A mitochondrial-targetable dual functional near-infrared fluorescent probe to monitor pH and H(2)O(2) in living cells and mice

A lower pH level and high hydrogen peroxide (H(2)O(2)) concentration in mitochondria is closely associated with a variety of diseases including cancer and inflammation. Thus, determination of changes in the level of acidic pH and H(2)O(2) is of great importance and could provide new insights into the key functions under both physiological and pathological conditions. Herein, we present a novel mitochondria-targetable probe NIR-pH-H(2)O(2), as the first near infrared (NIR) fluorescent small molecule, to monitor changes of endogenous pH (pk(a) = 6.17) and H(2)O(2) with high sensitivity, good compatibility and low cytotoxicity. Futhermore, it was successfully employed to monitor pH and H(2)O(2) in a mouse acute inflammation model. These results demonstrate that NIR-pH-H(2)O(2) is a novel bifunctional mitochondrial-targeted NIR probe to sense acidic pH and H(2)O(2)in vitro and in vivo, indicating its huge potential for the diagnosis of pH and H(2)O(2)-related diseases.