A lysosome-targeted ratiometric fluorescent probe for detection of hypochlorous acid in living cells

Abstract A ratiometric fluorescent probe (DICX) based on Forster resonance energy transfer (FRET) system for hypochlorous acid (HOCl) was developed, in which coumarin moiety was connected to rhodamine by monothio-bishydrazide linker. DICX could fast respond to HOCl under acidic condition and showed high selectivity and sensitivity toward HOCl over other reactive oxygen species, reactive nitrogen species, and ions. The FRET energy transfer efficiency is very high (93.75%). Moreover, DICX could target lysosome and could be suitable for sensing exogenous and endogenous HOCl in living cells.