How Probes Affect the Local Dynamics in Supercooled Liquid Revealed by Single Molecule Fluorescence Microscopy

Abstract

Due to its high sensitivity and spatial resolution, single molecule fluorescence microscopy is widely used to investigate the dynamic heterogeneity of supercooled liquids around the glass transition temperature, powerful to access microscopic information rather than the merely ensemble averaging. Plenty of works are done, provided a deeper insight into the dynamic heterogeneity of supercooled liquids. However, controversies exist when different kinds of probes are adopted for investigation, which report the local dynamics with discrepancies as a result of their diverse photophysical properties. In this review, a guidance is provided for the optical setup in wide‐field configuration and sample preparation, together with the recent progress on the photophysical properties of probes influencing the reported local dynamics, such as the probe photostability, the intermolecular interaction between probe and host matrix, covalent bonding of probe to host molecule as well as the probe size.