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化学学报
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化学学报 ›› 2012, Vol. 70 ›› Issue (19): 2085-2090.DOI: 10.6023/A12050257 上一篇    下一篇

研究论文

基于石墨烯及CeO2-Au的一次性弓形虫IgM抗体免疫传感器

蒋姝婷a, 陈中平b, 刁奇智a, 盛尚春a, 谢国明a, 张名均b, 徐华建a   

  1. a 重庆医科大学检验医学院 临床检验诊断学教育部重点实验室 重庆 400016;
    b 重庆市九龙坡区第一人民医院 检验科 重庆 400050
  • 投稿日期:2012-05-30 发布日期:2012-07-30
  • 通讯作者: 谢国明 E-mail:guomingxie@cqmu.edu.cn
  • 基金资助:
    项目受重庆市自然科学基金(No. CSTC, 2010BB5356);重庆市九龙坡区科委科技项目(No. 2011009)和重庆医科大学临床检验诊断学国家重点学科基金(No. 2010102)资助.

Disposable Amperometric Immunosensor for Detecting Toxoplasma Gondii-Specific IgM Based on Graphene and CeO2-Au

Jiang Shutinga, Chen Zhongpingb, Diao Qizhia, Sheng Shangchuna, Xie Guominga, Zhang Mingjunb, Xu Huajiana   

  1. a Key Laboratory of Medical Diagnostics of Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China;
    b The First People’s Hospital of Jiulongpo District in Chongqing, Inspection Department, Chongqing 400050, China
  • Received:2012-05-30 Published:2012-07-30
  • Supported by:
    Project supported by the Natural Science Foundation of Chongqing (CSTC, 2010BB5356), The Science and Technology Project of Jiulongpo District Committee in Chongqing (2011009) and Foundation of National Key Discipline in Laboratory Medicine of Chongqing Medical University (2010102).

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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7.5×10-4～24 AU·mL-1的范围内呈线性相关, 检测限为4.4×10-4 AU·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.

关键词: 弓形虫IgM抗体, 石墨烯, CeO2-Au, 丝网印刷碳电极, 免疫传感器

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-Au 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 CeO2-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.

Key words: toxoplasma gondii-specific IgM, graphene, CeO2-Au, screen-printed carbon electrode, immunosensor