Bifunctional Single-Molecular Fluorescent Probe: Visual Detection of Mitochondrial SO<sub>2</sub> and Membrane Potential
Wenming Ai, Yingcui Bu, Houshi Huang, Junjun Wang, Mengjuan Ren, Yu Deng, Yicai Zhu, Sen Wang, Zhipeng Yu, Hongping Zhou
Abstract
Mitochondrial membrane potential (MMP) and sulfur dioxide (SO 2 ) significantly affect the mitochondrial state. In this work, TC-2 and TC-8 were constructed through side-chain engineering, in which TC-2 bearing the poorer hydrophobicity could localize on mitochondria better. Interestingly, short-wave emission was captured due to the sensitive response of TC-2 to SO 2 (LOD = 13.8 nM). Meanwhile, the probe could bind with DNA, presenting enhanced long-wave emission. Encouragingly, TC-2 could migrate from mitochondria to the nucleus when MMP was decreased, accompanied by the increase of fluorescence lifetime (9-fold). Hence, TC-2 could be used for dual-channel monitoring of mitochondrial SO 2 and MMP, which showed a completely different pathway from the commercial MMP detectors JC-1/JC-10. The cellular experiments showed that MMP was gradually decreased due to reactive oxygen species-triggered oxidative stress, and the SO 2 level was up-regulated simultaneously. Overall, this work proposed a new method to investigate and diagnose the mitochondrial-related diseases.