Polymer-based fluorescent sensor incorporating 2,2′-bipyridyl and benzo[2,1,3]thiadiazole moieties for Cu2+ detection

The polymer was synthesized by the polymerization of 4,4′-((4-iodophenoxy)methyl)-2,2′-bipyridine (M-1) with 4,7-diethynylbenzo[2,1,3]-thiadiazole (M-2) via Pd-catalyzed Sonogashira reaction. The fluorescence responses of the polymer towards various transition metal ions were investigated by fluorescence spectra and UV–Vis spectra. The polymer shows green fluorescence under ultraviolet lamp, which can be quenched by Cu2+ completely due to the heavy metal effect. The results suggested that the polymer can be used as a Cu2+-selective sensor via a naked eyes detecting mode.