Algae-mediated route to biogenic cuprous oxide nanoparticles and spindle-like CaCO₃: a comparative study, facile...

Biocompatible syntheses of Cu₂O nanoparticles are relatively low compared to some other reported metal oxides due to their low stability and requiring more carefully controlled synthetic conditions. In the present study, the efficiency of three brown algae (Cystoseira myrica, Sargassum latifolium and Padina australis) extracts collected from the Persian Gulf was evaluated in the biosynthesis of Cu₂O nanoparticles. A fast and simplified synthesis of Cu₂O nanoparticles with average size between 12 and 26 nm was successfully achieved through an eco-friendly method using the aqueous extracts of Sargassum latifolium and Cystoseira myrica. Whereas, under the same reaction conditions using Padina australis extract no Cu₂O nanoparticles were produced, and unexpectedly, the results approved the formation of spindle shaped CaCO₃ with average sizes of 1-2 μm in length and 300-500 nm in width. Structure, morphology and composition of the as-prepared products were characterized by XRD, FT-IR, UV-vis, TEM and FESEM analysis. This work confirms that the biomolecules present in algae have the ability to affect particle size, morphology, composition, and physicochemical properties of the synthesized particles. The Cu₂O nanoparticles prepared in this study were stable and exhibited efficient antibacterial and anticancer activity. This biosynthesis technique can be valuable in environmental, biotechnological, pharmaceutical and medical applications.