Rhodamine-based fluorescent probe for dynamic STED imaging of mitochondria.

Stimulated emission depletion (STED) microscopy holds tremendous potential and practical implications in the field of biomedicine. However, the weak anti-bleaching performance remains a major challenge limiting the application of STED fluorescent probes. Meanwhile, the main excitation wavelengths of most reported STED fluorescent probes were below 500 nm or above 600 nm, and few of them were between 500-600 nm. Herein, we developed a new tetraphenyl ethylene-functionalized rhodamine dye (TPERh) for mitochondrial dynamic cristae imaging that was rhodamine-based with an excitation wavelength of 560 nm. The TPERh probe exhibits excellent anti-bleaching properties and low saturating stimulated radiation power in mitochondrial STED super-resolution imaging. Given these outstanding properties, the TPERh probe was used to measure mitochondrial deformation, which has positive implications for the study of mitochondria-related diseases.