Tethered bilayer membranes as impedimetric biosensors for detection of pore-forming biological agents

Abstract

Current status of the development of impedimetric biosensors that use tethered bilayer membranes (tBLMs) as a sensing element was reviewed. To design and operate such sensors, the understanding of the nature of electrochemical impedance spectroscopy (EIS) response defined by the physical properties of tBLMs is of utmost importance. Routinely used parameters such as “membrane conductance” derived from the electric equivalent circuits cannot be regarded as the measure of activities of pore-forming agents. The reason for this is the unique molecular structure and physical properties of the submembrane reservoir as well as the dependence of measured EIS signals on the lateral 2D distribution of pores (defects) in tBLMs. The perspective way to design robust tBLM biosensors exhibiting reproducible signals relies on the possibility to control the micro-heterogeneity of tBLMs as well as to experimentally measure the specific resistance of submembrane reservoir, which defines the sensitivity of tBLM biosensors.