A review on synthesis, toxicity profile and biomedical applications of graphene quantum dots (GQDs)

Graphene quantum dots (GQDs) are zero-dimensional carbon based dispersible, biocompatible, photoluminescent nanomaterials. These excellent properties make them promising candidates in various biomedical fields. Applications of GQDs in the intracellular bioimaging and its types, drug delivery along with various drug release modes, biosensing and detection strategies, therapeutic applications in various diseases and tissue engineering have been thoroughly discussed and summarized in this study. Different synthesis methods of GQDs under top-down and bottom-up approach are also described. Synthesis and biomedical applications of modified GQDs and target modified GQDs are briefly discussed. Pharmacokinetics and biodistribution of GQDs as well as the cellular internalization processes have been studied. In-vitro and in-vivo toxicity profile of GQDs along with the molecular signalling and its dependence upon various factors have been mentioned. Finally, the future prospects of research in the synthesis methods, GQD modifications, pharmacokinetics, cellular uptake, toxicity profile and biomedical applications are discussed in this study.