A pH-Responsive Polycaprolactone–Copper Peroxide Composite Coating Fabricated via Suspension Flame Spraying for Antimicrobial Applications.

In this study, a pH-responsive polycaprolactone (PCL)–copper peroxide (CuO₂) composite antibacterial coating was developed by suspension flame spraying. The successful synthesis of CuO₂ nanoparticles and fabrication of the PCL-CuO₂ composite coatings were confirmed by microstructural and chemical analysis. The composite coatings were structurally homogeneous, with the chemical properties of PCL well maintained. The acidic environment was found to effectively accelerate the dissociation of CuO₂, allowing the simultaneous release of Cu²⁺ and H₂O₂. Antimicrobial tests clearly revealed the enhanced antibacterial properties of the PCL-CuO₂ composite coating against both Escherichia coli and Staphylococcus aureus under acidic conditions, with a bactericidal effect of over 99.99%. This study presents a promising approach for constructing pH-responsive antimicrobial coatings for biomedical applications. [ABSTRACT FROM AUTHOR]