The fluorescence of a mercury probe based on osthol.

Guangyan Luo,Zhu Tao,Lin Zhang,Qianjun Zhang,Zhishu Zeng

doi:10.3762/bjoc.17.3

Abstract

The ability of osthol (OST) to recognize mercury ions in aqueous solution was studied using fluorescence, UV–vis spectrophotometry, mass spectrometry, and 1H NMR spectroscopy, and the recognition mechanism is discussed. The results showed that OST and Hg2+ can form a complex with a stoichiometric ratio of 1:1. The binding constant was 1.552 × 105 L∙mol−1, having a highly efficient and specific selectivity for Hg2+. The fluorescence intensity of OST showed a good linear correlation with the Hg2+ concentration (6.0 × 10−5 to 24.0 × 10−5 mol∙L−1, R2 = 0.9954), and the detection limit of the probe was 5.04 × 10−8 mol∙L−1, which can be used for the determination of Hg2+ traces.

Highlights

When adding different metal ions (Hg2+, Ca2+, Na+, Mg2+, Al3+, Cd2+, Cu2+, Pb2+, Ni2+, Co2+, Fe3+, Ag+, Cr3+, and other metal ions) in 10 times the equivalent concentration to the OST probe, only Hg2+ produced an obvious fluorescence enhancement, and the other metal ions had little effect on the fluorescence intensity of OST, which indicates that the probe had a high selectivity for Hg2+
It is found that Fe3+ had a certain fluorescence quenching effect on the system due to the paramagnetism [25], but the fluorescence quenching effect was not enough to affect the recognition of mercury ions by the probe, and the presence of other coexisting metal ions did not affect the fluorescence spectrum change of the OST–Hg2+ system
The linear relationship between the magnitude of the increase in the fluorescence intensity and the concentration of the mercury ions was in the range of 6.0 × 10−5 to 24.0 × 10−5 mol∙L−1 (Figure 4)

Summary

Introduction

The probe had a high selectivity and sensitivity for Hg2+ recognition and can be used for the quantitative detection and monitoring of mercury ions in the environment. When adding different metal ions (Hg2+, Ca2+, Na+, Mg2+, Al3+, Cd2+, Cu2+, Pb2+, Ni2+, Co2+, Fe3+, Ag+, Cr3+, and other metal ions) in 10 times the equivalent concentration to the OST probe, only Hg2+ produced an obvious fluorescence enhancement (the intensity increased sharply by about 27 times), and the other metal ions had little effect on the fluorescence intensity of OST, which indicates that the probe had a high selectivity for Hg2+.

Results

Conclusion