Tracking mitochondrial movement in neurons is an attractive research field as dysregulation of mitochondrial motion is associated with multiple neurological diseases. To attain the precise trajectory of a single mitochondrion and achieve long-term imaging of mitochondria in neurons, specific and photostable fluorescent probes with a long emission lifetime are required. Existing mitochondrial targeting fluorescent dyes suffer from poor photostability, high toxicity, “always-on” behavior, and aggregation-caused quenching effect, which limit their use in studying mitochondria in neurons. To overcome these challenges, we designed and synthesized an aggregation-induced emission (AIE)-active luminogen, TPAP-C5-yne, which consists of an activated alkyne terminus for bioconjugation with amines, and a cationic pyridinium moiety to selectively target mitochondria. For the first time using TPAP-C5-yne, we successfully tracked and analyzed the motion of a single mitochondrion in live primary hippocampal neurons accurately using real-time fluorescence images acquired by a sensitive EMCCD camera. In addition, long-term imaging of mitochondria in live neurons for a week is achieved by TPAP-C5-yne, which was not feasible with a commercially available mitochondrial targeting probe before.
Precise and Long-Term Tracking of Mitochondria in Neurons using a Bioconjugatable and Photostable AIE Luminogen