A comprehensive review of carbon dots for antimicrobial therapy: from design mechanisms to theranostic applications

As an emerging carbon-based nanomaterial, carbon dots (CDs) exhibit broad prospects in antimicrobial therapy owing to their unique physicochemical properties, excellent biocompatibility, and tunable multifunctional characteristics. This review systematically summarizes recent advances in the research on CDs in the antimicrobial field, including innovative construction strategies, mechanisms of action, theranostic applications, and safety evaluation. Regarding construction strategies, it highlights the design principles and antimicrobial properties of bio-derived CDs, drug molecule-directed CDs, charge-engineered CDs, metal-synergistic catalytic CDs, and amino acid-functionalized CDs. For mechanisms of action, it elaborates on the multi-target antimicrobial modes of CDs, such as physical disruption, oxidative stress induction, and metabolic interference. In terms of theranostic applications, it summarizes the innovative uses of CDs in photodynamic therapy, photothermal-photodynamic synergistic therapy, and tissue repair. Finally, it delves into safety concerns including the impacts of CDs on intestinal health, risks of metal doping, and environmental degradation behaviors. This review aims to provide theoretical guidance for the development of highly effective and safe antimicrobial CDs, while prospecting the challenges and opportunities in their clinical translation.