Synthesis of strongly green-photoluminescent graphene quantum dots for drug carrier

A novel approach has been developed for the preparation of strongly green-photoluminescent graphene quantum dots (GQDs-PEG) which have been surface-passivated by polyethylene glycol. The photoluminescence (PL) quantum yield of the GQDs-PEG with 400 nm excitation was about 18.8%, which was higher than other GQDs reported in the literature. More importantly, the surface-passivated PEG on GQDs can not only enhance PL intensity but also load drug by hydrogen bonding. Moreover, the high specific surface area of GQDs-PEG endowed them high loading capability (2.5 mg/mg) to carry drug. The results demonstrated that the GQDs-PEG were suitable for drug carrier and cell imaging. [Display omitted] •A novel approach for preparing strongly fluorescent graphene quantum dots has been developed.•We first use periodic acid as an oxidant to prepare GQDs-PEG and get good results.•The photoluminescence (PL) quantum yield of the GQDs-PEG was about 18.8%.•GQDs-PEG possess high loading capability (2.5 mg/mg).