Langmuir monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) formed at the air-water interface were used as simple models of biological membranes to study interactions with two selected perfluorinated compounds: perfluorooctanoic acid (PFOA) and perfluorooctanesulphonic acid (PFOS). The presence of those common pollutants in the subphase led to the formation of more fluidic monolayer possessing different surface and barrier properties. The observed increase in the area per molecule in the Langmuir monolayer spread at the air-water interface was attributed to the incorporation of perfluorinated compounds into the layer. Moreover, perfluorooctanesulphonic acid was found to interact with DPPC monolayers transferred onto the electrode surface. Exposure of DPPC modified electrode to PFOS solution led to changes in electrode capacitance and in the efficiency of electron transfer rate observed for selected electroactive probes added to the solution.