Study on Characteristics of Zinc Ion Probe Based on Fluorescence Enhancement of Bilirubin

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 mu mol . 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 Z(2+) concentration in the range of 0 similar to 20 mu mol . L-1. In particular, in the range 0 similar to 10 mu mol . 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 mu mol . L-1. In the Zn2+ concentration range from 20 to 90 mu mol . 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.