Chromophore‐Modified Highly Selective Ratiometric Upconversion Nanoprobes for Detection of ONOO−‐Related Hepatotoxicity In Vivo

Acute hepatitis is a major problem affecting public health and has attracted more and more attention. Generally, as the standard means, blood tests are taken for evaluating hepatitis. However, such tests fail to accurately reflect the level of hepatitis in vivo. Herein, two highly selective ratiometric fluorescent probes are designed to track peroxynitrite (ONOO−) as the hepatitis indicator, and further evaluate acute liver injury in vivo through dye‐grafted upconversion nanoparticles (UCNPs). Specifically, upconversion luminescence of nanoprobes at 540 or 660 nm can be quenched by the designed and synthesized chromophore E‐CC or H‐CC, that can be destroyed by ONOO− via energy transfer (ET) process, while the upconversion luminescence intensity at 810 nm remains the same. Thus, the developed nanoprobes can be used for ratiometric detection (I540/I660 or I660/I810) of ONOO−. Moreover, the developed near infrared ratiometric nanoprobes can highly selectively detect ONOO−, which can eliminate the interference of HOCl and SO32−. Finally, it is demonstrated that this highly selective ratiometric nanosystem can achieve effective detection of ONOO− in living cells and CCl4‐induced acute liver injury models. It provides some reference value for clinical detection of hepatotoxicity. Highly selective near‐infrared ratiometric fluorescent nanoprobes are designed to track the acute hepatotoxicity‐related reactive nitrogen species (RNS) peroxynitrite ONOO−. The nanosystem can estimate the content of ONOO− based on relative fluorescence intensity, and to further realize the assessment of acute liver injury in vivo.