Synergistic Promotion System of Montmorillonite with Cu²⁺ and Benzalkonium Chloride for Efficient and Broad-Spectrum Antibacterial Activity

By intercalating montmorillonite (MMT) with Cu²⁺ and benzalkonium chloride (BAC), the present work constructed a synergistic promotion system (Cu²⁺/BAC/MMT). MMT not only enhances the thermal stability of Cu²⁺ and BAC but also facilitates the controlled release of Cu²⁺ and BAC. Concurrently, the introduction of BAC improves the material's organic compatibility. In vitro assays show that the "MIC+" of Cu²⁺/BAC/MMT against Staphylococcus aureus is merely 7.32 mg/L and 55.56 mg/L against Escherichia coli. At concentrations of 10 and 25 mg/L, Cu²⁺/BAC/MMT inactivates 100% of S. aureus and E. coli within 2 h, respectively. Furthermore, it is confirmed that the prepared Cu²⁺/BAC/MMT exhibits a long-term antibacterial ability through antibacterial experiments and release tests. Also, the biosafety of this material was also substantiated by in vitro cytotoxicity tests. These comprehensive findings indisputably portend that Cu²⁺/BAC/MMT holds promise to supplant antibiotics as an efficacious treatment modality for bacterial infections.