A novel fluorescent probe (dtpa-bis(cytosine)) for detection of Eu(III) in rare earth metal ions

Abstract

In this paper, a novel fluorescent probe, dtpa-bis(cytosine), was designed and synthesized for detecting europium (Eu³⁺) ion. Upon addition of Eu³⁺ ions into the dtpa-bis(cytosine) solution, the fluorescence intensity can strongly be enhanced. Conversely, adding other rare earth metal ions, such as Y³⁺, Ce³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Gd³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺, Yb³⁺ and Lu³⁺, into dtpa-bis(cytosine) solution, the fluorescence intensity is decreased slightly. Some parameters affecting the fluorescence intensity of dtpa-bis(cytosine) solution in the presence of Eu³⁺ ions were investigated, including solution pH value, Eu³⁺ ion concentration and interfering substances. The detection mechanism of Eu³⁺ ion using dtpa-bis(cytosine) as fluorescent probe was proposed. Under optimum conditions, the fluorescence emission intensities of Eu^III-dtpa-bis(cytosine) at 375nm in the concentration range of 0.50×10^-5mol∙L^-1-5.00×10^-5mol∙L^-1 of Eu³⁺ ion display a better linear relationship. The limit of detection (LOD) was determined as 8.65×10^-7mol∙L^-1 and the corresponding correlation coefficient (R²) of the linear equation is 0.9807. It is wished that the proposed method could be applied for sensitively and selectively detecting Eu³⁺ ion.

Keywords: Cytosine; Detection of europium (Eu(3+)) ion; Diethylenetriaminepentaacetic acid (DTPA); Fluorescent probe; Rare earth metal ions.