Antimicrobial activity and mechanisms of carbon quantum dot decorated modified zinc oxide nanoparticles against oral pathogenic bacteria

• Published in: Results in Chemistry 2024-07, Vol.9, p.101655, Article 101655
• Main Authors: Chen, Yayu, Huang, Pengcheng, Wu, Yuqiong, Liu, Chaojin
• Format: Article
• Language: English
• Subjects: Antibacterial; Carbon quantum dots; Zinc oxide
• ISSN: 2211-7156; 2211-7156
• DOI: 10.1016/j.rechem.2024.101655

[Display omitted] Caries represents one of the most prevalent bacterial infectious diseases in the oral cavity. Over decades, researchers have been actively seeking nanomaterials capable of inhibiting oral pathogenic bacteria. We utilized a one-pot hydrothermal method to synthesize CQDs with multicolor luminescence and CQD-loaded ZnO composite nanomaterials. FE-SEM revealed that the rod-like structure of CQDs/ZnO becomes finer with increased CQDs content. XRD and XPS confirmed the presence of all components within the nanocomposites. We compared the antimicrobial activities of ZnO, 7.7% and 14.3% CQDs/ZnO against Streptococcus mutans, Enterococcus faecalis, Escherichia coli, and Staphylococcus aureus. The 7.7% CQDs/ZnO composite exhibited the most effective antibacterial activity. The 7.7% CQDs/ZnO composite exhibited the most effective antibacterial activity. FE-SEM and ONPG assays demonstrated that 7.7% CQDs/ZnO disrupted the membrane structure and alters membrane permeability. ESR, DPBF and ROS assayed further confirmed that 1O2 produced by 7.7% CQDs/ZnO accumulated at the cell membrane and disrupts its structure.