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. 2021 Sep 7;22(18):9695. doi: 10.3390/ijms22189695.
There is an urgent need for materials that can efficiently generate reactive oxygen species (ROS) and be used in photodynamic therapy (PDT) as two-photon imaging contrast probes. In this study, graphene quantum dots (GQDs) were subjected to amino group functionalization and nitrogen doping (amino-N-GQDs) via annealing and hydrothermal ammonia autoclave treatments. The synthesized dots could serve as a photosensitizer in PDT and generate more ROS than conventional GQDs under 60-s low-energy (fixed output power: 0.07 W·cm) excitation exerted by a 670-nm continuous-wave laser. The generated ROS were used to completely eliminate a multidrug-resistant strain of methicillin-resistant (MRSA), a Gram-positive bacterium. Compared with conventional GQDs, the amino-N-GQDs had superior optical properties, including stronger absorption, higher quantum yield (0.34), stronger luminescence, and high stability under exposure. The high photostability and intrinsic luminescence of amino-N-GQDs contribute to their suitability as contrast probes for use in biomedical imaging, in addition to their bacteria tracking and localization abilities. Herein, the dual-modality amino-N-GQDs in PDT easily eliminated multidrug-resistant bacteria, ultimately revealing their potential for use in future clinical applications.
迫切需要能够高效产生活性氧（ROS）并可作为双光子成像对比探针用于光动力疗法（PDT）的材料。在这项研究中，通过退火和水热氨高压釜处理，使石墨烯量子点（GQDs）进行氨基官能化和氮掺杂（氨基-N-GQDs）。合成的点可在 PDT 中用作光敏剂，并在由 670nm 连续波激光施加的 60 秒低能量（固定输出功率：0.07W·cm）激发下比常规 GQDs 产生更多的 ROS。所产生的 ROS 可完全消除耐甲氧西林金黄色葡萄球菌（MRSA）的多药耐药株，这是一种革兰氏阳性菌。与常规 GQDs 相比，氨基-N-GQDs 具有优越的光学性能，包括更强的吸收、更高的量子产率（0.34）、更强的发光和在暴露下的高稳定性。氨基-N-GQDs 的高光稳定性和固有发光使其适合用作生物医学成像的对比探针，此外还具有细菌跟踪和定位能力。在这里，PDT 中的双模式氨基-N-GQDs 可轻松消除多药耐药菌，最终揭示了其在未来临床应用中的潜力。
