▎ 摘　　要

Tuning of the electronic and surface properties of the graphene via novel strategy is highly desirable issue for the fabrication of multifunctional materials in potential sensing applications. In this study, we synthesized the extremely pure graphene nanosheets (M-GRNs) by metal intercalation approach in a bulk form, and followed by the fabrication of a portable electrochemical sensing platform prepared on screen-printed carbon electrode (SPCE). The superiority of M-GRNs in terms of the electrocatalytic performance has been confirmed by the comparison with graphene nanosheets synthesized via conventional chemical reduction route. Raman, XPS and TEM techniques were utilized to verify the structure and morphology of the prepared graphene samples. The electrochemical performance of the fabricated M-GRNs/SPCE was evaluated by various voltammetric techniques towards the anticancer agent pemetrexed (PMX) as a model target analyte. The results reveal that M-GRNs/SPCE exhibited an outstanding electrochemical performance with a linear working range of 0.05-2.2 mu M (R-2 =0.9915) and challenging detection limit of 9.7 nM towards the electm-oxidation of PMX. The detection of PMX in human serum samples was successfully analyzed at M-GRNs/SPCE with satisfactory recoveries. The possible interaction mechanism of PMX with double-stranded DNA on M-GRNs/SPCE has been also discussed. This proposed strategy could be an alternative to produce the sensitive graphene-based platforms for electro-analytical applications in clinical samples.