In an unprecedented approach, p–n heterojunction nanosheets comprising ∼5 nm thick p-type MoS₂ nanoplates integrated onto n-type nitrogen doped reduced graphene oxide (n-rGO) have been employed for photodynamic therapy (PDT). When near infrared (NIR) light with 980 nm wavelength was irradiated on this nanocomposite, effective electron–hole separation was obtained across the heterojunction. The nanosheets were modified with lipoic acid functionalized poly(ethylene glycol) to provide better biocompatibility and colloidal stability in physiological solution. The surface decorated 3–5 nm MnO₂ nanoparticles (NPs) triggered the disproportionation of intracellular H₂O₂ which improved generation of reactive oxygen species (ROS) for enhanced PDT cancer therapy, studied in vitro. The role of N-doping in rGO and the effect of immobilization of MnO₂ NPs were systematically investigated by control experiments. Our smartly designed p-MoS₂/n-rGO–MnO₂–PEG nanosheets outperform conventional PDT agents by overcoming limitations such as low absorption band, unfavourable bioavailability and limitations in tissue oxygenation.

中文翻译：

---

硫化钼还原氧化石墨烯 p-n 异质结纳米片与锚定氧生成二氧化锰纳米粒子，用于增强光动力治疗†

在一种前所未有的方法中，包含集成到n型氮掺杂还原氧化石墨烯（n-rGO）上的~5 nm厚p型MoS ₂纳米板的p-n异质结纳米片已被用于光动力疗法（PDT）。当波长为 980 nm 的近红外 (NIR) 光照射到这种纳米复合材料上时，异质结上实现了有效的电子-空穴分离。用硫辛酸功能化的聚乙二醇对纳米片进行修饰，以在生理溶液中提供更好的生物相容性和胶体稳定性。体外研究表明，表面装饰的 3-5 nm MnO _{2纳米粒子 (NP) 引发细胞内 H 2} O ₂的歧化，从而改善活性氧 (ROS) 的产生，从而增强 PDT 癌症治疗。通过对照实验系统地研究了N掺杂在rGO中的作用以及MnO ₂ NPs的固定化效果。我们巧妙设计的 p-MoS ₂ /n-rGO–MnO ₂ –PEG 纳米片克服了低吸收带、不利的生物利用度和组织氧合限制等限制，优于传统的 PDT 制剂。