A turn-on mitochondria-targeted fluorescent probe for detecting and imaging hydrogen peroxide in vitro and in vivo

In this work, we designed and synthesized a turn-on fluorescent probe for detecting H2O2. The results demonstrated that probe JQ-1 exhibited a high selectivity for H2O2. In addition, probe JQ-1 exhibited excellent sensitivity (detection limit: 87 nM) and a fast response time (∼10 min). Organelle co-localization experiment showed that JQ-1 mainly targeted mitochondria, which provided possibility to detect change of H2O2 level in mitochondria. JQ-1 can be used to image exogenous and endogenous H2O2 in vitro and vivo. Meanwhile, we used JQ-1 as fluorescence dye to investigate the change of H2O2 level during immunogenic cell death for the first time by confocal laser scanning microscopy and flow cytometry, and the results showed that H2O2 level had negligible change in process. Therefore, the results suggested that this probe is a reliable chemical tool for monitoring both endogenous and exogenous H2O2.