Glowing Graphene Quantum Dots and Carbon Dots: Properties, Syntheses, and Biological Applications

The emerging graphene quantum dots (GQDs) and carbon dots (C‐dots) have gained tremendous attention for their enormous potentials for biomedical applications, owing to their unique and tunable photoluminescence properties, exceptional physicochemical properties, high photostability, biocompatibility, and small size. This article aims to update the latest results in this rapidly evolving field and to provide critical insights to inspire more exciting developments. We comparatively review the properties and synthesis methods of these carbon nanodots and place emphasis on their biological (both fundamental and theranostic) applications. Glowing carbon nanocrystals (graphene quantum dots and carbon dots) are emerging zero‐dimensional materials exhibiting unique and tunable photoluminescence, exceptional physicochemical properties, high photostability, biocompatibility, and molecular size. They promise a wide range of novel biological applications including bioimaging, optical biosensing, drug delivery, and theranostics.