Highly-aligned luminescent electrospun nanofibers were successfully prepared from two binary blends of PFO/PMMA and PF(+)/PMMA. The PFO/PMMA aligned electrospun fibers showed a core/shell structure but the PF+/PMMA fibers exhibited periodic aggregate domains in the fibers. The aligned fibers had polarized steady-state luminescence with a polarized ratio as high as 4, much higher than the non-woven electrospun fibers or spin-coated film. Besides, the PF(+)/PMMA aligned electrospun fibers showed an enhanced sensitivity to plasmid DNA. Such C aligned electrospun fibers could have potential 0 applications in optoelectronic or sensory devices.