A NIR light activated self-reporting carbon dots assembly as phototheranostics for tumor photodynamic therapy

Photodynamic therapy (PDT) has emerged as a promising protocol for cancer therapy. However, real-time monitoring of PDT progress and accurate determination of the optimal treatment timing remain challenges. In this work, we selected carbon dots (CDs) and new indocyanine green (IR820) as building units to fabricate a smart nanotheranostics (CDs-IR820 assembly) with the characteristics of controlled release and real-time imaging to solve the time gap between diagnosis and treatment. The fabricated CDs-IR820 assembly locked the photosensitivity of the CDs and could degrade under 750 nm laser irradiation to achieve controlled release of the CDs, thus used for cell imaging and producing single oxygen under the white light. Besides, the released CDs could migrate from the mitochondria to the nucleus during the PDT process, indicating the cell activity, which facilitated the regulation of treatment parameters to achieve the precise PDT for cancer.