Engineering γ-Graphyne Quantum Dots for Photoactive Applications and In Vitro Bioimaging

Graphyne is the only known 2D material combining sp and sp 2 hybridization, with γ-graphyne identified as its most stable allotrope. However, its quantum dots (γ-GYQDs) remain largely unexplored. This study investigates diamondshaped and triangular γ-GYQDs using Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) simulations, focusing on stability, optoelectronic properties, and quantum confinement effects. We find that acetylenic bonds play a crucial role in stabilizing larger diamond-shaped γ-GYQDs. Functionalization has minimal impact on energy gaps, preserving key optical properties. Notably, the electronic structure aligns well for photoactive applications, with the HOMO level below the electrolyte’s I - /I 3 - redox potential and the LUMO above TiO 2 ’s conduction band. Additionally, size-dependent red-shifts in absorption and emission spectra suggest strong potential for photovoltaics and biomedical applications. Furthermore, γ-GYQDs exhibit distinct quantum confinement effects due to their acetylenic linkages, highlighting their promising optoelectronic behavior for next generation nanotechnology applications.