A ratiometric ESIPT fluorescent probe for detection of anticancer-associated H2O2 level in vitro and in vivo

ROS is a significant factor in the cancer treatment mechanism. The monitoring anticancer-associated H2O2 level plays a vital role in the anticancer mechanistic exploration in pathology and physiology. Herein we synthesized a ratiometric fluorescent probe (HBQ-L) to detect and image H2O2 based on excited-state intramolecular proton transfer. HBQ-L had a high sensitivity (231-fold) with a low detection limit (28.5 nM) for monitoring H2O2 in solution. HBQ-L showed good mitochondrial-targeting and successfully detected both exo-/endogenous H2O2 in A549 cells. Furthermore, HBQ-L was used to ratiometric monitor H2O2 level in anticancer reagent DOX-treated cells or zebrafish. Importantly, it was employed to access the monitoring H2O2 in the A549 tumor-bearing mice.