Mentha suaveolens Leaves Extract-Mediated Synthesis of CoO@TiO₂ and Fe₂O₃@TiO₂ Core/Shell Nanoparticles with Synergistic Antimicrobial and Antioxidant Activities

This study reports the green synthesis of biocompatible TiO₂-based nanoparticles using Mentha suaveolens extract as a reducing and capping agent. We successfully produced two novel nanocomposites: Fe₂O₃@TiO₂ and CoO@TiO₂. These nanocomposites possess distinct optical properties, enhanced surface area, and well-defined morphologies, as revealed by advanced characterization techniques. Notably, Fe₂O₃@TiO₂ exhibits a red-shifted absorption, suggesting potential for photocatalysis, sensing, or light-harvesting applications. Furthermore, the nanocomposites displayed improved antibacterial activity against various bacterial strains compared to the M. suaveolens extract, highlighting their potential as effective and biocompatible antimicrobial agents. Our work pioneers a sustainable and one-step approach for synthesizing versatile TiO₂-based nanocomposites with tunable functionalities. These findings open doors for developing novel materials with applications ranging from enhanced antimicrobial defenses to light-driven technologies.