Selective Sensing of Metal Ions and Nitro Explosives by Efficient Switching of Excimer-to-Monomer Emission of an Amphiphilic Pyrene Derivative

An
amphiphilic pyrene derivative exhibiting unusually stable excimer
emission due to strong aggregation is presented. The aggregated system
served as an intelligent sensor for metal ions and nitro explosives
in aqueous media. The excimer displayed excellent selectivity toward
Cu2+ among the tested cations. The observation
was interpreted on the basis of chelation of metal ions involving
the hydroxyl and amino groups of two molecules, leading to the ligand-to-metal
charge-transfer (CT) process. The excimer was further applied for
the cell imaging of Cu2+ ions. Also, while treating the
excimer with various nitro explosives, it displayed efficient 2,4,6-trinitrophenol
sensing, corroborating mainly the CT process from pyrene to the analyte
due to intercalation of the analyte within pyrene.