▎ 摘　　要

Graphene quantum dots (GQDs) have been widely applied in the fields of photocatalysis, bioimaging, drug delivery, metal ion detection and up-conversion photoluminescence, etc. This work introduces N-doped graphene quantum dots (N-GQDs), prepared via a one-step green wet chemical method using graphene oxide (GO) as a raw material, followed by dialysis, to create a new fluorescence sensor for rare earth elements (REEs). The obtained N-GQDs with rich oxygen functional groups showed a strong blue emission which was almost unaffected by extreme pH conditions. Due to the selective coordination to Ce4+ over other REEs, the N-GQDs can be used as a sensitive and selective chemo-sensor of Ce4+ ions in aqueous solution. The concentration range and the detection limit of the N-GQDs fluorescence probe were 1-44 mu M and 0.8352 mu M for Ce4+, respectively. The possible quenching mechanism was also explored via material characterization tools, such as FTIR, XPS, UV-vis and DLS analysis. The interference from other REEs was negligible during the quantitative determination of Ce4+. This method proved to be simple, sensitive, low cost, and also reliable for practical applications.