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

In this work, a novel fluorescent probe CBO was synthesized for detecting Fe²⁺ using the natural monoterpenketone camphor as the starting material. The probe CBO displayed turn-on fluorescence to Fe²⁺ 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 Fe²⁺ (0-20 μM), and the detection limit was as low as 1.56×10^-8 M. In particular, CBO could selectively sense Fe²⁺ more than other analytes (Fe³⁺ included) through the N-oxide strategy, and quickly responded to Fe²⁺ (60 s) over a wide pH (4-14) range. Additionally, based on the rapid fluorescence response of CBO to Fe²⁺, a simple test strip-based detector was designed for boosting practical applicability. The probe CBO had been successfully applied to the fluorescence imaging of Fe²⁺ in onion cells and living zebrafish. The probe CBO was a powerful tool of detecting Fe²⁺ level in organisms, which was of significance to understand the role of Fe²⁺ in Fe²⁺-related physical processes and diseases.