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.

Keywords

• immunosensors
• detection
• bioaffinity
• biodynamics
• impedance spectroscopy