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

Since HOCl plays an indispensable role in a variety of physiological and pathological processes, monitoring the level of hypochlorous acid (HOCl) in living cells is critical. Based on this, it is necessary to develop a convenient and simple technique to detect HOCl in living cells. In this contribution, a simple 2-hydroxy-6-morpholino-1H-benzo[de]isoquinoline-1,3(2 H)-dione (NDS) was developed as fluorescent probe for monitoring HOCl in live cells. Probe NDS exhibited preeminent specificity towards HOCl over other various bioactive substances. In addition, the probe could respond to HOCl in solutions within 16 s and the limit of detection was as low as 105.24 nM. NDS has good lysosomal targeting and has been successfully applied to the expression of exogenous and endogenous lysosomal HOCl in HeLa cells. This study provides a promising tool for studying physiological or pathological related processes.