Carbon dots that exhibit near-infrared fluorescence (NIR CDs) are considered emerging nanomaterials for advanced biomedical applications with low toxicity and superior photostability and targeting compared to currently used photoluminescence agents. Despite progress in the synthesis of NIR CDs, there remains a key obstacle to using them as an in vivo theranostic agent. This work demonstrates that the newly developed sulfur and nitrogen codoped NIR CDs are highly efficient in photothermal therapy (PTT) in mouse models (conversion efficiency of 59%) and can be readily visualized by photoluminescence and photoacoustic imaging. The real theranostic potential of NIR CDs is enhanced by their unique biodistribution and targeting. Contrary to all other nanomaterials that have been tested in biomedicine, they are excreted through the body's renal filtration system. Moreover, after intravenous injection, NIR CDs are accumulated in tumor tissue via passive targeting, without any active species such as antibodies. Due to their accumulation in tumor tissue without the need for intratumor injection, high photothermal conversion, excellent optical and photoacoustic imaging performance, and renal excretion, the developed CDs are suitable for transfer to clinical biomedical practice.

CAS Key Laboratory do Health Informatics Shenzhen Institutes of Advanced Technology Shenzhen 518055 China

Department of Biomedical Engineering Southern University of Science and Engineering Shenzhen Guangdong 518055 China

Department of Physical Chemistry Faculty of Science Regional Centre of Advanced Technologies and Materials Palacký University Olomouc 783 71 Olomouc Czech Republic

Jilin Provincial Tumor Hospital Changchun China

Research Laboratory for Biomedical Optics and Molecular Imaging Institute of Biomedical and Health Engineering Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China

School of Physical Sciences University of Chinese Academy of Sciences Beijing 100190 China

State Key Laboratory of Luminescence and Applications Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences 3888 Dong Nanhu Road Changchun 130033 China

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