The affinity and repartition of silver nanoparticles in different plasma polymer matrices are studied according to the polymer functional groups. The polymer layers are synthesized by plasma polymerization of allyl alcohol (AAl), aniline (ANI), or heptadecafluoro-1-decene (HDFD). The matrix is then impregnated in a metallic salt solution and a reducing one. When plasma-polymerized (pp) ANI is used as matrix, a higher amount of silver nanoparticles (AgNPs) is introduced compared to the other two polymer matrices. Otherwise, with pp-AAl, smaller AgNPs with narrower size distribution are inserted. Finally, different plasma polymer/AgNPs interaction mechanisms are proposed according to the polymer functional groups. Moreover, the sensing behavior of pp-ANI, well known as sensitive layer toward ammonia, is markedly enhanced by the presence of AgNPs.