Dual role of ROS-dependent anti-cancer activity and photocatalytic degradation of graphene oxide against MCF-7 breast cancer cells and organic dye

Graphene oxide (GO), a two-dimensional nanomaterial, was synthesized using a modified Hummers' method and evaluated for its dual biomedical and environmental applications. Structural characterization confirmed the successful formation of GO, as evidenced by XRD (d-spacing of 10.23 Å), FTIR (hydroxyl, epoxy, carboxyl, and carbonyl functional groups), TGA (distinct weight loss patterns), and microscopic analyses (FE-SEM, EDX, and HR-TEM) revealing spherical and rod-like morphologies. Biologically, GO exhibited potent cytotoxicity against MCF-7 breast cancer cells in a concentration-dependent manner. The IC₅₀ concentration of the GO induced more apoptosis, nuclear membrane damage, mitochondrial dysfunction, and cytochrome c release through intracellular ROS generation, ultimately activating caspase-3 and caspase-9 pathways. These mechanistic findings were validated by fluorescence staining assays (AO/EB, DAPI, DCFH-DA, and rhodamine 123). In parallel, photocatalytic studies demonstrated that GO achieved 46.9% degradation of Rhodamine-B dye under visible light within 120 min, attributed to reduced electron-hole recombination and enhanced ROS generation. Collectively, these results highlight the multifunctionality of GO as both a promising anticancer nanomaterial targeting breast cancer and an efficient photocatalyst for environmental remediation of toxic dyes.