Thiophene-fused 1,10-phenanthroline toward a far-red emitting conjugated polymer and its polymer dots: synthesis, properties and subcellular imaging

We synthesized and characterized a new kind of far-red emitter based on a conjugated block copolymer obtained from fluorene, 4,7-di(thiophen-2-yl) benzo[c][1,2,5] thiadiazole and thiophene-fused 1,10-phenanthroline. Compact polymer dots (Pdots) that show intense fluorescence signals in the far-red and near-infrared regions were formed by nanoprecipitation. Their small particle size, high brightness, non-toxic feature, and ability to specifically target subcellular structures make them promising probes for biological imaging.