This book covers the latest advances in the field of zero-dimensional nanomaterials, with a focus on carbon quantum dots (CQDs) and graphene quantum dots (GQDs), which have attracted significant interest due to the tunable emission of CQDs and the brilliant optical and electrochemical properties of GQDs. Fundamentals, properties and synthesis methods are covered in detail, particularly photophysical and electrical properties, targeting researchers' attention on various synthesis methods and enabling them to design more useful applications. Exploring potential applications in cancer diagnosis, bioimaging, drug delivery and tissue engineering, as well as the use of materials as sensors for detecting environmental pollutants, the book provides a comprehensive reference for researchers, postgraduates and industry practitioners researching zero-dimensional carbon nanomaterials and their applications.