A new method for fabricating fluorescent nanofibers as sensing materials was developed via the electrospinning technique using fluorophore-doped polymers. Fluorescent nanofibers with diameters in the range 200-600 nm were produced with fluorophores dispersed uniformly in the matrix. Sensing nanofibers with secondary porous structures were further achieved by introducing a porogen or deacetylation treament as a new approach, exhibiting unique morphologies with intra-fiber pores and obviously improved quenching sensitivity. Methyl violet was used as a model to investigate the sensing performance of a nanofiber membrane composed of cellulose acetate doped with 9-chloromethylanthracene. This work provides a simple and applicable strategy for the fabrication of sensing materials for optical sensor devices.