Yu Xiaobo, Lv Renji, Ma Zhenqiu, Liu Zhihong, Hao Yanhong, Li Qingzhang, Xu Danke
College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, China.
Analyst. 2006 Jun;131(6):745-50. doi: 10.1039/b517148b. Epub 2006 Apr 13.
Electrochemical impedance spectroscopy (EIS) combined with a gold electrode array was developed to detect multiple antibody-antigen interactions. Hepatitis B surface antigen (HBsAg), as a model sample, was employed to evaluate the characteristics of the biosensor. The array was fabricated by immobilizing antibodies on the self-assembled molecules surface of the electrodes. The surface characteristics of the array during the binding process including the antibody-antigen conjugation and the sandwich complex with HRP-labeled antibody, as well as the precipitation layer, were characterized by atomic force microscopy (AFM) and electrochemical impedance spectroscopy, respectively. A linear relationship between electron-transfer resistance and the concentrations of HBsAg ranged from 10 pg ml(-1) to 1 ng ml(-1) and the detection limit of 10 pg ml(-1) was obtained. 100 pg ml(-1) antigen samples, such as rat IgG, HBsAg and HBeAg, as well as the antigen mixture, were incubated with the relative antibody-modified electrodes on the array. No obvious cross-talk reaction was observed. All these results confirm the feasibility of applying electrochemical impedance spectroscopy to the electrode array.
开发了一种结合金电极阵列的电化学阻抗谱（EIS）来检测多种抗体-抗原相互作用。采用乙肝表面抗原（HBsAg）作为模型样本评估该生物传感器的特性。通过将抗体固定在电极的自组装分子表面来制备阵列。分别用原子力显微镜（AFM）和电化学阻抗谱对结合过程中阵列的表面特性进行表征，包括抗体-抗原结合以及与辣根过氧化物酶（HRP）标记抗体形成的夹心复合物，还有沉淀层。得到电子转移电阻与浓度范围为10 pg ml⁻¹至1 ng ml⁻¹的HBsAg之间的线性关系，检测限为10 pg ml⁻¹。将100 pg ml⁻¹的抗原样本，如大鼠IgG、HBsAg和HBeAg以及抗原混合物，与阵列上相对的抗体修饰电极孵育。未观察到明显的串扰反应。所有这些结果证实了将电化学阻抗谱应用于电极阵列的可行性。
