The nanoscience is emerging field of the science and technology. In nanoscience research synthesizing green nanoparticles using green protocols are very good, effective technique, quite safe and ecofriendly technique compared to the conventional chemical and physical methods. These are used in the various field of science. These are used in the catalysis. Theses green and bio-based route for the preparation of the nanoparticles has good attention in the organic synthesis. These nano catalysts used for synthesis of heterocyclic compound. Imidazole and their derivatives are widely used. The imidazole and its derivatives are very important heterocyclic compounds. They have very good biological and pharmaceutical activity. In this we have prepared plant assisted tin oxide nanoparticles from the leaves of Ceropegia jainii plant by the green methods. The synthesized nanoparticles are characterized by various methods of analysis. These synthesized plants assisted nanoparticles are used for the synthesis of the heterocycles. We have developed the simple and highly efficient three component such as benzil, aromatic aldehyde and ammonium acetate under the microwave irradiation without any solvent. This reaction gives the 2,4,5-triarylimidazole derivatives with good yield and purity. This method is very simple and cost effective. Nano catalyst are green and recyclable with very less reaction time.