Surface-Emitting Resonator Interference Microscopy for Label-Free Monitoring of Membrane Dynamics

TL;DR

SERIM is a novel label-free microscopy technique that uses whispering gallery mode resonators to monitor cellular membrane dynamics on curved surfaces with high sensitivity and spatial resolution.

Contribution

This work introduces SERIM, a new microscopy method leveraging evanescent waves in WGM resonators for label-free, high-resolution imaging of membrane dynamics on curved substrates.

Findings

SERIM can detect subcellular membrane dynamics with diffractive limited spatial resolution.

It reveals spatial heterogeneity of membrane activity during cell migration.

SERIM responds to temperature and drug stimuli, demonstrating versatility.

Abstract

Cellular membrane dynamics play an important role in a variety of physiological processes. However, due to the stringent light-coupling conditions required for exciting evanescent waves, label-free mapping of cellular membrane dynamics on curved substrates remains challenging. Here, we report surface-emitting resonator interference microscopy (SERIM), which employs the evanescent wave naturally present in the near-field region of a whispering gallery mode (WGM) resonator to probe the subcellular membrane dynamics. The WGM resonator provides strong optical feedback for enhancing the light-mattering interaction and also provides a biomimetic curvature interface to investigate the membrane dynamics. The interaction of the evanescent wave with the cell membrane caused significant scattering, forming a highly sensitive interference pattern. We found that the time-resolved interference patterns can be utilized to extract subcellular membrane dynamics with a diffractive limited spatial resolution. We further employed the SERIM to investigate the spatial heterogeneity of membrane dynamics during migration, and also stimulus responses to temperature and drugs. In striking contrast to the conventional label-free methods, the easy excitation of the evanescent wave makes SERIM a versatile label-free strategy for studying cellular behavior on a curved surface. Our work holds promise for sensitive detection of subtle biochemical and biophysical information during cell-substrate interaction.