Graphene has a unique planar structure, as well as excellent electronic properties, and has attracted a great deal of interest from scientists. Graphene and its derivatives display advantageous characteristics as a biosensing platform due to their high surface area, good biocompatibility and ease of functionalization. Moreover, graphene and its derivatives exhibit excellent optical properties; thus they are considered to be promising and attractive candidates for bioimaging, mainly of cells and tissues. Following an introduction and a discussion of the optical properties of graphene, this review assesses the methods for engineering the functions of graphene and its derivatives. Specific examples are given on the use of graphene and its derivatives in fluorescence bioimaging, surface-enhanced Raman scattering (SERS) imaging, and magnetic resonance imaging (MRI). Finally, the prospects and further developments in this exciting field of graphene-based materials are suggested.