Illuminating peroxynitrite in acute liver injury with a responsive optical probe.

Peroxynitrite (ONOO-) constitutes a key biomolecule tightly linked to oxidative stress and plays a profound role in the pathological mechanisms underlying acute liver damage and tumorigenesis. Because ONOO- levels exhibit strong associations with disease status, precise and dynamic detection of this species is essential for early-stage clinical diagnosis. Consequently, capturing real-time variations of ONOO- in pathological contexts carries considerable significance for both timely disease identification and therapeutic evaluation. Fluorescence imaging provides a highly sensitive, minimally invasive, convenient, and selective platform for in situ detection and spatiotemporal mapping of ONOO- within complex biological environments. In the present work, we designed a fluorescent probe, termed YZZ, built upon a hemicyanine framework, which enables specific recognition and visualization of ONOO- both in vitro and in vivo. The probe demonstrates outstanding selectivity and superior sensitivity for ONOO-. Cellular imaging experiments verified that YZZ is capable of tracking both endogenous and exogenous ONOO- pools in living systems. In addition, this study validated the probe's applicability for in vivo tissue imaging, allowing clear visualization of ONOO- in stimulated, injured liver tissues. To the best of our knowledge, this is one of the few studies that systematically examines ONOO- fluctuations in hepatic injury models.