Two birds with one stone: A highly sensitive near-infrared BODIPY-based fluorescent probe for the simultaneous detection of Fe2+ and H+ in vivo.

Abstract Ferrous ion (Fe2+) plays an essential role in many physiological and pathological processes, and its cellular metabolism is closely related to acidic pH. However, the lack of multifunctional Fe2+ probes has hindered the further study of Fe2+ in vivo. Herein, we report a dual-responsive near-infrared (NIR) fluorescent probe BODIPY-Fe for the simultaneous of Fe2+ and H+ in vivo by harnessing the N-oxide strategy and photoinduced electron transfer (PeT) mechanism. BODIPY-Fe exhibited NIR fluorescence at 671 nm, rapid response to Fe2+ within 90 s, and high sensitivity of low LOD of 292 nM towards Fe2+. Moreover, BODIPY-Fe could sensitively and selectively detect Fe2+ and H+ in the lysosomes of living cells simultaneously. Notably, BODIPY-Fe was able to noninvasively visualize Fe2+ and H+ in vivo, showing “ON-OFF-ON” NIR fluorescence signal changes. This work demonstrates that BODIPY-Fe has great potential to promote the simultaneous imaging of Fe2+ and H+ in biological systems.