Multifunctional Antibacterial Nanocomposites Based on Graphene Oxide, Graphitic Carbon Nitride, and Cobalt Ferrite Functionalized with an Antimicrobial Polymer Blend and Silver Nanoparticles for Biomedical and Environmental Applications

Abstract The increasing prevalence of antimicrobial resistance necessitates the development of advanced antibacterial materials. In this study, multifunctional nanocomposites based on graphene oxide (GO), graphitic carbon nitride (g-C3N4), and cobalt ferrite (SC450) were synthesized and functionalized with a polymer matrix M8 (including poly(vinyl alcohol), polyvinylpyrollidone, polyethylene glycol, and chitosan) and silver nanoparticles (Ag) to evaluate and compare their antibacterial performance across different material platforms under a consistent functionalization strategy. The successful incorporation of Ag and polymer coating was confirmed by SEM, EDS, and XRD analyses, while VSM results showed that SC450-based materials retained their magnetic properties after functionalization. Antibacterial activity was evaluated against Gram-negative bacteria, including Pseudomonas aeruginosa and Salmonella enterica. M8Ag-functionalized nanocomposites (GO and g-C3N4) exhibited enhanced antibacterial performance, achieving inhibition efficiencies exceeding 94%. The improved activity is attributed to the synergistic interaction between Ag nanoparticles, the polymer matrix, and the supporting materials, which enhances dispersion, stability, and contact with bacterial cells. These findings demonstrate the potential of polymer-functionalized nanocomposites as effective antimicrobial agents with added functionalities such as magnetic recovery, contributing to strategies for combating antibiotic resistance.