The article describes hybrid polymer nanoassemblies consisting of polymer nanosheets and metal nanoparticle arrays. Ultrathin polymer Langmuir-Blodgett films were utilized to assemble metal nanoparticles, to make free-standing hybrid polymer nanosheets, to examine the possibility of hybrid polymer nanoassemblies as luminescence sensor application, and to orient nonlinear optical (NLO) active molecules. Assembling nanomaterials such as nanoparticle and organic functional molecules through bottom-up approach make it possible to strengthen freestanding nanofilm stability, enhance luminescence from luminescent molecules and second harmonic light from NLO molecules under the influence of localized surface plasmon.