Iron plays an essential role in biological system. An approach for in vivo imaging of this metal ion is needed to investigate its complex contributions to physiological and pathological processes. Herein, we present a bioluminescent probe FP-1 as a powerful tool for targeting Fe2+ detection in vitro and in vivo. The turn-on sensing scheme is based on the caged strategy of luciferin-luciferase system. FP-1 not only can detect accumulations of exogenous Fe2+ in living animal, but also has the capability of monitoring labile endogenous Fe2+ levels in animal model of sepsis. Implementation of this technique provides a valuable opportunity for understanding underlying mechanisms of Fe2+ in biological processes and disease states.
