A bifunctional fluorescence probe for dual-channel detecting of mitochondrial viscosity and endogenous/exogenous peroxynitrite.

The irregular viscosity in the mitochondrial can induce mitochondrial dysfunction. The content of peroxynitrite (ONOO) is related to various physiological and pathological processes. However, many mitochondrial probes only realized the detection of viscosity or ONOO in single channel, thus it is necessary to explore single fluorescence probe for dual-detecting mitochondrial viscosity and ONOO. In this work, we designed and synthesized a novel fluorescence probe (PV) for dual-detecting viscosity and ONOO, which was composed by intergrating a ONOO- responsive arlyboronate with a twisting intramolecular charge transfer (TICT) mechanism and possessed the mitochondria-targeting ability due to its pyridinium cation. PV exhibited a significant increase in viscosity with red emission at 582 nm and high sensitivity to ONOO levels with yellow emission at 507 nm. PV was also applied to living systems (including living cells and zebrafish) for viscosity and ONOO detection using two different channels. Moreover, the ability of PV to track mitophagy may make ONOO a powerful tool for its role in mitophagy.