Broad-Spectrum Light-Activated Synergistic Antibacterial Platform Based on an Azobenzene–Quaternary Ammonium@MXene Nanocomposite

To address the global public health challenge of bacterial infections, this study developed a broadband-responsive nanoantibacterial composite material named TAB AZO-GA-MXene (TAGM). The material was prepared by electrostatically loading cationic azobenzene quaternary ammonium salts onto the surface of the two-dimensional nanomaterial MXene, with gum Arabic (GA) used as a dispersant. The antibacterial properties of the composite material exhibit distinct variations following irradiation across a broad spectrum of light, including ultraviolet, visible, and near-infrared wavelengths. TAGM combines the physical shearing and photothermal effects of MXene with the membrane-disrupting and DNA-damaging capabilities of azobenzene quaternary ammonium salts, thereby establishing a multimechanism synergistic antibacterial platform. Experimental results show that the Trans form of TAGM demonstrates stronger bactericidal activity against E. coli under green light, whereas the Cis form exhibits better inhibitory activity against S. aureus under ultraviolet light. Under corresponding illumination conditions, TAGM achieved bacterial inactivation rates of 99.11% against E. coli and 99.81% against S. aureus, indicating rapid and highly efficient antimicrobial performance. This study not only broadens the spectral response range of light-responsive antibacterial materials but also provides a strategy for developing selective, multimechanism synergistic antibacterial systems, showing promising potential for combating multidrug-resistant bacterial infections.