A new simple fluorescent probe for imaging endogenous hydrogen peroxide in RAW 264.7 cells

One of the most significant species that are present in large quantities in biological cells is reactive oxygen species (ROS). They are essential for cell motility, cell differentiation, and cellular immunity. In this paper, we introduce that (E)-1-methyl-4-(4-(propionyloxy)styryl)pyridin-1-ium (MPSPI) is an "on" type fluorescent probe regulated by the ICT mechanism. After the addition of hydrogen peroxide, the fluorophore (E)-4-(4-hydroxystyryl)-1-methylpyridin-1-ium (HMI-OH) is released. The simple probe MPSPI not only exhibited good selectivity and low cytotoxicity, but also demonstrated a detection limit as low as 35 nM and reaction times as quick as 20 s. Moreover, it has been successfully applied to the imaging of hydrogen peroxide in RAW 264.7 cells.