Introduction: Asian spices are globally recognized for their rich phytochemical composition. The bioactive compounds of Asian spices have significant potential to extend the biological applications of metal nanomaterials by increasing their surface area, stability, dispersion, and ecofriendliness.
Method: The present study is designed to prepare novel iron oxide (Fe2O3) and copper oxide (CuO) nanoparticles using an aqueous extract of Illicium verum (star anise), a traditional Asian spice as a reducing, capping & stabilizing agent. The synthesized nanoparticles have been characterized to study their molecular environment using Fourier Transform Infrared Spectroscopy (FTIR). Elemental composition was examined through the Energy Dispersive X-ray Spectroscopy (EDS). Scanning Electron Microscopy (SEM) revealed the size, shape, and other morphological characteristics of nanoparticles. The optical properties have been tested through Ultraviolet-Visible (UV) spectroscopy and the band gap energies of both Fe2O3 and CuO nanoparticles have been calculated by using the Tauc plot method, which explores its semiconductor applications. The catalytic applications of obtained nanoparticles have shown significant potential in the degradation of aqueous methyl orange dye (MO).
Results: Results revealed that Fe2O3 and CuO nanoparticles significantly increased the rate of reaction by decreasing the reaction time to 45 mins and 40 mins, respectively in comparison to the NaBH4 (60 mins). This shows that CuO has a larger surface area and more absorption capacity than Fe2O3 NPs. To examine the cause of value healthcare, the obtained materials have also been applied against various Gram-positive and Gram-negative bacteria. The bactericidal activity was compared with gentamicin, which showed both nanometals are moderate to strongly active against tested microbes.
Conclusion: The successful eco-friendly synthesis of metallic nanoparticles by using Asian spices and their applications in physical and biological sciences opens the door for the scientific community to develop and apply more novel and green nanomaterials in industrial and commercial areas.
Keywords: Illicium verum, iron oxide, copper oxide, nanoparticles, antibacterial, photocatalyst.