||Due to the highly sensitive quenching response of p-type poly(p-phenyleneethylene)s (PPEs) towards analytes such as 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (DNT), thin films of PPEs have been applied to explosive sensing. The superb selectivity has been known to link to the binding strength between fluorescent polymers and analytes. The strong binding strength, however, prevents nitroaromatic systems such as DNT and TNT from diffusing deeper into polymer films, leading to diminished response from thick films. Herein, we report a preparation of nanoporous thin films of p-type PPE through the non-solvent vapor induced phase separation (NVIPS). Well-defined films with regular nanopores of ~50 nm were obtained through the simple phase separation process. We expect that the introduction of nanoporosity into the polymer film would lead to enhanced diffusion rate of analytes into the film, resulting in higher sensory response when compared with normal spun-cast thin films.