Luminescent-labeled copolymers of 4-acryloylmorpholine and 2-dialkylaminoethyl methacrylates (2-dimethylaminoethyl methacrylate and 2-diethylaminoethyl methacrylate) of varied compositions and molecular masses were synthesized. Polarized luminescence method was used to study relaxation properties of the polymers in diluted aqueous solutions. The influence of copolymer composition, temperature, pH, ionic strength of solutions on structural and dynamic characteristics of the copolymers in solution was established. The obtained copolymers were used to synthesize silver nanoparticles with an average radius of 7–8 nm. Interaction between the luminescent-labeled copolymers and Ag ⁺ ions was studied. It was demonstrated that reduction of Ag ⁺ by the copolymers and formation of Ag° is accompanied by decrease in mobility of polymer chains due to adsorption of macromolecules on the surface of Ag° nanoparticles and formation of a stabilizing shell.