A Colorimetric and Fluorescent Probe Based on Rhodamine B for Detection of Fe3+ and Cu2+ Ions

Development of optical probe for the detections of Fe3+ and Cu2+ is one of the most active and interesting research directions in analytical chemistry because of their vital roles in the environment protection and human health. Herein, a turn on optical rhodamine B-based probe (probe 1) with the significant changes in color and fluorescence has been prepared. The color of this probe solution changed from colorless to amaranth in the presence of Fe3+ and to pink in the presence of Cu2+, which is promising for the qualitative recognition of Fe3+ and Cu2+. More importantly, probe 1 could be used for the quantitative analysis of Fe3+ and Cu2+ by fluorescence enhancement. The detection limits for Fe3+ and Cu2+ reached 8.1 × 10−8 M and 4.8 × 10−7 M, respectively. Furthermore, it was found that this probe can also be used for fluorescence imaging of Fe3+ and Cu2+ in living cells.