4-Nitroaniline was electropolymerized in a weakly alkaline medium, and the resulting poly(4-nitroaniline) (P4-NA)) was used to fabricate - by electrospinning - a nanofiber consisting of P4-NA and poly(vinyl alcohol) (PVA). The PVA fraction was then dissolved in hot water and this causes the porosity of electrospun nanofiber to be largely enhanced. The resulting nanofiber was utilized as a sorbent for solid phase microextraction of the model organophosphorus pesticides diazinon and chloropyrifos from aqueous media. The extracted analytes were then analyzed by corona discharge ion mobility spectrometry (CD-IMS). Under the optimized conditions, the limits of detection (at S/N = 3; for n = 10) are 0.4 and 0.6 ng mL(-1) for diazinon and chloropyrifos, respectively. The relative standard deviations at the levels of 25, 50 and 100 ng mL(-1) (for n = 3) ranged from 4.0-12.3% (both intra-day and inter-day). Eventually, the method was used to analyze different water samples, including spiked drinking water, sea water, lagoon water, and groundwater sample in the proximity of rice fields, and in two juice samples. Recoveries ranged between 82 and 102%.