Different plasma processes were investigated to obtain coatings characterized by N- and O-functional groups at their surface. From the literature, big efforts are evident devoted to designing new surfaces with chemical composition and chemical-physical properties tightly controlled. This paper demonstrates how it is possible to obtain coatings with acid and basic properties at different extent, by simply adjusting the acrylic acid/allylamine chemical composition of the gas feed in a plasma deposition process. The deposited films exhibit tuneable acid-base properties, very attractive to manufacture sensors, and biomaterials, and for applications in tissue engineering field.