A Multidimensional Undergraduate Experiment for Easy Solution and Surface Sensing of Mercury(II) and Copper(II) Metal Cations

The recently reported bis(1-pyrenyl)azine, easily prepared in a one-step reaction from 1-pyrenecarboxaldehyde and hydrazine hydrate, is used as a receptor for the visual detection of Hg 2+ and Cu 2+ ions in solution in an undergraduate laboratory experiment. The receptor was also supported on both filter paper and a hydrophobic PTFE (polytetrafluoroethylene) membrane, and the resulting probe-coated sheets were successfully used for selective sensing of the same metal ions using optical and fluorescent spectroscopies. This project provides an opportunity to organic chemistry students to learn about the challenging problem of selectively detecting toxic metal ions, such as Cu 2+ and Hg 2+, in solution.