Carbon dots (CDs) are an emerging class of nanomaterials with intriguing photophysical properties. Recently, achieving room-temperature phosphores-cence (RTP) for CDs have attracted considerable attention for biomedical and information applications. However, the CDs based RTP materials generally require the use of polymeric and inorganic matrix to provide the rigid environments, which remains a great challenge to obtain matrix-free CDs with RTP. Herein, a novel supramolecular strategy based on strong interparticle interactions has been developed to attain this objective, by covalent decoration of ureido-pyrimidinone (UPy, a multiple hydrogen bonding unit) on the surface of CDs. Structural characterizations validated the core-shell structure of the as-prepared CDs (EDTA-CDs) and demonstrated the successful attachment of UPy via post-modification (UPy-CDs). The presence of UPy recognition units render the strong hydrogen bonding between UPy-CDs, which stabilizes the triplet state via rigidifying effect. As a result, UPy-CDs exhibit matrix-free efficient RTP (λem = 534 nm) with high brightness and long lifetime (33.6 ms) in the solid state. Owing to the dual-emission character, we further explored the application potential of UPy-CDs in information encryption and anti-counterfeiting. Overall, this work provides a new and facile strategy for achieving matrix-free phosphorescent CDs with elegant incorporation of supramolecular chemistry.
Since the rapid development of nanomedicine in oncotherapy, multiple nanomaterials are adopted to regulate the immune system in cancer individuals. Tumor immunotherapy enhances the immune function of patients to achieve the purpose of killing tumor cells by utilizing the organism immune mechanism. As emerging inorganic carbon nanoparticles, carbon dots (CDs) have been found as photosensitizers, vaccines, immunoadjuvants, and so on for cancer treatment due to their unique structure and property, such as effective platforms for drug delivery, immunomodulation, and phototherapy. In this review, we mainly discuss the recent application of CDs in tumor immunotherapy and the prospects of CDs in the field of immune medicine. By assessing the achievements and challenges of CDs in tumor immunotherapy, our review would provide mechanistic insights into the evolution of future nanomedicine.