Short channeled Zr-SBA-15 supporting copper-based nanoparticles: synthesis, characterization, and antibacterial activity

Abstract

Antibiotic resistance and the high infectivity of bacteria pose an increasingly threat to human health. Mesoporous silica supporting metal-based nanoparticles are considered an effective strategy to fight bacterial infections. In this work, the short channeled mesoporous Zr-SBA-15 (SBA-S) material is synthesized by sol-gel method using ZrOCl2·8H2O as an additive. Nanoparticles based on four types of copper species, Cu, Cu2O, CuO, and CuSO4, are successfully prepared, forming the Cu-loaded SBA-S materials. The composite structures are comprehensively characterized by SEM, TEM, XRD, XPS, UV–Vis DRS, FTIR, ICP, TG, and BET analysis. It turns out that all structures maintain the arrays of highly ordered pore channels, high specific surface area (SSA, ≥500 m2 g−1), and narrow width of pore size (∼7 nm). The release of Cu2+ ions shows the order is CuSO4/SBA-S > CuO/SBA-S > Cu2O/SBA-S > Cu/SBA-S. Antibacterial activity assay indicates that CuO/SBA-S shows 1.25 and 0.62 mg mL−1 of the minimum bactericidal concentration (MBC) values against E. coli and S. aureus. The acting mechanism would include the free Cu2+ ions and the nanoparticle-induced reactive oxygen species (ROS). We propose that the cheap CuO/SBA-S material would be a promising antibacterial agent with the good antibacterial activity.