Agar Working Electrode as a Support for Bilayer Lipid Membrane: Effects of Direct Current Bias Voltages

Abstract

The agar working electrode as a hydrogel support for bilayer lipid membranes (BLM) was studied by electrochemical impedance spectroscopy. The aim was to study the influence of dc bias voltage on the formation of a stable supported bilayer lipid membrane (s-BLM) on the electrode tip. It was concluded that the hydrogel support is sufficiently stable in the applied range of bias voltages. The agar electrode provides satisfactory results in the frequency range 1–1?10⁴ Hz. The electrode properties suggest applicability in deposition of s-BLM. Electric properties of s-BLM significantly depend on the dc bias voltage. The specific membrane capacitance of s-BLM at –0.4 V was comparable with that of a conventional planar BLM. However, a shift to negative bias voltages led to a significant change of membrane resistance, possibly due to the increasing number of pores or defective structures in the lipid bilayer.