Assessment of environmental and biological stress using mitochondria-targeted red-emitting and near-infrared fluorescent probes for biothiol analysis: a review

Levels of biological thiols, or “biothiols,” in mitochondria can be used to assess environmental and biological oxidative stress, which can cause health issues such as malignant tumors and neurological diseases. Here, we review fluorescent probes for detecting biothiols, targeting mitochondria, and emitting red and near-infrared light, with focus on nitrogen cation and oxonium ion units as mitochondrial biomarkers. Red-emitting and near-infrared fluorescent probes for detecting biothiols are classified according to the way they target mitochondria. We present the structure, fluorescence behavior, and biological imaging of the probes.