A mitochondrion targetable dimethylphosphorothionate-based far-red and colorimetric fluorescent probe with large Stokes shift for monitoring peroxynitrite in living cells

Abstract

Peroxynitrite (ONOO⁻) is a biological oxidant that is related to numerous physiological and pathological processes. An overdose of ONOO⁻ is the cause of various serious diseases. Some evidence demonstrates that mitochondria are the major sites of ONOO⁻ production. Therefore, monitoring mitochondrial ONOO⁻ is important to understand the related pathological processes in living systems. Herein, a colorimetric and far-red fluorescent sensing probe (PCPA) for the determination of ONOO⁻ was constructed based on a dicyanoisophorone skeleton using dimethylphosphorothionate as the recognition group and pyridine salt as the mitochondrion-targeting unit. PCPA showed a far-red fluorescence response to ONOO⁻ accompanied by a distinct color change from colorless to yellow via the ONOO⁻ induced deprotection of dimethylphosphorothionate. In addition, PCPA exhibited a large Stokes shift (200 nm), high selectivity detection and high sensibility (LOD = 39 nM). Furthermore, PCPA was successfully employed for imaging ONOO⁻ and tracing ONOO⁻ in mitochondria. PCPA presents a new recognition group and has potential applications in the biology field.