Green synthesis of (CeO2)-(CuO) nanocomposite, analytical study, and investigation of their anticancer activity against Saos-2 osteosarcoma cell lines

[Display omitted] •Chemical co-precipitation, a brand-new, easy-to-use, low-cost method, was used to create (CeO2)-(CuO) nanocomposite.•New compound of (CeO2)-(CuO) NPs by chemical method.•New compound which consider as nontoxic material.•Study the effect of (CeO2)-(CuO) NPs on characterization of the structure and optical properties.•Test study of (CeO)-(CuO) NPs on Anticancer activity 24 h and 48 h for Saos-2 cell line.•The half-maximal inhibitory concentration (IC50) of (CeO2)0.7 (CuO)0.3 NPs the IC50 value as 110.4 µg/ml at 24 h. A relatively low IC50 value was 59.18 µg/ml at 48 h. Osteosarcoma is regarded as a very dangerous malignancy that primarily affects lengthy bones. Widespread metastasis, particularly to the lungs, and low survival rates of 19–30 % are the outcomes. Chemical co-precipitation, a brand-new, easy-to-use, low-cost method, was used to create (CeO2)-(CuO) nanocomposite. It involved reacting an aqueous extract of Fenugreek leaves with dehydrated metal nitrate salts, with the best reaction conditions being (0.8 and 0.7) M for CeO2 and (0.2 and 0.3) M for CuO and the best pH 7 at 60 °C. X-ray diffraction, UV–visible, field emission scanning electron microscopy (FESEM), spectroscopy of energy-dispersive X-rays (EDX), and TEM analysis were used to identify the (CeO2)-(CuO) nanocomposite. According to the XRD data, the (CeO2) and (CuO) NCs' diffraction peaks showed cubic and monoclinic structures with average crystallite sizes of 13.5 and 15.4 nm, respectively.The composite nanoparticles' mean size of (7.2, 10.96) nm is consistent with low agglomeration, as determined by FESEM and TEM studies. UV–VIS measurements indicated a blue shift of the energy gap values from 4.3 eV at x = 0.7 M for (CeO2) and (CuO) to 4.7 eV at x = 0.8 M for (CeO2) and (CuO), respectively. An MTT test on the Saos-2 cell line was used to assess the activity of the generated nanoparticles. The data were statistical. Nanocomposite of (CeO2) and (CuO) were (7.2, 10.96) nm at (x = 0.8, 0.7), respectively, in size. The Saos-2 osteosarcoma cell lines were used to compare the effectiveness of (CeO2) and (CuO) nanocomposite as an anti-tumor agent with letrozole. The half-maximal inhibitory concentration IC50 value was 124 µg/ml at 24 h. A relatively low IC50 value was 71.93 µg/ml at 48 h. As for the results (CeO2)0.7(CuO)0.3 NPs, the killing rate was 14.83, 25.19, 39.2, 57.47, and 80.76 %, respectively. The killing rate after 48 h was 19.95, 32.26, 61.93, 81.17, and 95.74