基于胆红素荧光增强效应的锌离子探针特性研究

Based on the fluorescence enhancement effect of Zn²⁺ on bilirubin (BR), this work proposes a new method for the detection of Zn²⁺ concentration, and a systematically investigation of BR as a Zn²⁺ probe by using ultraviolet-visible light absorption and steady-state fluorescence spectroscopy has been conducted. Compared with the general single-wavelength fluorescence intensity method, this new detection method eliminates the impacts of the non-target effects of factors such as concentration variation of BR and the excitation light intensity, etc., and achieves a more accurate measurement capability in Zn²⁺ detection. Especially, for the first time we adopt the BR fluorescence intensities ratio at the emission wavelengths 663 and 600 nm, and investigate the dependence between this ratio and the Zn²⁺ concentration in the range from 0 to 90 μmol•L^-1. The recognition behavior of BR probe to Zn²⁺ indicates that the BR fluorescence intensity ratio I_{663 nm}/I_{600 nm} increases linearly with the Zn²⁺ concentration in the range of 0~20 μmol•L^-1. In particular, in the range 0~10 μmol•L^-1 of Zn²⁺ concentration, the linear correlation coefficient r is 0.999 87, which demonstrates the linear dependence, and the detection limit is 0.1 μmol•L^-1. In the Zn²⁺ concentration range from 20 to 90 μmol•L^-1, the probe BR fluorescence intensity ratio is saturated. Accordingly, there is a positive prospect of BR fluorescence in the real-time human body Zn²⁺ detection.