Recently, the research group of Yu Xuefeng, Shenzhen Advanced Institute of Technology, Chinese Academy of Sciences, cooperated with Prof. Zhu Jianhao, City University of Hong Kong and Prof. Zhang Han, Shenzhen University to develop a new type of ultra-small black phosphor quantum dots by members of the research group, Sun Zhengbo and Xie Hanhan. Photothermal treatment of tumors. The related paper, "Ultrasmall Black Phosphorus Quantum Dots: Synthesis and Use as Photothermal Agents," DOI: 10.1002 / anie.201506154 has been published by Angew. Chem. Int. Ed.) Inside Cover Story and was named Hot Paper. Due to its excellent properties, two-dimensional layered materials such as graphene and transition metal sulfide (TMDs) have become a kind of nanomaterials with broad prospects in basic research and potential applications. Inspired by the unique two-dimensional properties of graphene and TMDs, the conceptual new layered material of black phosphorus has drawn great interest from researchers all over the world. Phosphorus, as the fifteenth element in the periodic table, usually has chemiluminescent properties or generates no thermo-luminescence through chemical reactions. Black phosphorus is a black inert allotrope obtained after white phosphorus is subjected to high temperature and pressure and has a wave-like layered structure similar to but different from that of graphene sheets and having a semiconductor gap that graphene does not have. More importantly, the semiconductor bandgap is a direct bandgap where the bottom of the electronically conductive band (conduction band) and the top of the non-conductive band (valence band) are in the same position, whereas conventional silicon or molybdenum sulfide are all indirect bands Gap. This means that black phosphorus is directly coupled to light and the spectrum includes the entire visible to near infrared region. Therefore, the optical properties of black phosphorus are uniquely superior to those of graphene and other materials, including silicon and molybdenum sulfide, Optical field. The team pioneered this new two-dimensional material by using a combination of sonar probe and liquid bath sonication of the liquid stripping method to control the preparation of two-dimensional layered black phosphorous quantum dots with a lateral size of about 2.6 nm Monolayer Thickness Black Phosphor Quantum Dots. By examining the optical properties of this ultra-small black-phosphorus quantum dot and its effect on the survival of different cell lines, it was found to exhibit excellent near-infrared optical properties with an extinction coefficient of 14.8 Lg -1 cm -1 at 808 nm, light The thermal conversion efficiency of 28.4%, can significantly kill tumor cells under the irradiation of near-infrared laser and shows good biocompatibility in various cell lines. Two-dimensional layered structure of ultra-small black phosphorus quantum dots as another form of two-dimensional materials exhibit unique optical properties, and because phosphorus is an essential element in the body, making it unparalleled in the field of biomedical applications The advantages of using black phosphorous quantum dots as a highly efficient photothermal agent for the treatment of cancer have great potential. The research has been funded by the National Natural Science Foundation of China, the Hong Kong Research Foundation Comprehensive Research Fund, the City University of Hong Kong Strategic Research Fund and the Shenzhen Municipal Science and Technology Key Project.