Rhodamine-Based Fluorescent Probe for Highly Selective Determination of Hg2+

The determination of mercuric ions (Hg2+) in environmental and biological samples has attracted the attention of researchers lately. In the present work, a novel turn-on Hg2+ fluorescent probe utilizing a rhodamine derivative had been constructed and prepared. The probe could highly sensitively and selectively sense Hg2+. In the presence of excessive Hg2+ , the probe displayed about 52-fold fluorescence enhancement in 50% H2O/CH3CH2OH (pH, 7.24). In the meantime, the colorless solution of the probe turned pink upon adding Hg2+. Upon adding mercuric ions, the probe interacted with Hg2+ and formed a 1:1 coordination complex, which had been the basis for recognizing Hg2+. The probe displayed reversible dual colorimetric and fluorescence sensing of Hg2+ because rhodamine's spirolactam ring opened upon adding Hg2+. The analytical performances of the probe for sensing Hg2+ were also studied. When the Hg2+ concentration was altered in the range of 8.0 x 10(-8) to 1.0 x 10(-5) mol L-1 , the fluorescence intensity showed an excellent linear correlation with Hg2+ concentration. A detection limit of 3.0 x 10(-8) mol L-1 had been achieved. Moreover, Hg2+ in the water environment and A549 cells could be successfully sensed by the proposed probe.

Automated summary

The determination of mercuric ions (Hg2+) in environmental and biological samples has attracted researchers' attention lately. In this study, a novel turn-on Hg2+ fluorescent probe utilizing a rhodamine derivative has been constructed, which can sensitively and selectively sense Hg2+. The probe shows reversible dual colorimetric and fluorescence sensing of Hg2+ through forming a 1:1 coordination complex with Hg2+.