Probing lipid membranes and ion channels with high frequency spectroscopy

A coplanar waveguide defined on a glass chip is integrated within a microfluidic cartridge to allow for high-frequency testing of lipid bilayer membranes. The membranes are carefully deposited on the circuit using a solvent exchange method or, alternatively, vesicle fusion. The quality of the lipid bilayer membranes is controlled by fluorescence microscopy and scanning probe techniques. The deposition of the bilayers results in a significant change in the high frequency transmission properties of the circuit. We also embed alamethicin, a model ion channel forming peptide, in the bilayers in order to quantify the influence of channel charging events on the overall impedance.