Humidity and cation dependency of purple membrane based biosensors

Receptor function is being investigated by incorporating naturally occurring membrane-based biological recognition elements into surface structures interfaced with microelectronic substrates. Alkylsilane molecules, formulating one half of a bilayer membrane mimetic structure, were covalently bound to the surface of Si/SiO₂ electrodes and interdigitated microsensor electrode devices. In addition to applying purple membrane patches, detergent dialysis was attempted to reconstitute lipids and bacteriorhodopsin proteins to complete the bilayer structure. Experiments are being carried out to study the humidity and cation dependency of purple membranes as reflected in capacitance measurements.