We realized a printed immunosensor based on a competitive enzyme-linked immunosorbent assay (ELISA) to allow histamine detection. We investigated the effect of modifying the immunosensor electrodes with spray-deposited poly(3,4-ethyldioxythiophene)poly(styrenesulfunate) (PEDOT:PSS) and single walled carbon nanotube (SWCNT) films. Cyclic voltammetry (CV) was used to characterize the sensor performance and to prove an enhancement of the electrode active surface area up to 29.1%, due to the use of the additional PEDOT:PSS/SWCNT film. The calibration curve of the so-realized immunosensor (obtained by chronoamperometry measurements) shows a linear detection range of histamine from 0.05 to 50 ng/ml, with 95.03% coefficient of determination.