Synthesis of triangular silver nanoparticles stabilized by graphene quantum dots

Metallic nanoparticles exhibit physicochemical properties that are strongly dependent on size, shape, and composition. Among them, triangular silver nanoprisms (t‑AgNPs) are particularly attractive for biomedical applications due to their localized surface plasmon resonance (LSPR) in the near‑infrared region (700–800 nm), which overlaps with the therapeutic window for photothermal and photodynamic therapies. However, their high surface energy renders them unstable, especially in chloride‑containing physiological media, limiting practical use. In this work, we report a surfactant‑free synthetic route in which graphene quantum dots (GQDs) [1] act not only as stabilizing agents but also as morphological directors, promoting the formation of truncated‑pyramidal silver nanostructures with lateral size below 60 nm and heigh up to 15 nm. Our findings establish a novel pathway for producing stable surfactan-ree nanohybrids. These hybrid nanostructures hold promise as next generation agents for advanced medical therapies, bridging antibacterial, anticancer, and phototherapeutic applications.