Developing a nanomaterial, for use in highly efficient dual-modality two-photon photodynamic therapy (PDT) involving reactive oxygen species (ROS) generation and for use as a two-photon imaging contrast probe, is currently desirable. Here, graphene quantum dots (GQDs) doped with nitrogen and functionalized with an amino group (amino-N-GQDs) serving as a photosensitizer in PDT had the superior ability to generate ROS as compared to unmodified GQDs. Multidrug-resistant (MDR) species were completely eliminated at an ultralow energy (239.36 nJ pixel^–1) through only 12 s two-photon excitation (TPE) in the near-infrared region (800 nm). Furthermore, the amino-N-GQDs had an absorption wavelength of approximately 800 nm, quantum yield of 0.33, strong luminescence, an absolute cross section of approximately 54 356 Göeppert–Mayer units, a lifetime of 1.09 ns, a ratio of the radiative to nonradiative decay rates of approximately 0.49, and high two-photon stability under TPE. These favorable properties enabled the amino-N-GQDs to act as a two-photon contrast probe for tracking and localizing analytes through in-depth two-photon imaging in a three-dimensional biological environment and concurrently easily eliminating MDR species through PDT.

中文翻译：

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双光子激发下双模式光动力疗法和生物成像中的抗菌氨基官能化氮掺杂石墨烯量子点消除多药耐药物种。

目前期望开发一种纳米材料，以用于涉及活性氧（ROS）产生的高效双模态双光子光动力疗法（PDT）中，并用作双光子成像对比探针。在此，与未修饰的GQD相比，在PDT中掺杂有氮并被用作光敏剂的氨基（氨基-N-GQD）官能化的石墨烯量子点（GQD）具有更高的生成ROS的能力。以超低能量（239.36 nJ像素^–1）完全消除了多药耐药（MDR）种类）只能通过近红外区域（800 nm）中的12 s两光子激发（TPE）。此外，氨基N-GQD的吸收波长约为800 nm，量子产率为0.33，强发光，绝对截面约为54 356 Göeppert–Mayer单位，寿命为1.09 ns，辐射与非辐射衰减率约为0.49，并且在TPE下具有很高的双光子稳定性。这些有利的特性使氨基N-GQD可以用作双光子对比探针，通过在三维生物环境中进行深入的双光子成像来跟踪和定位分析物，并同时通过PDT轻松消除MDR物种。