A holistic review on red fluorescent graphene quantum dots, its synthesis, unique properties with emphasis on biomedical applications.

Graphene quantum dots (GQDs) are an evolving class of carbon-based nanomaterial, seizing tremendous attention owing to their intense optical property, engineered shapes and structures, and good photostability. Being a zero-dimensional form of carbon structure, GQDs have superior photoluminescent behavior, tunable emission and absorption, excellent biocompatibility, low cytotoxicity, hydrophilic nature, modifying surface states. Their water dispersibility and functionalized surface structure, involving heteroatoms and various functional groups onto the surface of GQDs, make them particularly suitable for biological applications.