A high-resolution mitochondria-targeting ratiometric fluorescent probe for detection of the endogenous hypochlorous acid

•A novel mitochondria-targeting ratiometric fluorescent probe HPQ-Cy2 was developed for detection hypochlorous acid.•The probe HPQ-Cy2 possesses large Stokes shift (210 nm).•A rapid-response time was within 50 s for detection hypochlorous acid.•It was successfully applied for the detection of endogenous hypochlorous acid in mitochondria.

Hypochlorite anion, one of the biologically important reactive oxygen species, plays an essential role in diverse normal biochemical functions and abnormal pathological processes. Herein, an efficient high-resolution mitochondria-targeting ratiometric fluorescent probe for hypochlorous acid detection has been designed, synthesized and characterized. It is easily synthesized by the condensation reaction (CC) of a 2-(2-hydroxyphenyl) quinazolin-4(3H)-one fluorophore and a cyanine group (mitochondria-targeting), which made the whole molecular a large Stokes shift (210 nm) and the two well-resolved emission peaks separated by 140 nm. As a result, it is considered as a good candidate for high resolution hypochlorous acid imaging in live cells. The ratiometric fluorescent probe exhibited outstanding features of high sensitivity, high selectivity, rapid response time (within 50 s), and excellent mitochondria-targeting ability. Moreover, the probe can also be successfully applied to imaging endogenously hypochlorous acid in the mitochondria of living cells with low cytotoxicity, and high resolution.

Graphical abstractThe ratiometric fluorescent probe HPQ-Cy2 possesses a large Stokes shift (210 nm), and the two well-resolved emission peaks separated by 140 nm, so it is considered as a good candidate fluorescent probe for high resolution ClO− imaging in subcellular organelles of living cells.Figure optionsDownload full-size imageDownload as PowerPoint slide