Alkylated glass partition allows formation of solvent-free lipid bilayer by Montal-Mueller technique

Formation of bilayer lipid membrane (BLM) by Montal-Mueller technique across a small aperture in a partition film traditionally requires coating of the aperture with a hydrophobic substance, often just an organic solvent. However, we demonstrate here that the most effective coating is not strictly hydrophobic but rather provides water/oil repellent properties. BLM were formed from diphytanoylphosphatidylcholine (DPhPC) on small 0.1-0.8 mm apertures made in specially prepared alkylated glass coverslips. The coverslips were either fluorosiliconized by 3,3,3-Trifluoropropyl-trimethoxysilane, which reduces adsorption of DPhPC in addition to creation of hydrophobic surface, or silanized, which promote adsorption of DPhPC. At fluorosiliconized surfaces stable BLM were formed. Specific capacitance of these BLM was 0.86 μF/cm2 ± 5%, while their lateral tension was estimated as 4.3 ± 0.4 mN/m. BLM were stable for hours under moderate voltage applied. At silanized surfaces stable BLM were formed only in acidic medium (3 < pH < 4), while at higher pH the membranes could cover the aperture only partially. Thus, apertures in fluorosiliconized glass can be robustly used for formation of model lipid membranes under physiological conditions.