A fast-response two-photon fluorescent probe for imaging endogenous H₂O₂ in living cells and tissues

As a second messenger, hydrogen peroxide plays significant roles in numerous physiological and pathological processes and is related to various diseases including inflammatory disease, diabetes, neurodegenerative disorders, cardiovascular disease and Alzheimer's disease. Two-photon (TP) fluorescent probes reported for the detection of endogenous H₂O₂ are rare and most have drawbacks such as slow response and low sensitivity. In this report, we demonstrate a simple H₂O₂-specific TP fluorescent probe (TX-HP) containing a two-photon dye 6-hydroxy-2,3,4,4a-tetrahydro-1H-xanthen-1-one (TX) on the modulation of the ICT process. The probe exhibits a rapid fluorescent response to H₂O₂ in 9min with both high sensitivity and selectivity. The probe can detect exogenous H₂O₂ in living cells. Furthermore, the probe is successfully utilized for imaging H₂O₂ in liver tissues.