State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, P. R. China.
College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
ACS Appl Mater Interfaces. 2020 Mar 4;12(9):10781-10790. doi: 10.1021/acsami.9b20434. Epub 2020 Feb 25.
The evaluation of intracellular reactive oxygen species (ROS) would greatly deepen the understanding of cell metabolism/proliferation and tumor detection. However, current long-acting level tracking techniques for intracellular ROS remain unsuited to practical applications. To solve this problem, we synthesized cyclotriphosphazene-doped graphene quantum dots (C-GQDs) whose quantum yield is highly sensitive to ROS (increased by 400% from 0.12 to 0.63). Electron cloud polarization of oxidized cyclotriphosphazene rings in C-GQDs is confirmed to account for this novel optical property by density functional theory calculations and experimental results. In combination with excellent biological stability, C-GQDs achieve a long-acting evaluation of intracellular ROS level (more than 72 h) with an accuracy of 98.3%. In addition, recognition rates exceeding 90% are demonstrated to be feasible for eight kinds of tumor cell lines cultured with C-GQDs, which can also be expanded to in vivo detection. C-GQDs also show a high recognition rate (82.33%) and sensitivity (79.65%) for tumor cells in blood samples.
细胞内活性氧（ROS）的评估将极大地加深对细胞代谢/增殖和肿瘤检测的理解。然而，目前用于细胞内 ROS 的长效水平跟踪技术仍不适合实际应用。为了解决这个问题，我们合成了环三磷腈掺杂石墨烯量子点（C-GQDs），其量子产率对 ROS 高度敏感（从 0.12 增加到 0.63，增加了 400%）。通过密度泛函理论计算和实验结果证实，C-GQDs 中环三磷腈氧化环的电子云极化解释了这种新的光学性质。结合优异的生物稳定性，C-GQDs 可以实现对细胞内 ROS 水平的长效评估（超过 72 小时），准确率为 98.3%。此外，用 C-GQDs 培养的八种肿瘤细胞系的识别率超过 90%是可行的，这也可以扩展到体内检测。C-GQDs 对血液样本中的肿瘤细胞也表现出高识别率（82.33%）和灵敏度（79.65%）。
