Synthesis of copper sulfide nanoparticles on the basis functionalized nitrile butadiene rubber (NBR-26) was carried out by the method of successive ionic layer adsorption and the reaction (SILAR). The reaction was undertaken at room temperature. The XRD records show well-formed nanocrystalline particles of copper sulfide as Cu_1.8S with structure of cubic form. The crystallite size approximated 5 nm for Cu_1.8S nanocrystals. The band gap of Cu_1.8S nanoparticles is found to be 3 eV. SEM/EDX analyses showed that the synthesized materials are nanocomposites and the particle size of Cu_1.8S is in the range of 9–12 nm. Infrared spectroscopy  results illustrate that nanoparticles could grow on the –PO(OH)₂ functional groups of polymer. The formed nanocrystals are quantum dots  and can be used photoelectron transformation devices.