Method for obtaining colloidal solutions of silver nanoparticles, according to which an aqueous solution of argentum salt and an extract from waste plant material obtained under ultrasonic extraction conditions are obtained, the aqueous solution of silver salt is combined with an extract from waste plant material, which is both a reducing agent and a stabilizer, leading to the reduction of silver and the formation of its nanoparticles. A low-temperature eutectic solvent with a viscosity of 20000-18000 mPa·s is used as an extractant of the plant extract, and the ratio of the volumes of a solution of 0.01 M silver salt AgNO3 and plant extract is (1±0.1):(2±0.11) wt%. The method provides for the production of sedimentation-stable silver nanoparticles in a colloidal solution
