Synthesis and bioimaging of a BODIPY-based fluorescence quenching probe for Fe.

Iron is the main substance for maintaining life. Real-time determination of ferric ion (Fe) in living cells is of great significance for understanding the relationship of Fe concentration changes with various physiological and pathological processes. Fluorescent probes are suitable for the detection of trace metal ions in cells due to their low toxicity and high sensitivity. In this work, a boron-dipyrromethene-based fluorescent probe (BODIPY-CL) for selective detection of Fe was synthesized. The fluorescence emission of BODIPY-CL was determined at 516 nm. In a pH range of 1 to 10, the probe BODIPY-CL exhibits a quenching response to Fe. Meanwhile, BODIPY-CL showed a highly selective response to Fe compared with 16 kinds of metal ions. The stoichiometry ratio of BODIPY-CL bound to Fe was nearly 2 : 1. The fluorescence quenching response obtained by the sensor was linear with the Fe concentration in the range of 0-400 μM, and the detection limit was 2.9 μM. BODIPY-CL was successfully applied to image Fe in cells. This study provides a promising fluorescent imaging probe for further research on the physiological and pathological effects of Fe.