Title: Green-Synthesized Chitosan–MXene–Silver Nanocomposite: A Synergistic Antimicrobial Platform from Agro-Industrial Waste
Abstract:
We report a novel, multifunctional antimicrobial nanocomposite engineered via a green route from agro-industrial shrimp shell waste, integrating chitosan, in situ synthesized silver nanoparticles (AgNPs), and exfoliated Ti?C?T? MXene. To the best of our knowledge, this is among the first reports to synergistically combine these three components into a single bio-derived platform, achieving potent antibacterial efficacy at ultra-low silver content (<1 µg/mL). Chitosan was extracted through eco-friendly processing and served both as a stabilizing matrix and reducing agent for AgNPs (~15 nm), while monolayer MXene sheets (~1.3 nm thick) provided sharp-edged, redox-active surfaces. Comprehensive characterization by UV–Vis, FTIR, XRD, XPS, SEM, and AFM confirmed the structural integrity and homogeneity of the nanocomposite. The material exhibited strong bactericidal action against Escherichia coli and Staphylococcus aureus, with minimum inhibitory concentrations (MICs) of 50 µg/mL and 52.3 µg/mL, respectively—substantially lower than those of individual components (100–200 µg/mL). Mechanistic validation through NBT-based ROS assays, fluorescence live/dead imaging, and SEM confirmed a multimodal killing mechanism involving oxidative stress, membrane disruption, and ionic interference. This sustainable nanocomposite leverages waste-to-wealth conversion with translational potential in antimicrobial coatings, wound dressings, and water purification. Its ultralow silver requirement offers a safer, cost-effective alternative to traditional nanomaterials, supporting its promise as a next-generation antimicrobial platform.
