2022 - A chip-based array for high-resolution fluorescence characterization of free-standing horizontal lipid membranes under voltage clamp
Orbit mini OPTO-INV Publication in Lab on a Chip (2022)
Ensslen T., Behrends J.C.
Orbit mini OPTO-INV Publication in Lab on a Chip (2022) doi:10.1039/D2LC00357K
Optical techniques, such as fluorescence microscopy, are of great value in characterizing the structural dynamics of membranes and membrane proteins. A particular challenge is to combine high-resolution optical measurements with high-resolution voltage clamp electrical recordings providing direct information on e.g. single ion channel gating and/or membrane capacitance. Here, we report on a novel chip-based array device which facilitates optical access with water or oil-immersion objectives of high numerical aperture to horizontal free-standing lipid membranes while controlling membrane voltage and recording currents using micropatterned Ag/AgCl-electrodes. We demonstrate both wide-field and confocal imaging, as well as time-resolved single photon counting on free-standing membranes spanning sub-picoliter cavities are demonstrated while electrical signals, including single channel activity, are simultaneously acquired. This optically addressable microelectrode cavity array will allow combined electrical-optical studies of membranes and membrane proteins to be performed as a routine experiment.