Combining two biocompatible singlet oxygen generators into a potent photoactive agent: Graphene quantum dots-curcuma hybrid

• Graphene quantum dots (GQDs) and curcumin form a water-dispersible complex via a simple, one-step procedure. • UV–Vis and FTIR analyses confirmed the formation of the GQD-Cur (peak at 370 nm and bands at 1509 cm −1 , 1274 cm −1 , and 1120 cm −1 ). • EPR spectroscopy showed 30 % higher singlet oxygen production for curcumin-modified GQDs. • Faster ABDA and DPBF degradation with GQD-Cur also suggests better singlet oxygen production. • GQD-Cur is a promising nanomaterial as a photosensitizer for photodynamic therapy. As a cutting-edge treatment strategy, photodynamic therapy (PDT) utilizes light-sensitive compounds to selectively destroy target cells, offering extensive possibilities for managing numerous medical conditions, including bacterial infections and tumors. Graphene quantum dots (GQDs), zero-dimensional nanomaterials, possess unique properties that make them ideal for biomedical applications, including high dispersibility, biocompatibility, and luminescent emission. In this study, we synthesized GQDs and modified them by incorporating curcumin, a natural compound known for its antimicrobial properties. Both UV–Vis and infrared spectroscopies confirmed the formation of the hybrid material. AFM and DLS analyses revealed an increase in particle size and changes in zeta potential, indicating successful incorporation of curcumin. Notably, the modified GQDs exhibited enhanced singlet oxygen production under blue light irradiation, as proven with EPR spectroscopy and ABDA degradation, demonstrating their potential as a photosensitizer of a new generation for PDT.