In this paper, silver nanoparticles(Ag NPs) and Ag NPs/reduced graphene oxide(RGO) nanocomposites were prepared using lemon juice under microwave irradiation(MWI) and UV light irradiation. Ag NPs with face-centered cubic structure RGO peaks were observed by X-ray diffraction. The UV–Vis spectrum showed modifications in the absorption peaks of the Ag NPs with the concentration of the precursor solution and irradiation time, and the optimized condition was obtained for 20 min MWI and 60 s of UV light. Raman analysis confirmed the presence of RGO as D and G bands in the spectrum. Transmission electron microscopy analyses confirmed that the Ag NPs of size ranging from 3 to 8 nm were anchored onto the RGO sheets. The antibacterial properties of the Ag NPs/RGO nanocomposites were investigated using gram-negative bacteria. The results revealed that Ag NPs/RGO nanocomposites consisting of approximately 5 wt% Ag NPs can achieve antibacterial performance similar to that of neat Ag NPS. This method can be useful for the applications of Ag NPs-based nanocomposites, where minute amount of silver will be utilized. In this paper, silver nanoparticles (Ag NPs) and Ag NPs / reduced graphene oxide (RGO) nanocomposites were prepared using lemon juice under microwave irradiation (MWI) and UV light irradiation. Ag NPs with face-centered cubic structure RGO peaks were observed by X-ray diffraction. The UV-Vis spectrum showed modifications in the absorption peaks of the Ag NPs with the concentration of the precursor solution and irradiation time, and the optimized condition was obtained for 20 min MWI and 60 s of UV light. Raman analysis confirmed the presence of RGO as D and G bands in the spectrum. Transmission electron microscopy analyzes confirmed that the Ag NPs of size ranging from 3 to 8 nm were anchored onto the RGO sheets. The antibacterial properties of the Ag NPs / RGO nanocomposites were investigated using gram-negative bacteria. The results revealed that Ag NPs / RGO nanocomposites consisting of approximately 5 wt% Ag NPs can achieve antibacterial performance similar to that of neat Ag NPS. This me thod can be useful for the applications of Ag NPs-based nanocomposites, where minute amount of silver will be utilized.