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.