An electrochemical impedance immunosensor with signal amplification based on Au-colloid labeled antibody complex

作者：Chen, Huan; Jiang, Jian Hui; Huang, Yong; Deng, Ting; Li, Ji Shan; Shen, Guo Li; Yu, Ru Qin^*

来源：Sensors and Actuators B: Chemical , 2006, 117(1): 211-218.

DOI：10.1016/j.snb.2005.11.026

• immunosensor
• electrochemical impedance spectroscopy (EIS)
• signal amplification
• Au-colloid labeled antibody complex

A highly sensitive electrochemical impedance immunosensor was developed by using a novel amplification procedure with the application of a Au-colloid labeled antibody as the primary amplifying probe and a multistep amplification by alternating treatment of the resulting assembly with a Au-colloid labeled secondary antibody and a Au-colloid labeled antibody. The rabbit anti-human IgG antibody was immobilized through a selfassembled colloidal An layer on the gold electrode. The analyte, human IgG, was detected through the impedance measurements with the sensing interface modified by the rabbit anti-human IgG antibody. In the primary amplification, the An-colloid labeled goat anti-human IgG antibody was used to amplify the electron-transfer resistance resulting from the binding of the antigen to the immunosensor surface. A further amplification was performed through sequential binding of the Au-colloid labeled rabbit anti-goat IgG antibody and the Au-colloid labeled goat anti-human IgG antibody. The impedance increments were observed to be linearly dependent upon the IgG concentration in the range of 15.3-328.3 ng L-1 with a detection limit of 4.1 ng L-1.

• 出版日期2006-9-12
• 单位湖南大学