An Endoplasmic Reticulum-Targeted Ratiometric Fluorescent Molecule Reveals Zn Micro-Dynamics During Drug-Induced Organelle Ionic Disorder.

The endoplasmic reticulum (ER) is the main storage site of Zn, and Zn plays an important role in regulating ER homeostasis. Therefore, we designed and synthesized a ratiometric fluorescent Zn probe ER-Zn targeting ER stress. The probe displayed a specific Zn induced blue shift at the spectral maximum values of excitation (80 nm) and emission (30 nm). The ratio imaging capability of Zn under dual excitation mode can be applied not only to quantitative and reversible detection of exogenous Zn, but also the observation of the Zn level change under ER stress, elucidating the different behaviors of Zn release in ER stimulated by tunicamycin and thapsigargin. Additionally, the NIR imaging capability of ER-Zn provides an important basis for further research on animal models and is expected to realize the visualization and treatment of ER stress-related diseases through the regulation of ER stress by Zn. We envision that this probe can be applied to screen drugs for diseases related to ER stress regulation.