▎ 摘　　要

As one of the most important characteristics of nature, chirality is closely related to life activities. Therefore, chiral nanomaterials have caused great attention in material, biology and some related fields. In this paper, a new preparation method for chiral graphene quantum dots (L-GQDs and D-GQDs) was proposed via one-step hydrothermal method. This method used citric acid and L(or D)-tryptophan as raw materials to synthesize chiral graphene quantum dots. Circular dichroism spectroscopy proved that the two chiral graphene quantum dots had two chiral signals with high symmetry, and the absorption peaks were located at 230 nm and 305 nm, respectively. A lot of thermodynamic parameters have been obtained by using fluorescence. The results of viscosity measurement, DNA melting experiments and multi-spectroscopic methods indicated that there was a large chiral difference between the combination of chiral graphene quantum dots and ctDNA. UV-Vis absorption spectrometry proved that the two different chiral graphene quantum dots caused the slightly red shift of absorption peak and hypochromic effect of ctDNA. These quantum dots increased the melting temperature of DNA, but reduced the relative viscosity of ctDNA. Through hydrogen bonding and van der Waals interaction, both graphene quantum dots were inserted into the G-C base pair of ctDNA, which affected the right-handed B-form helicity of ctDNA significantly. The steric hindrance effects of L-GQDs and D-GQDs were different, resulting in the differences of them in their intercalation and binding with ctDNA. Comparably, D-GQDs with right-handedness exhibited the strongest intercalative binding ability with ctDNA, and were easier to intercalate into ctDNA with the right-handed B-helical structure, causing the significant influence on right-handed B-helical structure of ctDNA. These results revealed the molecular mechanisms of the intercalative binding interactions between chiral graphene quantum dots and DNA, which provided valuable information for the development of chiral nanomaterials in chemistry, biology, and medicine areas.