Synthesis Of Grapheme Oxide/Selenium Nanoparticle Hybrids And Their Application In Photothermal Therapy

Graphene (Graphene) is a new material which has a single sheet-like structurecomposed of carbon atoms. This material has a two-dimensional structure, thethickness of an atom, is the basic component of all allotrope of carbon. Becausegraphene has excellent optical, elcctircal, thermal, mechanical and chemicalproperties, it was received worldwide attention of researches all over the world sincediscovered. To take advantage of the excellent characteristics and further optimizationof graphene, many researchers tried to make it as a carrier in the surface modificationof organic and inorganic nanoparticles and biomolecules (such as DNA, folic acid,doxorubicin, etc.), to prepare a series of hybird materials which has unique properties.Based on the special properties of graphene, graphene derivatives-graphene oxideand its various polymers, nano particles (metal, metal oxide semiconductor) complexhas also been rapid developed. This paper studies the modiifcation method ofselenium compounds on the graphene oxide surface, and makes a series ofcharacterizations for the structure and properties of the prepared graphemeoxide/hybrid materials, the application of these materials in the bio-imaging andphotothermal therapy are also discussed.The ifrst chapter outlines the structure, properties of graphene and its derivativesgraphene oxide and summarizes the method of preparing grapheme oxide/hybridmateirals which makes grapheme oxide as a carrier in the modiifcation of nanoparticleon the surfaces. The grapheme-based materials can be used in the biological area suchas gene delivery, drug delivery, imaging and photothermal therapy. Finally, theresearch idea of this thesis are proposed. The second chapter describes a method of preparing GO/BhSc〗 composites. Itwas prepared by a solvothcrinal method in which graphene oxide was made by amodiifed Hummers method was used as a carrier, diethyl ene glycol was as a solvent.B12SC3nanoparticlcs was deposited evenly in situ on the surface of graphene oxide.We explores optimal synthesis conditions including reaction temperature, time andstarting material ratio to modify selenium nanoparlicles in situ on the surfacc ofgraphene oxide,1liroiigh a series of spectra and electron microscopy characterizations,the structure and properties of GO/BiiSej nanomaterials were analyzed. The resultsshow that we can get hybrid materials with good morphology by the conditions of areaction temperature of200°C and a reaction time of3li and the nanoparticlcs arcuniformly distributed on the graphene oxide surfacc. In addition, we determined the invitro CT imaging of the GO/RiTSej nanomatcrial in aqueous solution, and found thaithis material showed better CT imaging properly than the same concentration ofiodine contrast agents. We also studied ihc phololhcrmal properties ol" CJO/BijSejnanomatcrial and its application in photothcrnial therapy at the cellular level. Thematerial has good light-heal conversion pcrlbniunict1, und it am be used forphotolhernial therapy.The main contenl of llic third chaptcr is using a high-temperature tlicnnalinjection method to prepared GO/Cii2-xSe nano hybrid materials with olcylaminc as asolvent. In the resulting hybrid material, I he Cii2.xSe naao]^arliclcs were evenlymodified on graphene oxide surface, with olcylaminc as a solvent. I he method ofpreparation of CJO is the same as the last chapter’s. Before starting the reaction. GOshould be dispersed in oleylamine, The cuprous chloride and selcnourca wereintroduced into threc-ncckcd (lask, scaled, then residual air inside were removed withnitrogen. With injecting the olcylaminc into ihc iwo llasks, ihc reaction was startedalter the cuprous chloride was completely dissolved, the GO solution was injected.Atfer reaching the set temperature, the selenium urea solution was quickly withdrawnand injected into the mixed solution of graphene oxide and cuprous chloridc, thereaction was terminated after luilTan hour. We finally obtained a hybrid material with(i() as the base and in-situ deposition of Cib-^Sc on it. By regulating the reaction conditions we obtained a hybird mateiral with pure, uniform size of nanoparticlesuniformly distributed on the surface of graphene oxide. Atfer the characteirzation ofthe mateiral, the photothermal properties of GO/Cu2-xSe nano hybrid material and itsapplication in cellular photothermal therapy were studied.Chapter IV is the conclusion of this paper, and we also give the prospects ofthese hybrid materials in molecular imaging and photothermal therapys.