Electrochemically Engineered GQDs for Selective Tumor Targeting and Oxidative Nanotherapy in Triple-Negative Breast Cancer

We report a rapid and sustainable electrochemical method for producing graphene quantum dots (GQDs) from defect-rich graphene sheets using vitamin C as a redox-buffered exfoliant and sodium hydroxide to control the ionic environment. The resulting GQDs (3-10 nm) exhibit excitation-dependent green fluorescence, high aqueous dispersibility (ζ = -28.3 mV), and moderate oxidation with abundant oxygen functionalities. <i>In vitro</i> studies reveal selective cytotoxicity against triple-negative breast cancer (TNBC) cells via intracellular ROS generation, while sparing normal fibroblasts. <i>In vivo</i> fluorescence imaging in 4T1 tumor-bearing BALB/c mice confirms preferential tumor accumulation, renal clearance, and systemic biocompatibility, supported by blood biochemistry and histopathology. Compared with conventional GQD synthesis, this strategy offers faster reaction time, reduced chemical hazards, and improved therapeutic relevance. Overall, our approach introduces a clinically translatable, green nanoplatform for image-guided and ROS-amplified nanotheranostics in TNBC.