Graphene, whose discovery won the 2010 Nobel Prize in physics, has been a shining star in the material
science in the past few years. Owing to its interesting electrical, optical, mechanical and chemical properties, graphene has
found potential applications in a wide range of areas, including biomedicine, photocatalysis, nanoelectronics, etc. In this
review, we summarize the latest progress of graphene in biological applications, including drug delivery, cancer therapies
and biosensing, and discuss their opportunities and challenges in this emerging field. Furthermore, the preparation and
toxicology of functionalized graphene composites are also introduced.