Exploring the antibacterial properties of ZnO nanorods–CuO nanoflowers: a mode of action approach

This study presents an innovative approach to enhancing the antibacterial performance of zinc oxide nanorods (ZnO NRs) by functionalizing them with copper oxide nanoflowers (CuO NFs). Initially, ZnO NRs were synthesized using a straightforward sol-gel wet chemical method, followed by the controlled integration of CuO NFs to form the desired ZnO-CuO nanocomposites (ZC NCs). Detailed physicochemical characterization tools were employed to interpret the associated structural, functional, optical, and morphological properties of the synthesized samples. X-ray diffraction (XRD) analysis was further quantitatively supported by Rietveld refinement, providing a brief account of the structural parameters and other aspects. Herein, the augmented antibacterial performance can be understood by observing the improved surface area determined by Brunauer-Emmett-Teller (BET) analysis, which shows a higher surface area of 187.622 m² g^-1 compared to bare ZnO NRs, exhibiting a high surface area-to-volume ratio that facilitates extensive contact with microbes. Notably, ZC NCs (50 wt% of CuO NFs with ZnO NRs) demonstrated significant antimicrobial activity against <i>S. aureus</i>, <i>B. cereus</i>, <i>E. coli</i>, <i>P. aeruginosa</i>, and <i>C. albicans</i>. Additionally, the mode of action study revealed that the antimicrobial performance is primarily attributed to the generation of reactive oxygen species (ROS) and the disruption of the microbial cell membrane. These dual-functional ZC NCs demonstrate significant potential in healthcare applications, providing a cost-effective and scalable solution for developing advanced antibacterial and antifungal agents.