The use of drug nanocarriers with effective drug loading can be effective in cancer treatment. In this study, graphene oxide (GO)/agarose (Aga)/starch (S) nanocarriers were made to deliver the 5-Fluorouracil (5-FU) as an anti-cancer drug to suppress breast cancer cells. The X-ray-diffraction analysis (XRD), Fourier-transform-infrared spectroscopy (FTIR), and water-in-oil (w/o) emulsification methods, zeta potential, and Dynamic-Light-Scattering (DLS) were employed for analysis. The results show that all materials are homogeneously placed next to each other. The efficiency of drug entrapment and loading in this nanocarrier was obtained as 87.25% and 46.5%, respectively, which is a suitable and significant amount. The kinetics and release of the drug show that the synthesized nanocarrier is sensitive to pH, and its release is stable. Flow cytometry outcomes showed apoptosis in cancer cells. This research’s outcomes are potent for the development and expansion of targeted drug delivery and medicinal nanomaterials based on GO/Aga/S.