A novel flavonoid-based bioprobe for intracellular recognition of Cu2+ and its complex with Cu2+ for secondary sensing of pyrophosphate

Copper is a trace metal nutrient essential for most forms of life. The dysregulation of copper homeostasis is associated with various diseases, such as Menkes disease, Alzheimer's disease, Wilson disease, gastrointestinal disorders, and kidney damage. Therefore, detection of copper ions in biological system is of great significance for fundamental study in biology and medicine field. To address this critical need, we herein developed a novel flavonoid-based bioprobe 6-(bis(pyridin-2-ylmethypamino)-2-(4(dimethylamino)pheny1)-3-methoxy-4H-chromen-4-one (DPA-FL) for copper detection. The DPA-FL showed highly fluorescent response towards copper ions with a high tolerance of other competitive metal ions. The fluorescence intensity at 510 nm are linearly proportional to the amount of Cu2+ from 0 to 10 mu A with a detection limit lower than 100 nM (S/N rule). The intracellular recognition of copper ions was successfully achieved in HUVECs. Furthermore, the DPA-FL-Cu2+ complex could also be used for secondary sensing of pyrophosphate in living cells, thus providing a powerful imaging tool for tracking of copper ions and pyrophosphate in biological system. (C) 2016 Elsevier B.V. All rights reserved.