An excitation ratiometric Zn2+ sensor with mitochondria-targetability for monitoring of mitochondrial Zn2+ release upon different stimulations

A mitochondria-targeted fluorescent sensor (Mito-ST), constructed by integrating a sulfamoylbenzoxadiazole fluorophore with a phosphonium group, displays the specific Zn2+ -induced hypsochromic shifts of both excitation (69 nm) and emission (35 nm) maxima. Its ratiometric Zn2+ imaging ability via dual excitation mode has been applied in MCF-7 cells to clarify the different behaviours of mitochondrial Zn2+ release stimulated by H2O2 and SNOC.