<p>Peroxynitrite (ONOO⁻), as a key reactive nitrogen species in organisms, is involved in various physiological and pathological processes, and its abnormal levels are closely related to various diseases. Food safety, as a major public health issue of global concern, is often associated with abnormal viscosity in the food system. Therefore, it is crucial to develop detection tools that can monitor these two key indicators. This study designed and synthesized a novel dual responsive fluorescent probe JY-1 based on a triphenylamine scaffold. Beyond its rapid response, high sensitivity (LOD = 57.7 nM), excellent selectivity, and strong anti-interference ability, real-time bioimaging of change of viscosity and endogenous ONOO⁻ have been successfully achieved with this probe in HeLa cells and zebrafish models, and the detection of ONOO⁻ has been successfully applied to life mice. Of particular importance, JY-1 has shown great potential in food safety applications: it can effectively identify viscosity changes caused by thickeners and track viscosity dynamics in real-time during beverage spoilage, demonstrating broad prospects of JY-1 in biological applications and food monitoring.</p> Graphical abstract <p></p>