Comparative Analysis of Cu2O:ZnO Nanocomposites Synthesized via Green and Sol-Gel Methods for Antibiofilm and Antibacterial Activities

The increasing prevalence of antibiotic-resistant bacteria, especially in biofilm-related infections, highlights the urgent need for innovative antimicrobial materials with effective mechanisms. This study presents a comparative analysis of Cu2O-ZnO nanocomposites synthesized via two distinct methods: a green synthesis approach employing extract of Curcuma longa (turmeric) rhizomes G-Cu2O:ZnO and a sol-gel method SG-Cu2O:ZnO. The nanocomposites were evaluated there antibiofilm and antibacterial properties. The relevance of the structural, optical, and morphological studies of the obtained nanocomposites was determined using XRD, FTIR, UV-Vis spectroscopy, and FESEM-EDX analysis. The nanocomposite sample synthesized using the green method exhibited better phase purity, uniform spherical morphology, and a smaller crystallite size range compared to those synthesized by the sol-gel method. The major distinctions are structural, where green synthesis gives a simpler binary phase structure and a better oxidation state control. The nanocomposites characterized efficient bacteria killing against both Gram-positive and Gram-negative bacteria as well as effective antibacterial activity against multi-drug-resistant bacterial species. The Uv-Vis optical properties, characterized by narrow bandgaps and localized surface plasmon resonance (SPR), enhance their antibacterial capabilities. Thus, functional groups identified by FTIR spectroscopy also support their antimicrobial property.