Green Synthesis of Gold Nanoparticles using Neem Fruit Pulp Extract and their Applications in Catalytic and Antioxidant Activities

Gold nanoparticles (AuNPs) were synthesized using an eco-friendly method involving Azadirachta indica (neem) fruit pulp extract. The characterization of the synthesized AuNPs were confirmed through UV–visible spectroscopy, FT-IR, DLS, XRD, EDX, AFM and HR-TEM techniques. The appearance of a dark brown colour visually indicated the formation of AuNPs, which was supported by a UV-visible absorbance peak around 455 nm. HR-TEM analysis revealed that the nanoparticles were spherical and averaged 20 nm in size. The synthesized AuNPs demonstrated significant antioxidant activity against DPPH. Additionally, they exhibited exceptional catalytic performance in the reduction of 4-nitrophenol and methylene blue dye when used with sodium borohydride. These findings suggest that the formation and applications of AuNPs could be valuable for advancements in pharmaceuticals and nanotechnology.