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Graphdiyne (GDY) is a new 2D carbon material different from graphene, and its ideal drug carrying and photothermal therapy efficacy had been noticed recently. Graphdiyne-oxide (GDYO), which few phototherapy researches had been reported, has more oxygen functional groups than GDY. Metal-organic framework materials Fe3O4@UiO-66-NH2 (FU) can covalently connect to GDYO layers and obtain covalent-organic framework-like structures FUGYO. FU enlarged interlamellar space of GDYO, which avoided the aggregation of FUGYO multiple layers. At the same time, more acetylenic bonds and hydrophilic group were exposed, which brings out advantages like stability, hydrophily, high drug-loading, as well as magnetic targeting and better magnetic resonance imaging efficacy. To promote cancer treatment effect and water solubility, we loaded chemotherapy drug doxorubicin (DOX) in FUGYO, then encapsulated FUGYO/DOX in phosphatidylcholine and fluorescent organic polymer BODIPY-PEG (BP) to integrate image-guided and synergistic therapy in one nanoparticle (BPFG/DOX). Due to the unique structure of BPFG/DOX, the π–π interaction between GDYO and BP improved photodynamic therapy efficiency. About 10 μg ml−1 BPFG/DOX have nearly 90% cell lethality to MCF-7 (human breast cancer cell line) cells with laser irradiation. In vivo, BPFG/DOX possessed ideal magnetic targeting and effectively inhibited tumor growth in 6 d. In conclusion, BPFG/DOX not only acts as an excellent tumor theranostic agent but also provides a scheme for applying GDYO in the biomedical region.

Employing atomic force microscopy, transmission electron microscopy and the second harmonic generation technique, we carefully explore the structural properties of 6-unit-cell-thick La0.8Sr0.2MnO3 films grown on SrTiO3 with atomically fat TiO2-terminated terraces on the surface. The results clearly demonstrate that the terraces on the surface of TiO2-terminated SrTiO3 can improve the layer-by-layer epitaxial growth of the manganite films, which results in uniform film coverage at the beginning of growth and thus reduces the substrate-induced disorder at or near the interface. Comparing the magnetic and transport properties of La0.8Sr0.2MnO3 films with the thicknesses varying from 6 unit cells to 80 unit cells grown respectively on as-received SrTiO3 and TiO2-terminated SrTiO3, it is found that these atomically flat terraces on the surface of TiO2-terminated SrTiO3 can greatly enhance the Curie temperature and conductivities of the ultrathin La0.8Sr0.2MnO3 films with thickness less than 50 unit cells, while no obvious difference is detected in the magnetic and transport properties of the 80 unit-cell thick films.