A highly effective "turn-on" camphor-based fluorescent probe for rapid and sensitive detection and its biological imaging of Fe.

In this work, a novel fluorescent probe CBO was synthesized for detecting Fe using the natural monoterpenketone camphor as the starting material. The probe CBO displayed turn-on fluorescence to Fe accompanied by the solution change from colorless to green. As expected, there was an excellent linear relationship between the fluorescence intensity of probe CBO and the concentration of Fe (0-20 μM), and the detection limit was as low as 1.56×10 M. In particular, CBO could selectively sense Fe more than other analytes (Fe included) through the N-oxide strategy, and quickly responded to Fe (60 s) over a wide pH (4-14) range. Additionally, based on the rapid fluorescence response of CBO to Fe, a simple test strip-based detector was designed for boosting practical applicability. The probe CBO had been successfully applied to the fluorescence imaging of Fe in onion cells and living zebrafish. The probe CBO was a powerful tool of detecting Fe level in organisms, which was of significance to understand the role of Fe in Fe-related physical processes and diseases.