A near infrared fluorescent probe for rapid sensing of peroxynitrite in living cells and breast cancer mice.

Peroxynitrite (ONOO) plays an essential role in numerous physiological and pathological processes owing to its strong oxidation and nitrification. Many studies have shown that ONOO abnormalities are associated with inflammatory diseases, even cancer, such as arthritis, hepatitis, pneumonia, and breast cancer. Thus, developing a trustworthy technology to monitor ONOO levels is critical in inflammatory or cancer illnesses. Herein, an ultrafast near-infrared (NIR) fluorescent probe (Cy-OH-ONOO) is proposed to detect ONOO within 30 s. The probe's borate moiety is oxidized and separated from Cy-OH-ONOO, releasing a NIR fluorescence signal after interacting with ONOO under physiological circumstances. In addition, the probe displays good selectivity and sensitivity towards ONOO compared to other related biological species. Moreover, it is applied to the image and detects the level fluctuation of ONOO in living cells and breast cancer mice based on excellent features with high biocompatibility and low toxicity of the developed probe. Therefore, Cy-OH-ONOO could serve as a powerful imaging tool to understand the correlation of ONOO with inflammatory or breast cancer pathophysiological processes and to assess ONOO levels in cellular oxidative stress.