Optimization of Synthesis Conditions of spherical gold nanoparticles towards cost-efficient applications in medical fields

Aim and Background: Gold nanoparticles (AuNPs) have great potential to contribute to numerous application fields of biomedicine, which are highly dependent on their physicochemical properties, such as size and shape. Due to the final characteristics, nanoparticles (NPs) are primarily affected by different factors of reaction conditions; this study aimed to evaluate the effects of manipulating the main physical parameters of Turkevich method to optimize the fabrication of citrated capped AuNPs in a spherical shape, desirable final size, and efficiency. Methods: Various experiments of citrate-capped spherical AuNPs synthesis were designed to study the roles of a wide range of initial pH values and temperature of reaction, Na3Cit/HAuCl4 molar ratio, and two order reagent additions, method I and method II, in the final characterizations and reaction efficacy. NPs synthesized with different experiments were characterized by DLS, UV-Visible, and FT-IR spectroscopy. Furthermore, NPs obtained from optimized synthesis conditions were more detailed using UV-Visible, TEM, and XRD. Results and discussion: The final size and synthesis efficacy of citrated capped spherical AuNPs were significantly affected by all studied synthesis parameters and the order addition of reagents. The higher initial reaction temperature and Na3Cit/HAuCl4 Molar ratio provided a smaller particle size with desirable synthesis efficacy. Besides, final optimized NPs were provided in cubic crystal structures, and each NP s single crystal was obtained. Conclusion: The optimizing synthesis conditions could improve size distribution, morphology, crystallite size, and structures of final NPS, as well as efficiency, which is a principal factor associated with future cost-effective productions on large scales