High impedance droplet-solid interface lipid bilayer membranes

A droplet-solid interface lipid bilayer membrane (DSLM) with high impedance was developed through controlling the contact area between an aqueous droplet and electrode. The electrode size can be easily controlled from millimeter to micrometer level. The droplet-solid interface lipid bilayer membranes were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and fluorescence microscopy. The fluorescence recovery after photobleaching (FRAP) was applied to determine the diffusion coefficient of egg PC DSLM to be 2.58 μm² s^-1. The DSLM resistance can reach up to 26.3 Gω, which was then used to study the ion channel behavior of melittin. The resistivity of the bilayer membrane decreased linearly with the increase of melittin concentration in the membrane. The high impedance and fluidity of DSLM makes it an ideal model cell membrane system for ion channel study and high-throughput drug screening.