Development of an Endoplasmic Reticulum-targeting Fluorescent Probe for the Imaging of Superoxide Anion in Living Cells.

Superoxide anion (O₂^•−) is an important reactive oxygen species (ROS), and plays critical roles in biological systems. ER stress has close relation with many metabolic diseases, and could lead to the abnormal production of ROS including O₂^•−. Herein, we present an ER-targeting probe (ER-Tf) for the detection of O₂^•− in living cells. The probe ER-Tf used triflate as the response site for O₂^•−, and employed p-methylbenzenesulfonamide as ER-targeting moiety. In response to O₂^•−, the triflate of the probe ER-Tf converted to hydroxyl group, providing strong blue emission under the excitation of ultraviolet light. The probe ER-Tf exhibited high sensitivity and selectivity to O₂^•−. Bioimaging experiments showed that the probe ER-Tf can be applied to detect O₂^•− at ER, and also demonstrated that rotenone could increase the generation of O₂^•− in living cells, while the O₂^•− level at ER showed no remarkable change during ferroptosis. [ABSTRACT FROM AUTHOR]