Single-molecule graphene quantum dots: enhancement of optical properties and promotion of photodynamic efficacy based on precise control of the electronic structure
Jintao Chen, Bin Li, D. S. Liu, Shiru Yin, Ji Qi, Zifeng Lü, Yi Liu, Tian Gao
Abstract
) induce a blue shift in photoluminescence (PL) emission, enhance fluorescence quantum yield, and improve photo-induced ROS production. Conversely, electron-withdrawing groups (-Br) cause emission red shift, reduce PL quantum yield, and completely suppress photodynamic activity. Notably, the alternately substituted 6Br-6Me-GQD exhibits enriched electron transfer pathways, demonstrating dual emission peaks and optimal photodynamic performance. Importantly, both 12D-A type and 6D-π-6A type GQDs maintain effective ROS generation under hypoxic conditions, addressing the critical limitation of conventional photosensitizers in oxygen-deprived tumor microenvironments. This work established a modular synthetic system for single-molecule GQDs with different D-A types and revealed the structure-property relationships governing optical characteristics and ROS generation capabilities, providing novel insights for the development of hypoxia-adaptive PDT nanomedicine.