for 7 days exhibited significantly stronger anti-bacterial adhesion effects than those aged for 3 days. This study provides an innovative strategy for developing durable, and reliable extrinsic antimicrobial materials with great potential for antimicrobial applications.