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Treatment in combination with real-time monitoring of dynamic organelle changes is of great significance for evaluating therapeutic efficacy. However, it remains highly challenging to realize such specific treatment and monitoring in organelles. Herein, we developed one kind of red emissive two-photon carbon dots (TP-CDs) via an N doping strategy for nucleolus-targeted treatment combined with real-time monitoring of dynamic changes in the nucleolus. In the TP-CD system, N doping endows TP-CDs with intrinsic two-photon excitation, red emission at 605 nm, and singlet oxygen (1O 2) production under 638 nm laser irradiation. More importantly, N heterocycles induced by doping offers significant affinity for TP-CDs toward RNA to realize specific self-targeting toward nucleolus and fluorescence variation during the photodynamic therapy (PDT) via the cleaving of RNA chain by 1O 2 to dissociate TP-CDs@RNA complex. By combining 1O 2 production, fluorescent variation during the PDT process, long-wavelength excitation and emission characteristics, as well as specific self-targetability of nucleolus, TP-CDs can be considered as a kind of "smart" CDs to realize treatment in combination of real-time dynamic changes in nucleolus for the first time. [Display omitted] [ABSTRACT FROM AUTHOR]

It is of extreme importance to engineer the structural characteristics of carbon dots (CDs) to satisfy their practical applications in imaging and medical treatments. Here, Cu,N-doped CDs ( Cu,N -CDs) are a new class of near-infrared-(NIR) light-induced therapeutic agents that were prepared by a one-step hydrothermal method using EDTA·2Na and CuCl 2 . Specifically, Cu ΙΙ was located in the inner of Cu,N -CDs via N-Cu-N complexation, endowing NIR absorption for the production of heat and reactive oxygen species. The relationships between the hydrothermal temperature, NIR absorption, and intrinsic biological activity of the Cu,N -CDs were examined. The hydrothermal temperature significantly affected the latter two when the Cu content in the Cu,N -CDs was changed. The Cu,N -CDs at 180 °C were examined for cancer phototherapeutics in vitro and in vivo . The Cu,N -CDs markedly inhibited cancer via synergistic photothermal/photodynamic therapies. In addition, the Cu,N -CDs could also act as one kind of fluorescence cell-imaging agent and IR thermal imaging agent to visualize the in vitro and in vivo treatment process, respectively. Thus, the present study provides a promising new method to prepare CDs with NIR absorption feature for multifunctional cancer theranostic applications. [ABSTRACT FROM AUTHOR]