Optical Antenna-based Fluorescence Correlation Spectroscopy to Probe the Nanoscale Dynamics of Biological Membranes

TL;DR

This paper discusses the integration of optical antennas with fluorescence correlation spectroscopy to achieve nanometer spatial and microsecond temporal resolution for studying nanoscale membrane dynamics.

Contribution

It presents recent advances in combining optical antennas with FCS to probe the rapid, nanoscale organization of biological membranes, surpassing traditional microscopy limits.

Findings

Enhanced spatial resolution down to nanometers

Microsecond temporal resolution achieved in membrane studies

Potential to investigate lipid rafts and nano-assemblies

Abstract

The plasma membrane of living cells is compartmentalized at multiple spatial scales ranging from the nano- to the meso-scale. This non-random organization is crucial for a large number of cellular functions. At the nanoscale, cell membranes organize into dynamic nano-assemblies enriched by cholesterol, sphingolipids and certain types of proteins. Investigating these nano-assemblies known as lipid rafts is of paramount interest in fundamental cell biology. However, this goal requires simultaneous nanometer spatial precision and microsecond temporal resolution which is beyond the reach of common microscopes. Optical antennas based on metallic nanostructures efficiently enhance and confine light into nanometer dimensions, breaching the diffraction limit of light. In this Perspective, we discuss recent progress combining optical antennas with fluorescence correlation spectroscopy (FCS) to monitor microsecond dynamics at nanoscale spatial dimensions. These new developments offer numerous opportunities to investigate lipid and protein dynamics in both mimetic and native biological membranes.