School of Chemistry and Materials Science, Nanjing University of Information Science and Technology, Nanjing 210044, China.
State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University, Guilin 541004, China.
Int J Mol Sci. 2022 Mar 17;23(6):3230. doi: 10.3390/ijms23063230.
Nitrogen doping and amino group functionalization through chemical modification lead to strong electron donation. Applying these processes to a large -conjugated system of graphene quantum dot (GQD)-based materials as electron donors increases the charge transfer efficiency of nitrogen-doped amino acid-functionalized GQDs (amino-N-GQDs), resulting in enhanced two-photon absorption, post-two-photon excitation (TPE) stability, TPE cross-sections, and two-photon luminescence through the radiative pathway when the lifetime decreases and the quantum yield increases. Additionally, it leads to the generation of reactive oxygen species through two-photon photodynamic therapy (PDT). The sorted amino-N-GQDs prepared in this study exhibited excitation-wavelength-independent two-photon luminescence in the near-infrared region through TPE in the near-infrared-II region. The increase in size resulted in size-dependent photochemical and electrochemical efficacy, increased photoluminescence quantum yield, and efficient two-photon PDT. Therefore, the sorted amino-N-GQDs can be applicable as two-photon contrast probes to track and localize analytes in in-depth two-photon imaging executed in a biological environment along with two-photon PDT to eliminate infectious or multidrug-resistant microbes.
通过化学修饰进行氮掺杂和氨基官能化会导致强烈的电子供体。将这些过程应用于基于石墨烯量子点 (GQD) 的大共轭体系的材料中，作为电子供体，可以提高氮掺杂氨基酸功能化 GQD（氨基-N-GQD）的电荷转移效率，从而增强双光子吸收、后双光子激发 (TPE) 稳定性、TPE 截面以及通过辐射途径的双光子发光，同时寿命降低和量子产率增加。此外，它还会通过双光子光动力疗法 (PDT) 产生活性氧。本研究中制备的经分类的氨基-N-GQD 通过近红外-II 区的 TPE 在近红外区表现出与激发波长无关的双光子发光。尺寸的增加导致了尺寸依赖性的光化学和电化学功效、增加的光致发光量子产率以及有效的双光子 PDT。因此，分类的氨基-N-GQD 可用作双光子对比探针，以在生物环境中执行的深度双光子成像中跟踪和定位分析物，以及进行双光子 PDT 以消除感染性或多药耐药的微生物。
