The preparation of chiral carbon dots and the study on their antibacterial abilities

Chirality is one of the most widespread properties in nature. After the successful application of non-optical active carbon dots (CDs) in the fields of detection, imaging, and antibacterial, the researchers turned more attention to the preparation and applications of chiral CDs. This paper reports the preparation of several chiral CDs with chiral amino acids as carbon sources through two different methods (one-step hydrothermal route and two-step coupling route), and further explores the difference in antibacterial abilities of these chiral CDs prepared by different carbon sources and synthesis methods. The experiments results showed that chiral D/LGU which are prepared through one-step method and with glutamic acid (Glu), are superior to those prepared by two-step method (NLDU/NDGU), or those prepared with cysteine as raw material (D/LCS). For D/LCS, the antibacterial ability of the L type is superior to that of the D type, proving that the synthesis method and the chirality of raw material are both important in the antibacterial behavior of prepared CDs. The chirality and optical properties of prepared CDs have been characterized by UV–vis spectrophotometer, fluorescence spectrology, and circular dichroism. Through MurA enzyme inhibition tests, SEM, and molecular docking design, the antibacterial mechanism of chiral CDs has been investigated. The research provides a sound foundation for the preparation, characterization, and application of chiral CDs, as well as the novel targeting antibacterial applications.