Accurate distinguish of cancer cells through fluorescence plays an important role in cancer diagnosis. Here we synthesized a blue fluorescent nitrogen-doped graphene quantum dots (N-GQDs) from citric acid and diethylamine via one-step hydrothermal synthesis method which was simple and quick to avoid by-products, and highlighted the binding sites to achieve precise combination. Due to the nitrogen element doping, amide II bond was amply obtained and abundant binding sites were provided for hyaluronic acid (HA) conjugation. N-GQDs solution with different pH value was then conjugated to HA via an amide bond for the recognition of human breast cancer cells (MCF-7 cells), and the formation of amide bond was more favorable under alkaline conditions. HA conjugated N-GQDs (HA-N-GQDs) were combined with CD44 which was over expressed on the surface of MCF-7 cells, resulting in MCF-7 cells performing stronger fluorescence. HA-N-GQDs showed high fluorescence, low toxicity, and good cytocompatibility, which held it play a role in fluorescence imaging for accurate identification of cancer cells.

通过荧光准确区分癌细胞在癌症诊断中起着重要作用。在这里，我们以柠檬酸和二乙胺为原料，通过一步水热合成方法合成了蓝色荧光氮掺杂石墨烯量子点（N-GQDs），该方法简单快捷，避免了副产物的产生，并突出了结合位点以实现精确结合。由于氮元素掺杂，大量获得了酰胺 II 键，并为透明质酸 (HA) 缀合提供了丰富的结合位点。然后将不同pH值的N-GQDs溶液通过酰胺键与HA结合用于人乳腺癌细胞（MCF-7细胞）的识别，在碱性条件下酰胺键的形成更有利。HA缀合的N-GQDs (HA-N-GQDs)与在MCF-7细胞表面过表达的CD44结合，使MCF-7细胞表现出更强的荧光。HA-N-GQDs表现出高荧光、低毒性和良好的细胞相容性，使其在荧光成像中发挥作用，以准确识别癌细胞。