One Pot Green Synthesis of Curmin Capped Gold Nanoparticles in Acidic Medium and its Catalytic Activities
Preparation of gold nanoparticles by green synthetic route has been of great interest for biomedical and catalytic investigation. In this manuscript, we have successfully prepared curcumin capped gold nanoparticles (Au NPs) using curcumin as a green synthetic routeby reducing Au3+ to Au0 in one pot synthesis procedure in the presence of Ag+ ion and CTAB micelle at pH 4. The particles are confirmed from surface Plasmon absorption peak of colloidal gold at ~572 nm and found to be spherical of diameter 50-70 nm, though few cylindrical shaped rods with a diameter of about 50-60 nm and length of about 100-120 nm are also observed. However, these nanoparticles aggregate in solution to form large assembly of 273 nm as found in DLS analysis. Curcumin capping of the gold nanoparticles has been established from UV-visible and fluorescence emission spectra. The emission of curcumin capped Au NPs illustrate vibronic peaks of curcumin indicating curcumin is surrounded by hydrophobic tail of CTAB while conjugating with Au NPs. The prepared curcumin capped Au NPs works as excellent nano-catalyst for the reduction of nitro-compound, 4-nitrophenol, compared to reduction of 4-nitrophenol in the absence of Au NPs.