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在丝网印刷碳电极（SPCE）表面修饰石墨烯－壳聚糖（GPCS）复合膜和CeO2－Au纳米粒子，利用CeO2-Au纳米粒子对弓形虫特异性抗原（Tg—Ag）的固定，构建了用于弓形虫IgM抗体（Tg—IgM）检测的一次性电流型免疫传感器．采用扫描电镜（SEM）和透射电镜（TEM）对该免疫传感器的修饰进行表征，利用循环伏安法（Cv）、交流阻抗法（EIS）和差分脉冲伏安法（DPV）进行电化学性能检测．响应电流与Tg—IgM的浓度在7．5×10^-4～24AU·mL^-1的范围内呈线性相关，检测限为4．4×10^-4AU·mL^-1．该免疫传感器具有良好的灵敏度、特异性、稳定性和重复性．与ELISA方法相比，该方法结果可靠，孵育时间短，可用于临床上Tg—IgM的检测．“,”Toxoplasma gondii-specific IgM (Tg-IgM) is a sensitive and reliable marker for early diagnosing toxoplasmosis infection in pregnant women. In this study, a disposable amperometric immunosensor for sensitive detecting Tg-IgM was constructed based on graphene (GP) and CeO2-Au nanoparticle. The GP was treated with chitosan (CS) to obtain a stable graphene-chitosan (GPCS) composite membrane. The CeO2-An nanoparticle which was used for the preparation of the amperometric immunosensor was synthesized by the hydrothermal method. GPCS composite membrane was first assembled onto the screen-printed carbon electrode (SPCE) for adsorbing the CeOE-AU nanoparticle. The toxoplasma gondii antigen (Tg-Ag) was subsequently adsorbed by CeO2-Au nanoparticle to obtain the proposed immunosensor. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed to characterize the construction process of the immunosensor. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) were used to study the electrochemical properties of the immunosensor. The results indicated that, CS employed in this study improved the dispersion and homogeneity of GP, as well as enhance the stability of the proposed immunosensor. The use of GPCS composite membrane and CeO2-Au nanoparticle had good conductivity and prominent biocompatibility, which excellently improved the sensitivity of the immunosensor. In the optimal conditions, the proposed immunosensor can be applied to quantify the concentration of Tg-IgM in a wide linear range from 7.5 × 10^-4 AU·mL^-1 to 24 AU·mL^-1 with a correlation coefficient of -0.998 and a low detection limit of 4.4× 10^-4 AU·mL^-1 (S/N=3). The novel proposed immunosensor for detecting Tg-IgM in human serum specimens with satisfactory results had also been proved. In addition, the Tg-IgM contents determined by the immunosensor agreed well with the ELISA measurement. Furthermore, the proposed amperometric immunosensor exhibited some advantages, such as high selectivity, long-term stability, good repeatability, low sample consumable, and short analysis time, which were suitable for detecting toxoplasma infection in pregnant women.