Rapid self-calibrating fluorescent detection of copper (II) ions in wine with high accuracy.

Excessive copper in wine can cause formation of oxidation reactions and affect the quality of wine. Herein, a rapid self-calibrating fluorescence sensing system for the detection of copper (II) ions in wine was developed. The sensing system has a dual-emission peak of 480 nm and 550 nm at the excitation wavelength of 390 nm. Only the yellow fluorescence can be selectively quenched by copper (II) ions. In contrast, the blue fluorescence stays almost constant, resulting in the apparent change of fluorescence image from yellow to blue. The reaction can be completed within 8 s. The sensing system showed a good linear relationship with copper (II) ions concentration in 0-4 μmol/L, with a detection limit of 46.5 nmol/L. Based on this sensing system, a fluorescent dual-tube detection bottle was designed to detect copper (II) ions more conveniently and was successfully applied to detect copper (II) ions in wine.