Facile and Large-Scale Synthesis of Graphene Quantum Dots Functionalized with Morpholine for Selective Targeting and Imaging of Lysosome

The lack of targeting selection to lysosome limits the application of graphene quantum dots (GQDs) in the diagnosis and treatment of lysosome-related disease. In this study, we developed a facile, environmentally friendly and large-scale method to prepare N-aminomorpholine (Am)-modified GQDs (Am-GQDs) via a simple hydrothermal method. The physicochemical, optical, biocompatible and targeted imaging properties were evaluated systematically. The results indicated that the synthesized Am-GQDs had a uniform size distribution and the size was around 2 nm. In addition, the synthesized Am-GQDs had excellent optical properties, fluorescent stability, and good biocompatibility. More importantly, they can selectively target and image lysosome in a relatively short coculture time with cells, demonstrating their application potential in the diagnosis and treatment of lysosomal-related diseases.