INTRODUCTION: A novel class of biocomposite duplex systems has been engineered via a straightforward physisorption technique, enabling the immobilization of chitosan onto chemically modified carbonaceous templates. These biocomposites exhibit distinctive sorbent and antimicrobial functionalities. METHODS: Comprehensive characterization including Raman, NMR, IR spectroscopy, SEM, XRD, TGA, and BET analysis revealed tunable composite morphologies and supramolecular interactions between the substrate and chitosan, modulated by incremental doping levels. RESULTS: Sorption studies using Rose Bengal dye demonstrated effective adsorption behavior, with capacities reaching upwards of mg/g. Remarkably, water uptake exceeded 15 g/g, due to the synergistic enhancement imparted by chitosan integration. Antimicrobial and antifungal efficacy was validated through pathogen elimination assays, where low biocomposite dosages achieved complete inhibition of Escherichia coli (Gram-negative), Staphylococcus aureus (Gram-positive), and Candida albicans (fungal strain). CONCLUSION: These multifunctional biocomposites exhibit unique structure–function relationships, combining high water sorption with potent antipathogenic activity. Compared to existing materials, the biocomposites represent a versatile and diversiform platform with promising applications spanning environmental remediation and biomedical device development. The demonstrated antimicrobial and antifungal efficacy—achieving complete inhibition of Escherichia coli, Staphylococcus aureus, and Candida albicans—positions these biocomposites as strong candidates for integration into a range of biomedical applications, including wound dressings and tissue scaffolds: Their high water uptake and biocompatibility make them ideal for moist wound healing environments, while their antimicrobial properties help prevent infection, implying that this design of chitosan onto carbonaceous templates offers scalability and cost-effectiveness.