Antibacterial activity of eco-friendly sustainable carbon dots: mechanisms, challenges, and perspectives

The processing of carbon sources as precursors for the production of eco-friendly sustainable carbon dots (CDs) has attracted attention in the literature due to the outstanding antibacterial, antioxidant, and fluorescent properties, which are associated with intrinsic high stability, biocompatibility, hydrophilicity, and low toxicity. This review summarizes the recent advances in green carbon dots using biomass waste and antibiotics as precursors. The general mechanisms associated with the antibacterial activity of CDs are discussed based on the generation/scavenging of reactive oxygen species (ROS) that results in damage of vital components/processes of the bacteria in a process that can be tuned by functionalization of the carbon core/CD's surface, allowing that photodynamic/chemodynamic processes can be activated by different excitation sources applied in the optimization of reactive oxygen species generation. Furthermore, a compilation of toxicity reports for different carbon dots is presented, highlighting the relevance of ecotoxicity, cytotoxicity, genotoxicity, and mutagenicity tests as a central topic to ensure safety for the large-scale use of green carbon dots-based products.