グラフェン量子ドットのサイズと形状を特徴付けるための画期的なツールとしての表面プラズモン共鳴

Graphene quantum dots (GQDs) exhibit size- and shape-dependent properties that critically influence their optical and electronic behavior, yet their reliable nanoscale characterization remains challenging. Here, we introduce a diffusion-based surface plasmon resonance (D-SPR) workflow that enables quantitative, shape-sensitive characterization of GQDs beyond conventional spherical approximations. Using sustainably synthesized GQDs derived from banana peels via optimized microwave-assisted methods, D-SPR resolves distinct particle populations, distinguishing monodisperse disk-like GQDs with average lateral dimensions of ≈2.5 nm from larger, polydisperse structures averaging ≈20 nm. These results are in excellent agreement with HR-TEM and DLS measurements. Crucially, unlike conventional DLS, D-SPR exploits diffusion-geometry coupling to directly identify non-spherical, disk-like GQD morphologies, supported by computational and mathematical modeling. This label-free approach delivers rapid, high-sensitivity size and shape resolution using minimal sample volumes, establishing D-SPR as a powerful complementary tool for the advanced characterization of carbon-based nanomaterials.