Biomedical and photocatalytic dye degradation studies of Cymbopogon citratus mediated copper oxide nanoparticles (CuO NPs)

This research presents a novel approach to synthesizing copper oxide nanoparticles (CuO-NPs) using Cymbopogon citratus (C. citratus) extract. The nanoparticles were thoroughly characterized using Fourier-transform infrared (FTIR), ultraviolet–visible (UV–vis) spectroscopy, X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). The UV–vis analysis revealed a surface plasmon resonance (SPR) peak at 250 nm, indicating the successful formation of CuO-NPs. XRD patterns confirmed the crystalline nature of the nanoparticles with distinct CuO reflections. FTIR examination identified the presence of flavonoids and phenolic compounds, which played crucial roles as capping and stabilizing agents during the nanoparticle synthesis process. FESEM displayed spherical CuO-NPs with an average size of 49 nm. These nanoparticles exhibited remarkable antioxidant activity, as evidenced by their high percentage inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH). Moreover, the synthesized CuO-NPs demonstrated potent antibacterial properties, inhibiting the growth of Escherichia coli and Staphylococcus aureus in a dose-dependent manner (5–15 μg/mL). The potential of CuO-NPs as anticancer agents was investigated using MTT and live/dead cell staining assays on MCF-7 (breast cancer) and Rhabdomyosarcoma (RD) cell lines. The results indicated a dose-dependent reduction in cell viability, with the highest viability observed in MCF-7 (89.5%) and RD (82%) cells at 25 μg/mL, decreasing to 41% at 800 μg/mL, while maintaining the viability of normal cells (NIH-3T3). Furthermore, the synthesized CuO-NPs exhibited excellent photocatalytic activity, degrading 97% of Rhodamine B (RhB) under solar illumination. Overall, the green-synthesized CuO-NPs displayed significant antibacterial, antioxidant, photocatalytic, and cytotoxic activities, highlighting their promising potential for various biomedical applications.