Characterization of Biocompatible Gold Nanoparticles Synthesized by using Curcuma xanthorrhiza and their Catalytic Activity

Background: Based on various distinguished physical and chemical properties of gold nanoparticles, they have far wide applications in several areas of industry and medicine, such as catalysis, bio-sensor and drug delivery. Compared to a chemical method, biological synthesis is an economical and less toxic process, thus it is a better alternative for nanoparticle synthesis. In this study, an environmentally friendly method was chosen to produce AuNPs using Curcuma xanthorrhiza. Methods: Alkaline aqueous extract of C. xanthorrhiza rhizomes, which acts as a reducing and stabilizing agent was used to produce AuNPs by bio-reduction of HAuCl4. The formation of AuNPs was periodically monitored by UV-visible spectroscopy. The obtained AuNPs were characterized by Xray diffraction, energy dispersive spectroscopy, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared (FTIR) spectroscopy. Catalytic activity and toxicity of the AuNPs were evaluated. Results: The AuNPs obtained from this study mostly were spherical in shape with approximately 15 nm in size. The presence of functional groups derived from C. xanthorrhiza rhizome extract involved in the gold bio-reduction process was confirmed by the spectrum of FTIR spectroscopy. The biosynthesized AuNPs at the concentration of 0.5 mu g/ml had catalytic activity in dye degradation of Congo red. The results showed that this biogenic AuNPs did not cause any toxicity to zebrafish embryos and all tested cell lines. Conclusion: The biocompatible AuNPs with catalytic activity were successfully fabricated with C. xanthorrhiza rhizome extract by simple eco-friendly and inexpensive method. This catalytic activity of the obtained AuNPs is potentially useful for industrial applications as well as nanoscience and nanotechnology.