Synthesis Of Ternary Two-dimensional Transition Metal Sulfides Nanomaterials And Their Applications In Tumor Imaging And Optical Therapy

Two-dimensional transition metal sulfides nanomaterials are a new type of two-dimensional nanomaterials emerging after graphene nanomaterials.Due to the changes of structures and dimensions,two-dimensional transition metal sulfides nanomaterials have unique properties different from their bulk structure,such as high electron mobility,large specific surface area,excellent optical properties and so on.Because of their unique physical and chemical properties,binary two-dimensional transition metal sulfides nanomaterials have broad applications in the fields of energy,catalysis,optoelectronic devices,biomedicine and so on.However,the development of ternary two-dimensional transition metal sulfides in the field of biomedicine is still in the initial stage.Compared with the binary two-dimensional transition metal sulfides,the ternary two-dimensional transition metal sulfides have higher degree of freedom and adjustability due to the diversity of their composition.Furthermore,the ternary two-dimensional transition metal sulfides have more interesting characteristics due to their stoichiometric changes and synergistic effects.These novel properties make them have great potential in the field of tumor imaging and treatment.This paper mainly studied the preparation of FePS₃nanosheets and metal-phase MoWS₂nanodots,and their applications in tumor imaging and treatment.The main work was divided into the following two aspects:In the first part,we synthesized FePS₃crystals by chemical vapor transport（CVT）and then prepared FePS₃-PEG nanosheets by sonicating and in-situ modifying them with PEG-NH₂.The morphology and structure of prepared FePS₃-PEG nanosheets were characterized and analyzed,and their photothermal properties and the performance of magnetic resonance imaging were discussed.It is found that FePS₃-PEG nanosheets have excellent photothermal performance at 808 nm with the extinction coefficient of 14.1 L·g^-1·cm^-1and the photothermal conversion efficiency of 21.6%,and also have good T₁-weighted magnetic resonance imaging performance with the relaxation rate r₁of2.69 m M^-1·S^-1.FePS₃-PEG nanosheets will be a novel efficient photothermal therapy agent with a great magnetic resonance imaging function and can realize the integration of diagnosis and treatment.In the second part,we synthesized MoWS₂crystals by chemical vapor transport（CVT）and then prepared metal-phase MoWS₂nanodots by ball milling/butyllithium-intercalation exfoliation.The morphology and structure of the prepared metal-phase MoWS₂nanodots were characterized and analyzed,and their photothermal properties and the performance of photoacoustic imaging were discussed.Experimental results show that metal-phase MoWS₂nanodots have excellent photothermal performance at 785 nm with the extinction coefficient of 9.6 L·g^-1·cm^-1and the photothermal conversion efficiency of 22.2%.They have good photothermal stability and photoacoustic imaging performance,and can realize near-infrared photothermal therapy of tumors under the guidance of photoacoustic imaging in vivo.The excellent imaging performance and photothermal properties of the ternary two-dimensional transition metal sulfides nanomaterials have broad application prospects in the field of tumor imaging and therapy,which is of great significance for the development of transition metal sulfides nanomaterials in the field of biomedicine.