Abstract
This review examines the design, properties, and applications of graphene quantum dots in energy, environmental, and health sectors. We discuss synthesis methodologies, highlighting the transition from zero-bandgap graphene to luminescent quantum-confined structures. The study details the integration of graphene quantum dots in photovoltaic architectures and lithium-ion batteries to improve stability and efficiency. Environmental sensing capabilities for metal ion detection are explored, emphasizing the safety of carbon-based dots over toxic heavy-metal alternatives. Biomedical applications, including bioimaging and photodynamic therapy, are evaluated with a focus on biocompatibility and renal clearance. Finally, challenges in large-scale production and commercialization are addressed.