| Free-standing two-dimensional(2D) crystals with atomic thickness have attracted extensive attention in the academic world. The big specific area and the single dispersibility make them own unique electronic, optical, mechanical and biocompatible properties, and so on. In recent years, the study mainly focus on synthesis and improving the application value for these free-standing two-dimensional materials. Both of WS2 and Mn PS3 have layered structure, and tungsten element has a high absorption coefficient to the X-rays, the manganese element has a unique magnatic property, promising applications can be come true. In this study,we have synthesized the material of WS2 free-standing nanosheets,they not only have a perfect effect in CT imaging but also work as an outstanding NIR photothermal therapy agent. Based on the big atomic weight of tungsten element, it will have a bright CT imaging, On the other hand,the large atomic defects make it easier to produce a strong near-infrared(NIR) localized surface plasmon resonances(LSPRs).In the second part,we exfoliate Mn PS3 successfully, the manganese element can be used as magnetic resonance imaging contrast agents.The details of our studies are stated as following: Synthesis and applications in both CT imaging and photothermal therapy agent of WS2-PEG nanosheetsWe insert Li cation into the WS2 layer by a method of solvothermal,after this step,the precursor is got. We exfoliate the layered material to nanosheet by ultrasonic wave. To improve the solubleness and the biocompatibility, we design and synthesis WS2-PEG successfully. The product can used as X-ray CT contrast agents and NIR photothermal therapy agents. When theproduct was irradiated at 808 nm laser with a density of 1W/cm2 about 10 min, the temperature increase of the aqueous solution about 18.7 oC,and the photothermal conversion efficiency can up to 35%.On the other hand, The fitted values of CT and solubility of the material is more than two times larger than that of iohexol under the same conditions. In summery,the WS2 nanosheets can both use as as X-ray CT contrast agents and NIR photothermal therapy agents. Synthesis and applications in MRI contrst agent of Mn PS3 nanosheetsWe synthesis the Mn PS3 material by a simple method in solution,then get the Mn PS3 nanosheets in the same way as WS2 nanosheets,In the last,we treasure the magnatic property of Mn PS3 nanosheets, its longitudinal relaxivity at 0.5 T is about 0.46 m M-1s-1,showing that Mn PS3 nanosheets can be used as MRI contrast agents. |
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