With the gradual development of carbon dots (CDs) in the antimicrobic application, efforts have been still devoted to overcome the dilemma that more effective antibacterial treatment would lead to inevitable higher cytotoxicity. In addition, their bactericidal mechanisms are still in urgent need to be clarified. Therefore, silver (copper)-containing carbon dots have been prepared via one microwave-irradiation strategy using glucose as precursors and metal salts as passivators. It was discovered that the as-prepared metal-containing CDs have the comparable or better bactericidal effect while lower cytotoxicity towards mammalian cells compared with most of corresponding commercial metal-containing antibacterial agents and their free metal ions, because of the good permeability towards bacterial cells originating from the excellent metal dispersion and glucose disguiser in/on the CDs. The minimum bactericidal concentration of silver(copper)-containing carbon dots against 1.5 (0.5) × 10 CFU/mL was less than 25 (75) μg/mL. Different bactericidal mechanisms between the two metal-containing CDs and the free copper/silver ions were revealed in details. It was found that the metal ions could directly inhibit the function of ribosomes in bacterial cells, while the metal-containing CDs showed negligible influence towards ribosome directly, instead, they inhibited bacterial metabolism through more complex pathways such as metabolic disorders, transporter inactivation or inhibition of the nucleic acid synthesis. Since the mammalians cells can switch to other pathways more flexibly than bacterial cells under the disturbance of the same metabolism pathway inhibition, the metal-containing CDs provides excellent biocompatibility.

中文翻译：

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基于含银（铜）碳点的有效抗菌且细胞毒性可忽略不计的糖衣炮弹及其机理分析

随着碳点（CD）在抗菌应用中的逐渐发展，人们仍在努力克服更有效的抗菌治疗不可避免地导致更高的细胞毒性的困境。此外，其杀菌机制仍亟待阐明。因此，使用葡萄糖作为前体和金属盐作为钝化剂，通过一种微波辐射策略制备了含银（铜）碳点。结果发现，与大多数相应的商业含金属抗菌剂及其游离金属离子相比，所制备的含金属CD具有相当或更好的杀菌效果，同时对哺乳动物细胞具有较低的细胞毒性，因为对细菌细胞具有良好的渗透性源自 CD 内/上出色的金属分散体和葡萄糖伪装剂。含银（铜）碳点对1.5（0.5）×10 CFU/mL的最低杀菌浓度小于25（75）μg/mL。详细揭示了两种含金属CD与游离铜/银离子之间不同的杀菌机制。研究发现，金属离子可以直接抑制细菌细胞内核糖体的功能，而含金属的CD对核糖体的直接影响可以忽略不计，而是通过代谢紊乱、转运蛋白失活或抑制等更复杂的途径来抑制细菌的代谢。核酸合成的过程。由于在相同代谢途径抑制的干扰下，哺乳动物细胞可以比细菌细胞更灵活地切换到其他途径，因此含金属的CD提供了优异的生物相容性。