Two ratiometric fluorescent probes for hypochlorous acid detection and imaging in living cells

Hypochlorous acid plays a very important role in living cells, because it can resist microorganism attack and has a lethal effect on pathogens. The unnormal generation of ClO- can cause tissue damage and corresponding diseases. Detection of ClO- is very necessary in biological systems. In this article, we respectively hybridized the two different water-soluble coumarin (7-hydroxycoumarin and 7-diethylaminocoumarin) fluorophores with a longer-wavelength emissive rhodamine fluorophore to construct an intergrant, and then isothiocyanate was modified with the intergrant to recognized ClO-. The two ratiometric fluorescent probes RHClO-1 and RHClO-2 were developed for ClO- detecting with high selectivity and sensitivity. Especially, the probe RHClO-2 has lower detection limit (42 nM) for ClO- in 5 s. What's more, the probe RHClO-2 was successfully used in monitoring endogenous ClO- in living cells.