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 μg/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.

背景：基于金纳米颗粒的各种杰出的物理和化学特性，它们在工业和医学的多个领域具有广泛的应用，例如催化，生物传感器和药物递送。与化学方法相比，生物合成是一种经济且毒性较小的过程，因此它是纳米颗粒合成的更好替代方法。在这项研究中，选择了一种环境友好的方法来利用姜黄生产金纳米颗粒。

方法：使用根茎线虫的碱性水提取物作为还原剂和稳定剂，通过生物还原HAuCl4制备AuNP。通过紫外线-可见光谱法定期监测AuNP的形成。通过X射线衍射，能量色散光谱，扫描电子显微镜，透射电子显微镜和傅立叶变换红外（FTIR）光谱对获得的AuNP进行表征。评价了AuNP的催化活性和毒性。

结果：从这项研究中获得的AuNPs大多为球形，大小约为15 nm。FTIR光谱证实了参与金生物还原过程的根茎黄连提取物衍生的官能团的存在。浓度为0.5μg/ ml的生物合成的AuNPs对刚果红的染料降解具有催化活性。结果表明，这种生物型AuNPs对斑马鱼的胚胎和所有测试的细胞系均无毒性。

结论：通过简单，环保，廉价的方法，成功地利用了黄花根茎提取物制备了具有催化活性的生物相容性AuNPs。所得AuNPs的这种催化活性可能对工业应用以及纳米科学和纳米技术有用。