A novel electrochemical immunosensor for sensitive detecting toxoplasma gondii-specific IgM (Tg-IgM) was constructed based on GP-BMIMPF6 modified glassy carbon electrode (GCE) and Au-Fe3O4 nanoparticle which used for adsorbing toxoplasma gondii antigen (Tg-Ag). Cyclic voltammetry (CV) , electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) were used to study the electrochemical properties of the immunosensor. Under optimal conditions, the immunosensor can detect Tg-IgM in two linear ranges from 5×10-4-3.13×10-2 AU/mL and from 3.13×10-2-32 AU/mL with a detection limit of 2. 8X 10~4 AU/mL. The immunosensor exhibited good reproducibility, selectivity, repeatability, and stability, as well as good perform for detecting Tg-IgM in serum sample.%在玻碳电极表面修饰石墨烯-室温离子液体(GP-BMIMPF6),利用金磁纳米粒子(Au-Fe3O4)对弓形虫抗原(Tg-Ag)的高效固定,构建了用于弓形虫IgM抗体(Tg-IgM)检测的新型电化学免疫传感器.采用循环伏安法(CV)、交流阻抗法(EIS)和差分脉冲伏安法(DPV)进行电化学检测.在优化条件下,响应电流与Tg-IgM的浓度分别在5×10-4～3.13×10-2 AU/mL和3.13×10-2～32 AU/mL范围内呈线性相关,检测限为2.8×10-4 AU/mL.该传感器经外部磁场再生25次后,相对标准偏差(RSD)仅为未再生时的6.8％；血液中可能存在的干扰物对该传感器造成的检测最大偏差小于4.61％；该传感放置24天后进行检测,电流仅下降为最初的91.4％,具有良好的重复性和稳定性,可以应用于血清标本中Tg-IgM的检测.
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