New progress in controlling the optical properties of graphene quantum dots based on strong magnetic field

Graphene quantum dots (gqds) are two-dimensional nanomaterials with small size In recent years, because of its stability, biocompatibility, fluorescence tunability, and easy to be removed by the kidney, it has great application in the integration of cancer diagnosis and treatment, and has attracted great attention in the biomedical field The optical absorption of the existing gqds used in photothermal therapy is mainly concentrated in the near infrared region 1 However, the absorption and scattering of skin and tissue make the laser penetration depth in the near infrared region and the light intensity in the target region greatly reduced It is difficult to adjust the optical absorption of gqds to near-infrared region 2 by means of doping, passivation and other surface post-treatment Recently, Wang Hui, researcher of the strong magnetic field science center of the Chinese Academy of Sciences, Chen Qianwang, Professor of the University of science and technology of China, and Nie Rongrong, Professor of Nanjing University, etc took the control of the optical absorption performance of gqds as the starting point, using phenol as the precursor, hydrogen peroxide as the oxidant, and using the solvothermal method under the magnetic field to prepare the gqds-9t-gqds with near-infrared two Zone optical absorption performance in one step Compared with the gqds (0t-gqds) synthesized under non-magnetic field, 9t-gqds showed obvious near-infrared two-region optical absorption (1070 nm) Meanwhile, 9t-gqds has 16.67% fluorescence quantum yield and 33.45% photothermal conversion efficiency In vivo, it was proved that 9t-gqds had significant inhibitory effect on tumor growth of mice in the fluorescence imaging guided near-infrared two zone photothermal cancer treatment The results were published in the international journal biomaterials (DOI: 10.1016 / j.biomaterials 2019.119700) under the title of "magic induced graphene quantum dots for imaging guided photothermal therapy in the second near infrared window" The research work was supported by NSFC, launching fund of Hefei Research Institute, collaborative innovation and cultivation fund of Hefei University Science Center, Key Laboratory of photovoltaic materials and energy conservation of Chinese Academy of Sciences, and Key Laboratory of medical physics technology of Anhui Province The experimental data under the relevant magnetic field are collected on the stable strong magnetic field experimental device.