A critical review on antibacterial mechanisms of carbon dots: a comprehensive approach to combating multidrug resistance

Abstract

The emergence of multidrug-resistant (MDR) bacteria poses a significant challenge to global healthcare, requiring innovative antibacterial approaches. Carbon dots (CDs), a type of zero-dimensional nanomaterial, are promising antibacterial agents due to their distinctive physicochemical features, including excellent stability, biocompatibility, and variable surface functionalities. This review critically examines the antibacterial mechanisms of CDs. CDs exert antibacterial activity by compromising bacterial membranes via electrostatic interactions, inducing oxidative stress via reactive oxygen species (ROS) generation, and disrupting essential cellular functions, including enzyme activity, gene expression, and quorum sensing (QS). Furthermore, doping techniques improve the antibacterial activity of CDs by altering their charge and interaction dynamics. Selective heteroatom doping further strengthened the antibacterial efficacy of carbon dots. Nitrogen doping improves electrostatic membrane interactions but often necessitates elevated inhibitory levels. Conversely, individual metal dopants, such as manganese and zinc, exhibit enhanced antibacterial efficacy at lower MIC values by facilitating ROS production and membrane disruption. Co-doped systems that integrate nitrogen with metals achieve optimal performance, with the lowest MIC ranges resulting from combinatorial enhancements in surface charge interactions and oxidative stress processes. The suppression of biofilm creation and metabolic processes improves their antibacterial properties. Despite their enormous promise, refining CDs to improve selectivity, effectiveness, and biocompatibility remains a critical challenge. Future research should focus on optimizing synthesis techniques and understanding the long-term biological consequences, including CDs in vivo distribution across organs, renal elimination efficacy, and their ability to elicit immunological responses. Studying the pharmacokinetics and immunologic characteristics is critical for effective clinical implementation.

Graphical abstract

The alternative text for this image may have been generated using AI.