Formation and electrical characterization of black lipid membranes in porous filter materials

Abstract

Black lipid membranes (BLMs) are planar lipid bilayers that can be formed in porous supports such as filters. A BLM as a biomimetic membrane has important applications in, for instance, biosensing and drug-permeability assays. In the present study, BLMs were formed in the pores of three different filters to investigate their ability to support the formation of a high-quality lipid bilayer. Poly (vinylidene fluoride) (PVDF), poly(acrylonitrile) (PAN), and polypropylene/polyethylene (PP/PE) filters were utilized as filter supports, and the bilayer formation was monitored in situ by capacitance measurements. The maximum capacitance was obtained for PVDF (5.34Fcm(-2)) versus PP/PE and PAN (2.95 and 0.91Fcm(-2), respectively). Additionally, BLM leakage current measurements by wave deviation provided consistent results. Thickness and compactness of the bilayers were evaluated using pore forming protein (ClyA) insertion. The results show that PVDF with the highest porosity level was the most suitable support for BLM formation. The optimal thickness for the BLM in PVDF was 3-5nm, where the most efficient protein insertion took place, in comparison with other filters.