A simple fluorophore/surfactant ensemble as single discriminative sensor platform: Identifying multiple metal ions in aqueous solution

Abstract A simple imidazolium-modified mono-pyrene derivative ( Py-IM ) is synthesized. SDS assemblies modulate its fluorescence emission from monomer emission in neat aqueous solution to monomer-excimer co-emission in pre-micelles and to monomer emission again in micellar solutions. The ensemble based on Py-IM and SDS assemblies exhibiting both monomer and excimer emission displays multiple-wavelength cross-reactive responses to cationic metal ions. This single sensor system could well discriminate 6 quenching metal ions (Fe 3+ , Cu 2+ , Pb 2+ , Ni 2+ , Co 2+ , and Mn 2+ ) through principal component analysis method. Control experiments with Py-IM in the absence of SDS assemblies and in SDS micellar solutions reveal that the modulation effect of surfactant assemblies plays an important role in the cross-reactive responses of the cationic probe, which provides a general way of fabricating discriminative single sensor systems.