Synthesis and Characterization of Gold Nanoparticles by Tryptophane

Problem statement: Preparation and synthesis of gold nanoparticles with small size and suitable stability is very important and applicable particularly in medicine. In this study, we have prepared gold nanoparticles by chemical reduction method employing L-Tryptophane as a reducing agent for ionic gold. Approach: The gold nanoparticles are the most employed amongst the different metallic nanoparticles in the fields of nanomedicine and nanobiotechnology. Therefore, the employed method should provide suitable particle size, shape and particle distribution in order to obtain nanoparticles of high activity and efficiency indicating the importance of the technique. In this study, HAuCl₄ .3H₂O, L-Tryptophane and polyethyleneglycol (PEG) were used to produce AuCl^-₄ ions. They were acted as pre-material, reducing and stabilizing agents respectively. Results: The size, distribution and formation of gold nanoparticles were confirmed by Transmission Electron Microscopy (TEM) indicating the diameter of gold nanoparticles at the range of 10-25 nm and UV spectroscopy. The formed nanoparticles showed the highest absorption at 518 nm. Conclusion: The gold nanoparticles were stable in PEG1000. Since these nanoparticles have suitable size distribution they can be considered as a suitable candidate to be employed in nanomedicine and nanobiotechnology.