Impedance spectroscopy in biodynamics: Detection of specific cells (pathogens) using immune coated electrodes
Eugen Gheorghiu, Daniel Andreescu, Mariana Oporanu, Mihaela Gheorghiu, Sorin Cazacu, Corina Balut, and Alexandru Ursu
pp. 791 - 797
Abstract
We describe the theoretical and experimental approaches for monitoring the interfacial biomolecular reaction between immobilized antibody and the antigen binding partner (the analyte, or the targeted cell) using Impedance Spectroscopy, IS. The key idea is to reveal the presence of the analyte by investigating the dynamics of the impedance changes at the interface between transducer and bulk during the process of antibody-antigen binding (coupling of specific compounds to sensor surface). In this work, antibody-antigen (Ab-Ag) reaction was directly monitored using an impedance analyzer capable of ~ 1 measurement/second and covalent immobilization chemistry and modified electrodes in the absence of a redox probe. The proposed approach may be applicable to monitoring other surface interfacial reactions such as protein-protein interactions, DNA-DNA interactions, DNA-protein interactions and DNA-small molecule interactions.