▎ 摘　　要

In contribution to the high interests and concerns in regards to QDs, their properties and applications, this paper presents highly photoluminescent Graphene quantum dots (GQDs) which have been prepared via a simple one-step method. They were characterized by X-ray powder diffraction (XRD), photoluminescence (PL); UV-vis diffused reflectance spectra (UV), transmission electron microscope (TEM) and scanning electron microscopy (SEM). The particle size of GQDs can be easily controlled, and these types of GQDs have tunable particle size with the average diameter of 5-7 nm. These GQDs show strong and stable photoluminescence which is dependent on excitation wavelength. It is to be noted that the GQDs can efficiently be taken up by liver cancer cells HepG2. Additionally, due to its high photostability and biocompatibility, the obtained carbon dots are demonstrated as excellent probes in cellular imaging.