Real-time detection of attenuated blood polarity in mouse models of circulating tumor based on a fluorescent probe

Polarity, as a microenvironmental parameter, which is closely related to the diagnosis of many diseases, especially cancer. Except for the polarity changes of solid tumor regions, the changes of blood polarity have received little attention. However, the polarity changes of blood would be the feedback of circulating tumor. Herein, a robust fluorescent probe Nile-Tpa has been rationally designed for the detection of polarity. In addition to polarity detection in vivo and in vitro, the new probe Nile-Tpa also reveals the dynamic changes of blood polarity through normal mice and mouse models of circulating tumor. Best of all, attenuated blood polarity was successfully perceived in circulating tumor mice for the first time with only 5–10 μL of blood. This non-invasive method may provide practical significance for diagnosis of cancer metastasis.