Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10825043 | Journal of Biochemical and Biophysical Methods | 2005 | 15 Pages |
Abstract
The quartz crystal microbalance (QCM), in combination with electrochemical impedance spectroscopy (EIS), has been utilized to monitor in situ antihuman IgG (hIgG) adsorption on bare poly(o-phenylenediamine) (PPD)- and 1-dodecanethiol (C12SH)-modified Au electrodes and succeeding human IgG reaction, respectively. The resonant frequency (f) and the motional resistance (R1) of the piezoelectric quartz crystal (PQC) as well as electrochemical impedance (EI) parameters were measured and discussed. The standard heterogeneous rate constants of the ferricyanide/ferrocyanide couple before and after the antibody adsorption and antibody-antigen reactions were determined. The results show that the amount for antibody adsorption was the greatest on the most hydrophobic (1-dodecanethiol-modified) surface, while the antibody bioactivity was almost identical on the three kinds of surfaces. Two parameters simultaneously obtained, Îf and ÎCs (interfacial capacitance), have been used for the first time to estimate both the association constant of the immunoreaction and the valence of antigen with satisfactory results. The proposed method may find wide application in interfacial biochemistry studies for its advantages in providing real-time multidimensional piezoelectric and electrochemical impedance information.
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
Hua He, Qingji Xie, Youyu Zhang, Shouzhuo Yao,