A method is presented to form gold-electrode-tethered lipid bilayers with exceptionally high elec. resistances. Elec. impedance spectroscopy is used to monitor the bilayer incorporation of a ligand-gated ion channel protein and the modulation of its channel activity by the selective binding of an antibody. Due to the low defect d. of the tethered membrane, the effect of a few channels can be resolved thus opening the way to single-channel expts. on this highly stable and versatile platform. In turn, a minute quantity of analyte, here antibodies, can be measured, which is of great interest for bioanalytics. [on SciFinder (R)]