Electrically controlling and optically observing the membrane potential of supported lipid bilayers

Area of Science:

• Biophysics
• Surface Science
• Membrane Biology

Background:

• Supported lipid bilayers (SLBs) are crucial model systems for studying membrane proteins and cellular functions.
• Their stability and versatility allow for diverse experimental investigations.
• Existing models often lack integrated electrical and optical accessibility for dynamic studies.

Purpose of the Study:

• To develop an electrically and optically accessible platform for supported lipid bilayers.
• To demonstrate direct optical observation and electrical control of transmembrane potential in SLBs.
• To investigate the impact of electrode layers on optical probes and explore applications in membrane protein studies.

Main Methods:

• Fabrication of a supported lipid bilayer platform with integrated electrical and optical access.
• Utilizing voltage-sensitive dyes for optical probing of membrane potential.
• Employing electrochemical impedance spectroscopy (EIS) and equivalent electrical circuit modeling.
• Analyzing metal-induced energy transfer (MIET) effects on fluorescent probes.

Main Results:

• Demonstrated electrical control and optical readout of supported lipid bilayer polarization.
• Quantified membrane polarization dynamics using EIS and circuit modeling.
• Characterized MIET effects, showing adverse impact on voltage sensitivity but enabling ultrahigh axial localization accuracy.
• Established a robust platform for studying voltage-dependent membrane phenomena.

Conclusions:

• The developed SLB platform provides unprecedented electrical and optical access for membrane studies.
• MIET offers a unique tool for precise spatial localization of fluorescent probes within the membrane system.
• This platform holds significant potential for advancing research on voltage-dependent membrane proteins and surface science applications.