A new selective colorimetric and fluorescent sensor for Hg2+ and Cu2+ based on a thiourea featuring a pyrene unit

A new artificial receptor 1 was developed, and its chromogenic and fluorogenic behaviors toward various metal ions were investigated. Receptor 1 shows exclusively responses toward Hg2+ and Cu2+ ions. It selectively senses Hg2+ and Cu2+ ions through two different color changes in aqueous solution (DMSO/H2O = 4/1) and also distinguishes them from other metal ions. In addition, receptor 1 also exhibits pronounced enhancements of the fluorescence, which can visually be discernible by an orchid fluorescence in the presence of Hg2+ ions and a strong blue fluorescence in the presence of Cu2+ ions.