Research progress on the preparation, performance, mechanisms, and applications of carbon nanomaterials against Gram-negative bacteria.

The excessive and inappropriate use of antibiotics in clinical settings has led to bacterial mutations and the emergence of drug resistance. This escalating problem presents a major challenge in the treatment of infections, particularly those caused by Gram-negative and multidrug-resistant bacteria, for which effective therapeutic options are increasingly limited. As a result, there is an urgent need to develop novel antimicrobial agents. Recent studies have demonstrated that carbon nanomaterials, owing to their potent antibacterial activity and low susceptibility to resistance, are emerging as promising candidates in antimicrobial research. This review provides a comprehensive overview of recent advancements in the synthesis strategies, antibacterial efficacy against Gram-negative bacteria, underlying antimicrobial mechanisms, and biomedical applications of four main carbon nanomaterials (CNMs) of graphene quantum dots (GQDs), carbon dots (CDs), carbon nanotubes (CNTs), and graphene. The preparation methods and antibacterial mechanisms of CNMs with antibacterial properties are the main section. Additionally, the review addresses the current challenges hindering their clinical translation and explores potential future directions with a focus on efficacy and safety. By collating current findings, this review aims to establish a theoretical foundation for the development of innovative antimicrobial agents targeting Gram-negative bacteria.