Hybrid silica materials functionalized with chloroxine-based metal complexes: Exploring synergistic antibacterial activity

Abstract

This study presents a novel strategy for developing advanced antibacterial materials by integrating coordination compounds with silica nanoparticles. Two new coordination compounds based on chloroxine, namely, {[Ni(chloroxine)2(H2O)2]·H2O} (1) and {[Zn(chloroxine)2(H2O)]·H2O} (2), were synthesized and subsequently used to functionalize mesoporous silica (SBA-15 and MSN) to create hybrid materials: SBA-(1)-Ni, SBA-(2)-Zn, MSN-(1)-Ni, and MSN-(2)-Zn. The Zn-based hybrids exhibited exceptional luminescence, while the Ni-based counterparts displayed the expected temperature-dependent magnetic susceptibility according to the loaded Ni amount. Antibacterial assessments against Escherichia coli and Staphylococcus aureus demonstrated a remarkable enhancement—up to 200% greater efficacy than free chloroxine, while MSN-(2)-Zn achieved the most potent minimum inhibitory concentration (MIC) of 3.96 μg/mL, demonstrating their multifunctional potential. These hybrid materials not only enhance antibacterial performance at lower drug concentrations but also offer a promising approach to combat bacterial resistance by enhancing the synergistic properties of silica and coordination compounds. This work encourages further investigation of the next generation of multifunctional antimicrobial materials based on nanomaterials and metallodrugs, with superior applications in biomedicine and nanotechnology.