Preparation of graphene quantum dots with glycine as nitrogen source and its interaction with human serum albumin

Graphene quantum dots (GQDs) could be regarded as graphene with a lateral dimension less than 100 nm. Compared with graphene, GQDs not only possess the excellent properties of graphene but also have been proven to have low toxicity, high fluorescence stability, strong water solubility, as well as better biocompatibility. In this work, an amide bond-based, N-doped graphene quantum dot was synthesized using a simple hydrothermal method. When the reaction time was 4 h and the temperature was 180°C, fluorescence excitation and emission peaks of the product were 340 nm and 450 nm, respectively. Its interaction with human serum albumin (HSA) was investigated using spectroscopy, gel electrophoresis, and molecular simulation. Gel electrophoresis showed that the product did not cause complete scission of the peptide chain in HSA, indicating good biocompatibility. The results of molecular docking showed that the product tended to bind to site III of HSA. This paper provides a meaningful reference for design and development in nanomedicine.