Graphene-Induced Energy Transfer for Quantitative Membrane Biophysics at Sub-Nanometer Resolution

TL;DR

This paper demonstrates that graphene-induced energy transfer (GIET) microscopy can precisely measure nanoscale changes in membrane thickness caused by cholesterol in lipid bilayers, advancing membrane biophysics research.

Contribution

The study applies GIET to quantify cholesterol-induced membrane thickness variations, showcasing its high sensitivity for nanoscale structural analysis of bio-membranes.

Findings

GIET accurately detects nanometric membrane thickness changes.

Cholesterol increases membrane thickness in supported lipid bilayers.

GIET is a powerful tool for studying membrane structural dynamics.

Abstract

Graphene-induced energy transfer (GIET) is a recently developed fluorescence-spectroscopic technique that achieves sub-nanometric optical localization of fluorophores along the optical axis of a microscope. GIET is based on the near-field energy transfer from an optically excited fluorescent molecule to a single sheet of graphene. It has been successfully used for estimating inter-leaflet distances of single lipid bilayers, and for investigating the membrane organization of living mitochondria. In this study, we use GIET to measure the cholesterol-induced subtle changes of membrane thickness at the nanoscale. We quantify membrane thickness variations in supported lipid bilayers (SLBs) as a function of lipid composition and increasing cholesterol content. Our findings demonstrate that GIET is an extremely sensitive tool for investigating nanometric structural changes in bio-membranes.