FerroOrange is a fluorescent probe specifically designed for detecting ferrous ions (Fe²⁺) within live cells. Upon irreversible binding to Fe²⁺, FerroOrange undergoes a significant fluorescence enhancement, characterized by excitation at 543 nm and emission at 580 nm. Fluorescent imaging instruments, including fluorescence microscopy, flow cytometry, and plate readers, can all be employed for its detection. Due to iron's critical roles in biological systems, FerroOrange serves as a useful tool in investigating intracellular Fe²⁺ dynamics and associated physiological processes.