Detection of membrane biointeractions based on fluorescence superquenching

Area of Science:

• Biophysics
• Analytical Chemistry
• Materials Science

Background:

• Supported lipid bilayers (SLBs) are crucial models for cell membranes.
• Fluorescence superquenching is a sensitive detection method.
• Developing robust assays for SLB interactions is essential.

Purpose of the Study:

• To develop and validate a novel assay for detecting biointeractions with supported lipid bilayers.
• To utilize fluorescence superquenching for sensitive detection of lipid bilayer disruption.
• To demonstrate the application of this assay in flow cytometry and microfluidic formats.

Main Methods:

• Conjugated cationic polymer adsorbed onto silica microspheres, coated with anionic lipid bilayers.
• Utilized fluorescence superquenching to monitor interactions and lipid bilayer integrity.
• Employed flow cytometry and microfluidic bioassays for detection and quantitation.

Main Results:

• The lipid bilayer effectively attenuated superquenching, acting as a barrier.
• Melittin-induced lipid bilayer lysis was detected and quantified via superquenching.
• Flow cytometry demonstrated higher sensitivity for melittin detection compared to existing methods.

Conclusions:

• The superquenching assay provides a highly sensitive platform for studying molecular interactions with lipid bilayers.
• This method enables the development of functional assays for sensor applications, lipid enzymology, and molecular interaction studies.
• Proof-of-concept for microfluidic applications using superquenching to detect lipid bilayer disruption was established.