Development of an enhanced turn-on fluorescent HOCl probe with a large Stokes shift and its use for imaging HOCl in cells and zebrafish.

Hypochlorous acid (HOCl) plays a crucial role in the immune defence against invasive bacteria and other biological processes in living organisms. A turn-on fluorescent probe ( PZ-HA ) for sensitive detection of HOCl was developed. After the addition of HOCl, an approximately 80-fold enhancement in fluorescence intensity at 605 nm was observed. PZ-HA has a large Stokes shifts that can effectively avoid the self-absorption of the fluorescence. In addition, PZ-HA has excellent properties, including fast responsive, good selectivity and low cytotoxicity and well membrane-permeability. The potential of the probe as biosensor for HOCl was demonstrated by imaging of exogenous and endogenous HOCl in living cells. Further, the probe was applied to the fluorescence imaging of HOCl in zebrafish. Therefore the probe is expected to be useful for the accurate detection of HOCl in complex biosystems. [ABSTRACT FROM AUTHOR]