Antibiofilm efficacy of a green graphene oxide-silver nanocomposite against mixed microbial species biofilms: an in vitro and in silico approach

Abstract

Biofilm-related infections contribute to 65–80% of all human microbial infections, leading to significant global mortality and morbidity. In addition to their medical impact, biofilms pose serious challenges in non-medical sectors such as industrial water systems, food processing, and marine infrastructure, leading to fouling, clogging, and contamination. In this study, a biologically synthesized, non-toxic and eco-friendly reduced graphene oxide-silver nanocomposite (rGO/AgNPs) was applied to prevent microbial biofilm formation. The nanocomposite demonstrated potent antimicrobial and antibiofilm activities against single and mixed bacterial and fungal species such as Gram-positive bacteria (Staphylococcus aureus and Streptococcus mutans), Gram-negative bacteria (Pseudomonas aeruginosa), and a fungal species (Candida albicans). Crystal violet assays and scanning electron microscopy confirmed a significant reduction (50–70%) in biofilm biomass. Molecular docking studies further demonstrated robust binding of AgNPs to biofilm-associated proteins, supporting their mechanism of action. These findings demonstrate the potential of green rGO/AgNPs nanocomposites for broad-spectrum antibiofilm applications in both clinical and industrial settings, offering a sustainable strategy for future antimicrobial material development.