In this thesis different UV-reactive polymers have been prepared and used for electroless plating and for the immobilization of nanoparticles. Gold nanoparticles were prepared according to the Turkevich method, characterized in-situ and coupled to the surface of photoreactive polymers. In a similar approach, lithographically structured patterns of aminofunctional silica nanoparticles on the surface of photoresponsive polymers were realized. Advancing to particles bearing a UV sensitive shell, silica nanoparticles were functionalized with photoreactive phenyl azide groups. These photoreactive nanoparticles were employed as non-migrating photocrosslinkers for C=C unsaturated polymers, and were immobilized at the surfaces of inert polymers by UV-induced coupling. Finally, the photo-reactive nanoparticles were covered with a polyethylene glycol shell by UV induced "grafting-to" reaction, which ensures a better compatibility of the particle with a wide variety of matrix polymers.